A flexible counter electrode(CE) for dye-sensitized solar cells(DSCs) has been fabricated using a micro-porous polyvinylidene fluoride membrane as support media and sputtered Pt as the catalytic material.Non-conventio...A flexible counter electrode(CE) for dye-sensitized solar cells(DSCs) has been fabricated using a micro-porous polyvinylidene fluoride membrane as support media and sputtered Pt as the catalytic material.Non-conventional structure DSCs have been developed by the fabricated CEs. The Pt metal was sputtered onto one surface of the membrane as the catalytic material. DSCs were assembled by attaching the Ti O2 electrode to the membrane surface without Pt coating. The membrane was with cylindrical pore geometry. It served not only as a substrate for the CE but also as a spacer for the DSC. The fabricated DSC with the flexible membrane CE showed higher photocurrent density than the conventional sandwich devices based on chemically deposited Pt/FTO glass, achieving a photovoltaic conversion efficiency of 4.43%. The results provides useful information in investigation and development of stable, low-cost, simple-design, flexible and lightweight DSCs.展开更多
Carbon nitride(CN_x) films supported on fluorine-doped tin oxide(FTO) glass are prepared by radio frequency magnetron sputtering, in which the film thicknesses are 90-100 nm, and the element components in the CNX film...Carbon nitride(CN_x) films supported on fluorine-doped tin oxide(FTO) glass are prepared by radio frequency magnetron sputtering, in which the film thicknesses are 90-100 nm, and the element components in the CNX films are in the range of x = 0.15-0.25. The as-prepared CN_x is for the first time used as counter electrode for dye-sensitized solar cells(DSSCs), and show a preparation-temperature dependent electrochemical performance. X-ray photoelectron spectroscopy(XPS) demonstrates that there is a higher proportion of sp^2 C=C and sp^3 C-N hybridized bonds in CN_x-500(the sample treated at 500 ℃) than in CNX-RT(the sample without a heat treatment). It is proposed that the sp^2 C=C and sp^3 C-N hybridized bonds in the CN_x films are helpful for improving the electrocatalytic activities in DSSCs. Meanwhile, Raman spectra also prove that CN_x-500 has a relatively high graphitization level that means an increasing electrical conductivity. This further explains why the sample after the heat treatment has a higher electrochemical performance in DSSCs. In addition, the as-prepared CN_x counter electrodes have a good light transmittance in the visible light region. The results are meaningful for developing low-cost metal-free transparent counter electrodes for DSSCs.展开更多
We applied the reduced graphene oxide/multi-walled carbon nanotubes/nickel oxide(RGO/MWCNTs/Ni O)nanocomposite as the counter electrode(CE) in dye-sensitized solar cells(DSSCs) on fluorine-doped tin oxide substrates b...We applied the reduced graphene oxide/multi-walled carbon nanotubes/nickel oxide(RGO/MWCNTs/Ni O)nanocomposite as the counter electrode(CE) in dye-sensitized solar cells(DSSCs) on fluorine-doped tin oxide substrates by blade doctor method. Power conversion efficiency(PCE) of 8.13 % was achieved for this DSSCs device, which is higher than that of DSSCs devices using Ni O, RGO, and RGO/Ni O-CE(PCE = 2.71 %, PCE = 6.77 % and PCE = 7.63 %). Also, the fill factor of the DSSCs devices using the RGO/MWCNTs/Ni O-CE was better than that of other CEs. The electron transfer measurement of cyclic voltammetry and electrochemical impedance spectroscopy showed that RGO/MWCNTs/Ni O film could provide fast electron transfer between the CE and the electrolyte, and high electrocatalytic activity for the reduction of triiodide in a CE based on RGO/MWCNTs/Ni O in a DSSC.展开更多
For some specific catalytic reaction, how to construct active sites on two dimensional materials is of great scientific significance. Dye-sensitized solar cells(DSCs) can be viewed as one representative photovoltaics ...For some specific catalytic reaction, how to construct active sites on two dimensional materials is of great scientific significance. Dye-sensitized solar cells(DSCs) can be viewed as one representative photovoltaics because in which liquid electrolyte with triiodide/iodide(I_3^-/I^-) as redox couples are involved. In this study, amino-functionalized graphene(AFG) has been designed according to theoretically analyzing iodine reduction reaction(IRR) processes and rationally screening the volcanic plot. Then, such AFG has been successfully synthesized by a simple hydrothermal method and shows high electrocatalytic activity towards IRR when serving as counter electrode in DSCs. Finally, a high conversion efficiency of 7.39% by AFG-based DSCs was obtained, which is close to that using Pt as counter electrode.展开更多
We explore a simple and eco-friendly approach for preparing CZTS powders and a screen-printing process for Cu_2ZnSn(S,Se)_4(CZTSSe) counter electrodes(CEs) in dye-sensitized solar cells(DSCs). Cu_2ZnSnS_4(CZTS) nanopa...We explore a simple and eco-friendly approach for preparing CZTS powders and a screen-printing process for Cu_2ZnSn(S,Se)_4(CZTSSe) counter electrodes(CEs) in dye-sensitized solar cells(DSCs). Cu_2ZnSnS_4(CZTS) nanoparticles have been synthesized via a hydrazine-free solvothermal approach without the assistance of organic ligands. CZTS has been prepared by directly drop-casting the CZTS ink on the cleaned FTO glass, while CZTSSe CEs have been fabricated by screen-printing CZTS pastes, followed by post selenization using Se vapor obtained from elemental Se pellets. The crystal structure, composition and morphology of the as-deposited CZTS nanoparticles and CZTSSe electrodes are characterized by X-ray diffractometer, energy dispersive spectrometer, field emission scanning electron microscopy and transmission electron microscopy.The electrochemical properties of CZTS, CZTSSe and Pt CE based DSCs are examined and analyzed by electrochemical impedance spectroscopy. The prepared CZTS and CZTSSe CEs exhibit a cellular structure with high porosity. DSCs fabricated with CZTSSe CEs achieve a power conversion efficiency of 5.75% under AM 1.5 G illumination with an intensity of 100 m W/cm^2, which is higher than that(3.22%) of the cell using the CZTS CE. The results demonstrate that the CZTSSe CE possesses good electrocatalytic activity for the reduction of charge carriers in electrolyte. The comprehensive CZTSSe CE process is cheap and scalable. It can make large-scale electro-catalytic film fabrication cost competitive for both energy harvesting and storage applications.展开更多
A facile template-free in situ self-activation approach for the multiple active components synergistically driven porous carbon was presented via a feasible annealing process.The biomass-derived carbon without additio...A facile template-free in situ self-activation approach for the multiple active components synergistically driven porous carbon was presented via a feasible annealing process.The biomass-derived carbon without additional activation reagents was fabricated using K-rich pomelo peel(PP)as the carbon source,which possesses a high electric conductivity where abundant functional hetero-metal atoms are doped into the carbon framework that playing the role of catalytic graphitization.The K^+that exists within the biomass can induce self-activation during pyrolysis apart from the activating gases during the pyrolysis process.The resulting electrocatalyst of PP-850(PP was pyrolyzed at 850°C in an N_2atmosphere)with abundant heteroatoms possesses a higher power conversion efficiency(PCE)of 7.81%as the counter electrode(CE)of dye-sensitized solar cells(DSCs)compared with the CEs calcinated at other temperatures and a similar PCE with Pt counterpart(8.24%)based on the liquid I_3^-/I^-electrolyte.The better electrocatalytic performance is attributed to the synergistic effect between self-activation and the co-doping of nitrogen,sulfur and phosphorus all together in a carbon matrix.Due to the feasibility of large-scale production,rich heteroatom doping,the PP-derived carbon,which simplifies the procedure and decreases the cost,has a potential application for an alternative electrocatalyst for high-performance photovoltaic devices.展开更多
Commercial application of the dye-sensitized solar cells(DSCs) depends on great improvement of the power conversion efficiency and reduction of the fabrication cost. Generally, developing low cost counter electrode ca...Commercial application of the dye-sensitized solar cells(DSCs) depends on great improvement of the power conversion efficiency and reduction of the fabrication cost. Generally, developing low cost counter electrode catalysts to replace the expensive Pt counter electrode is a feasible path to reduce the production cost of DSCs. In this review article, we summarize the recent progress on the transition metal compound based counter electrode catalysts containing carbides, nitrides, oxides, sulfides, phosphide, selenides, borides, silicide, and telluride toward the regeneration of the traditional iodide redox couple.Moreover, the benefits and drawbacks of each kind of CE catalyst are discussed and the research directions to design new counter electrode catalysts in future research are also proposed.展开更多
The effect of transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)) on the chemical synthesis of polyaniline(PANI) used as a platinum-free counter electrode(CE) in dye-sensitized solar cells(DSSCs) was investi...The effect of transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)) on the chemical synthesis of polyaniline(PANI) used as a platinum-free counter electrode(CE) in dye-sensitized solar cells(DSSCs) was investigated.PANI was synthesized by co-polymerization of aniline in the presence of different transition metal ions by using potassium dichromate in acidic medium. It was found that the ion doping of PANI showed a certain catalytic activity for the regeneration of traditional iodide/triiodide(I^-/I_3^-) redox couples. The power conversion efficiency(η) of PANI CEs doped with Mn^(2+),Ni^(2+),Co^(2+) (4.41%, 2.36% and 2.10%, respectively) were higher than 1.94%, the value measured for PANI CE without doping. Doping with Cu^(2+)decreased the power conversion efficiency of PANI CE(PANI-Cu^(2+) η = 1.41%). The electrical properties of the PANI, PANI-Ni^(2+), PANI-Co^(2+),PANI-Mn^(2+) and PANI-Cu^(2+) were studied by cyclic voltammetry(CV), impedance(EIS), and Tafel polarization curve. The experimental results confirmed that PANI was affected by the doping of different transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)). These results indicate a potential application of ion doped PANI as counter electrode in cost-effective DSSCs.展开更多
Unique ZnS nanobuns decorated with reduced graphene oxide(RGO) was synthesized and found to exhibit a synergetic effect as a highly efficient and low-cost counter electrode(CE) in dye-sensitized solar cells(DSCs). Usi...Unique ZnS nanobuns decorated with reduced graphene oxide(RGO) was synthesized and found to exhibit a synergetic effect as a highly efficient and low-cost counter electrode(CE) in dye-sensitized solar cells(DSCs). Using this ZnS-RGO CE, a power conversion efficiency(PCE) of 7.03% was achieved. This value was 53% and 41% higher than those of pure ZnS and RGO CEs, respectively. The ZnS-RGO nanocomposite is indeed an efficient and cost-effective Pt-like alternative for iodine reduction reaction.展开更多
Development of cost-effective and robust counter electrodes(CEs) is a persistent objective for highefficiency dye-sensitized solar cells(DSSCs). To achieve this goal, we present here the hydrothermal synthesis of well...Development of cost-effective and robust counter electrodes(CEs) is a persistent objective for highefficiency dye-sensitized solar cells(DSSCs). To achieve this goal, we present here the hydrothermal synthesis of well-aligned Ni Pt alloy CEs, which is templated by ZnO nanowires and nanosheets. The preliminary results demonstrate that Ni Pt alloy electrodes are featured by increased charge-transfer processes and electrocatalytic activity in comparison with expensive Pt CE, yielding power conversion efficiencies of 8.29% and 7.41% in corresponding DSSCs with Ni Pt nanowire and nanosheet alloy CEs, respectively. Additionally, the Ni Pt alloy CEs also display extraordinary dissolution-resistant ability when suffering longterm utilization in liquid-junction DSSCs.展开更多
Hierarchical porous carbon is prepared by a combination of self-organization and chemical activation and explored as counter electrode for dye-sensitized solar cells.Pore structure analysis shows that micropores gener...Hierarchical porous carbon is prepared by a combination of self-organization and chemical activation and explored as counter electrode for dye-sensitized solar cells.Pore structure analysis shows that micropores generated within the mesopore wall and the pristine mesopore structure of mesoporous carbon are preserved during KOH activation.Electrochemical impedance spectroscopy studies demonstrate a relatively high electrocatalytic activity of hierarchical porous carbon electrode for triiodide reduction,as compared with a pristine mesoporous carbon electrode.This enhanced electrocatalytic activity is beneficial for improving the photovoltaic performance of dyesensitized solar cells.The overall conversion efficiency of dye-sensitized solar cells with the hierarchical porous carbon electrode increased by 11.5%compared with that of the cell with a pristine mesoporous carbon electrode.展开更多
In order to search for the high efficiency and low sheet resistance counter electrode in dye-sensitized solar cell, we used Ti plate as the conducting substrate to prepare the counter electrode by thermal decompositio...In order to search for the high efficiency and low sheet resistance counter electrode in dye-sensitized solar cell, we used Ti plate as the conducting substrate to prepare the counter electrode by thermal decomposition of H2PtCl6. Ti plate counter electrode shows low sheet resistance, good reflecting performance and matching kinetics. The dye-sensitized solar cell with the Ti plate counter electrode shows better photovoltaic performance than that of the cell with the fluorine-doped tin oxide-coated glass counter electrode.展开更多
A dye-sensitized nanocrystalline TiO 2 solar cell(DYSC) was assembled, of which counter electrode was modified already by platinum, nickel and carbon. It was found that the DYSC had better photoelectric performance wh...A dye-sensitized nanocrystalline TiO 2 solar cell(DYSC) was assembled, of which counter electrode was modified already by platinum, nickel and carbon. It was found that the DYSC had better photoelectric performance when the electrode was modified by platinum than by nickel and carbon. The influence of the incidence light wavelength on the incidence monochromatic photoelectric conversion efficiency(IPCE) was investigated. The result shows that the IPCE mainly depends on the short-circuit current density(I SC) of a DYSC, and the IPCE reaches 48.32% under the irradiation with the wavelength of 560 nm when the counter electrode of a DYSC was modified by platinum. The influence of incident light intensity on the photoelectric properties of a DYSC was also investigated. It was found that the I SC and open-circuit voltage(V OC) increased and the fill factor(f f) of the DYSC decreased with the increase of the incident light intensity.展开更多
To find a novel counter electrode(CE)material for quantum dot-sensitized solar cells(QDSSCs),pompon-like NiCo_(2)O_(4) nanospheres are synthesized by a facile solvothermal and post-calcination method and we attempt to...To find a novel counter electrode(CE)material for quantum dot-sensitized solar cells(QDSSCs),pompon-like NiCo_(2)O_(4) nanospheres are synthesized by a facile solvothermal and post-calcination method and we attempt to apply it as a CE material for QDS SC.The catalytic performance of NiCo_(2)O_(4) counter electrode is investigated in detail through electrochemical impedance spectroscopy,Tafel test and cyclic voltammetry.The catalytic activity of NiCo_(2)O_(4) CE is superior to that of nanoflower-like Cu2S CE and traditional Cu2S/brass CE,which is mainly attributed to the large specific surface area,outstanding electrical conductivity of bimetallic oxides and the synergistic promotion effect of metals with different valence states.Under standard sunlight(air mass AM 1.5G 100 mW·cm^(-2)),the CdS/CdSe/ZnS-sensitized solar cell assembled with NiCo_(2)O_(4) CE achieved a photoelectric conversion efficiency of 5.55%,with a short current density of 22.49 mA·cm^(-2),an open circuit voltage of 0.574 V,and a fill factor of 0.43,which is slightly higher than the QDSSCs with nanoflower-like Cu_(2)S CE(4.75%)and traditional Cu_(2)S/brass CE(4.69%).This research provides ideas for discovering innovative and efficient CE materials for QDSSCs.展开更多
Damage to the spinal cord disrupts the electrically active nerve cells which normally transmit afferent and efferent signals,resulting in loss of motor,sensory,and autonomic functions.Potential treatments for spinal c...Damage to the spinal cord disrupts the electrically active nerve cells which normally transmit afferent and efferent signals,resulting in loss of motor,sensory,and autonomic functions.Potential treatments for spinal cord injury utilizing implanted spinal electrodes can be broadly classified into three different categories.The first of these approaches is“spinal stimulation”where electrodes,usually positioned above the level of injury,provide electrical stimulation to target and disrupt pain signals before they reach the brain.The second approach uses“activity-dependent neuro-technologies”,in which electrodes positioned below the level of injury initiate a complex spatiotemporal pattern of stimulation at the lumbar spinal cord to generate a walking gait in the limbs(Minev et al.,2015;Wagner et al.,2018).展开更多
Black phosphorus with a superior theoretical capacity(2596 mAh g^(-1))and high conductivity is regarded as one of the powerful candidates for lithium-ion battery(LIB)anode materials,whereas the severe volume expansion...Black phosphorus with a superior theoretical capacity(2596 mAh g^(-1))and high conductivity is regarded as one of the powerful candidates for lithium-ion battery(LIB)anode materials,whereas the severe volume expansion and sluggish kinetics still impede its applications in LIBs.By contrast,the exfoliated two-dimensional phosphorene owns negligible volume variation,and its intrinsic piezoelectricity is considered to be beneficial to the Li-ion transfer kinetics,while its positive influence has not been discussed yet.Herein,a phosphorene/MXene heterostructure-textured nanopiezocomposite is proposed with even phosphorene distribution and enhanced piezo-electrochemical coupling as an applicable free-standing asymmetric membrane electrode beyond the skin effect for enhanced Li-ion storage.The experimental and simulation analysis reveals that the embedded phosphorene nanosheets not only provide abundant active sites for Li-ions,but also endow the nanocomposite with favorable piezoelectricity,thus promoting the Li-ion transfer kinetics by generating the piezoelectric field serving as an extra accelerator.By waltzing with the MXene framework,the optimized electrode exhibits enhanced kinetics and stability,achieving stable cycling performances for 1,000 cycles at 2 A g^(-1),and delivering a high reversible capacity of 524 m Ah g^(-1)at-20℃,indicating the positive influence of the structural merits of self-assembled nanopiezocomposites on promoting stability and kinetics.展开更多
Sluggish storage kinetics is considered as the main bottleneck of cathode materials for fast-charging aqueous zinc-ion batteries(AZIBs).In this report,we propose a novel in-situ self-etching strategy to unlock the Pal...Sluggish storage kinetics is considered as the main bottleneck of cathode materials for fast-charging aqueous zinc-ion batteries(AZIBs).In this report,we propose a novel in-situ self-etching strategy to unlock the Palm tree-like vanadium oxide/carbon nanofiber membrane(P-VO/C)as a robust freestanding electrode.Comprehensive investigations including the finite element simulation,in-situ X-ray diffraction,and in-situ electrochemical impedance spectroscopy disclosed it an electrochemically induced phase transformation mechanism from VO to layered Zn_(x)V_(2)O_5·nH_(2)O,as well as superior storage kinetics with ultrahigh pseudocapacitive contribution.As demonstrated,such electrode can remain a specific capacity of 285 mA h g^(-1)after 100 cycles at 1 A g^(-1),144.4 mA h g^(-1)after 1500 cycles at 30 A g^(-1),and even 97 mA h g^(-1)after 3000 cycles at 60 A g^(-1),respectively.Unexpectedly,an impressive power density of 78.9 kW kg^(-1)at the super-high current density of 100 A g^(-1)also can be achieved.Such design concept of in-situ self-etching free-standing electrode can provide a brand-new insight into extending the pseudocapacitive storage limit,so as to promote the development of high-power energy storage devices including but not limited to AZIBs.展开更多
基金supported by National Natural Science Foundation of China(No.10774046)Shanghai Municipal Science&Technology Committee(No.09JC1404600+1 种基金No.0852nm06100 and No.08230705400)Singapore Ministry of Education innovation fund(MOE IF Funding MOE2008-IF-1-016)
文摘A flexible counter electrode(CE) for dye-sensitized solar cells(DSCs) has been fabricated using a micro-porous polyvinylidene fluoride membrane as support media and sputtered Pt as the catalytic material.Non-conventional structure DSCs have been developed by the fabricated CEs. The Pt metal was sputtered onto one surface of the membrane as the catalytic material. DSCs were assembled by attaching the Ti O2 electrode to the membrane surface without Pt coating. The membrane was with cylindrical pore geometry. It served not only as a substrate for the CE but also as a spacer for the DSC. The fabricated DSC with the flexible membrane CE showed higher photocurrent density than the conventional sandwich devices based on chemically deposited Pt/FTO glass, achieving a photovoltaic conversion efficiency of 4.43%. The results provides useful information in investigation and development of stable, low-cost, simple-design, flexible and lightweight DSCs.
基金Financial support from the 973 Program (2015CB251100)NSFC (51001063)MOE Innovation Team (IRT13022)
文摘Carbon nitride(CN_x) films supported on fluorine-doped tin oxide(FTO) glass are prepared by radio frequency magnetron sputtering, in which the film thicknesses are 90-100 nm, and the element components in the CNX films are in the range of x = 0.15-0.25. The as-prepared CN_x is for the first time used as counter electrode for dye-sensitized solar cells(DSSCs), and show a preparation-temperature dependent electrochemical performance. X-ray photoelectron spectroscopy(XPS) demonstrates that there is a higher proportion of sp^2 C=C and sp^3 C-N hybridized bonds in CN_x-500(the sample treated at 500 ℃) than in CNX-RT(the sample without a heat treatment). It is proposed that the sp^2 C=C and sp^3 C-N hybridized bonds in the CN_x films are helpful for improving the electrocatalytic activities in DSSCs. Meanwhile, Raman spectra also prove that CN_x-500 has a relatively high graphitization level that means an increasing electrical conductivity. This further explains why the sample after the heat treatment has a higher electrochemical performance in DSSCs. In addition, the as-prepared CN_x counter electrodes have a good light transmittance in the visible light region. The results are meaningful for developing low-cost metal-free transparent counter electrodes for DSSCs.
基金supported by the National Basic Research Program(2011CB933300)of Chinathe National Natural Science Foundation of China(11374110,11204093,51371085,and 11304106)
文摘We applied the reduced graphene oxide/multi-walled carbon nanotubes/nickel oxide(RGO/MWCNTs/Ni O)nanocomposite as the counter electrode(CE) in dye-sensitized solar cells(DSSCs) on fluorine-doped tin oxide substrates by blade doctor method. Power conversion efficiency(PCE) of 8.13 % was achieved for this DSSCs device, which is higher than that of DSSCs devices using Ni O, RGO, and RGO/Ni O-CE(PCE = 2.71 %, PCE = 6.77 % and PCE = 7.63 %). Also, the fill factor of the DSSCs devices using the RGO/MWCNTs/Ni O-CE was better than that of other CEs. The electron transfer measurement of cyclic voltammetry and electrochemical impedance spectroscopy showed that RGO/MWCNTs/Ni O film could provide fast electron transfer between the CE and the electrolyte, and high electrocatalytic activity for the reduction of triiodide in a CE based on RGO/MWCNTs/Ni O in a DSSC.
基金Financial support provided by the National Natural Science Foundation of China (Grant No. 51402036, 21373042)International Science & Technology Cooperation Program of China (Grant No. 2013DFA51000)+1 种基金the Fundamental Research Funds for the Central Universities (Grant No. DUT15YQ109)supported by the State Key Laboratory of Fine Chemicals of China
文摘For some specific catalytic reaction, how to construct active sites on two dimensional materials is of great scientific significance. Dye-sensitized solar cells(DSCs) can be viewed as one representative photovoltaics because in which liquid electrolyte with triiodide/iodide(I_3^-/I^-) as redox couples are involved. In this study, amino-functionalized graphene(AFG) has been designed according to theoretically analyzing iodine reduction reaction(IRR) processes and rationally screening the volcanic plot. Then, such AFG has been successfully synthesized by a simple hydrothermal method and shows high electrocatalytic activity towards IRR when serving as counter electrode in DSCs. Finally, a high conversion efficiency of 7.39% by AFG-based DSCs was obtained, which is close to that using Pt as counter electrode.
基金supported by National Natural Science Foundation of China (No. 11274119 and 61275038)Pujiang Talent Program of Shanghai Science and Technology Commission (No. 11PJ1402700)
文摘We explore a simple and eco-friendly approach for preparing CZTS powders and a screen-printing process for Cu_2ZnSn(S,Se)_4(CZTSSe) counter electrodes(CEs) in dye-sensitized solar cells(DSCs). Cu_2ZnSnS_4(CZTS) nanoparticles have been synthesized via a hydrazine-free solvothermal approach without the assistance of organic ligands. CZTS has been prepared by directly drop-casting the CZTS ink on the cleaned FTO glass, while CZTSSe CEs have been fabricated by screen-printing CZTS pastes, followed by post selenization using Se vapor obtained from elemental Se pellets. The crystal structure, composition and morphology of the as-deposited CZTS nanoparticles and CZTSSe electrodes are characterized by X-ray diffractometer, energy dispersive spectrometer, field emission scanning electron microscopy and transmission electron microscopy.The electrochemical properties of CZTS, CZTSSe and Pt CE based DSCs are examined and analyzed by electrochemical impedance spectroscopy. The prepared CZTS and CZTSSe CEs exhibit a cellular structure with high porosity. DSCs fabricated with CZTSSe CEs achieve a power conversion efficiency of 5.75% under AM 1.5 G illumination with an intensity of 100 m W/cm^2, which is higher than that(3.22%) of the cell using the CZTS CE. The results demonstrate that the CZTSSe CE possesses good electrocatalytic activity for the reduction of charge carriers in electrolyte. The comprehensive CZTSSe CE process is cheap and scalable. It can make large-scale electro-catalytic film fabrication cost competitive for both energy harvesting and storage applications.
基金financial assistance from the National Natural Science Foundation of China (Grant nos. 51402036 and 51773025)the International Science & Technology Cooperation Program of China (Grant no. 2013DFA51000)
文摘A facile template-free in situ self-activation approach for the multiple active components synergistically driven porous carbon was presented via a feasible annealing process.The biomass-derived carbon without additional activation reagents was fabricated using K-rich pomelo peel(PP)as the carbon source,which possesses a high electric conductivity where abundant functional hetero-metal atoms are doped into the carbon framework that playing the role of catalytic graphitization.The K^+that exists within the biomass can induce self-activation during pyrolysis apart from the activating gases during the pyrolysis process.The resulting electrocatalyst of PP-850(PP was pyrolyzed at 850°C in an N_2atmosphere)with abundant heteroatoms possesses a higher power conversion efficiency(PCE)of 7.81%as the counter electrode(CE)of dye-sensitized solar cells(DSCs)compared with the CEs calcinated at other temperatures and a similar PCE with Pt counterpart(8.24%)based on the liquid I_3^-/I^-electrolyte.The better electrocatalytic performance is attributed to the synergistic effect between self-activation and the co-doping of nitrogen,sulfur and phosphorus all together in a carbon matrix.Due to the feasibility of large-scale production,rich heteroatom doping,the PP-derived carbon,which simplifies the procedure and decreases the cost,has a potential application for an alternative electrocatalyst for high-performance photovoltaic devices.
基金the support of the National Natural Science Foundation of China under grant No. 20673141 the National Basic Research Program of China （973 Program） under grant No. 2006CB202606 the National High Technology Research and Development Program （863 Program） under grant No. 2006AA03Z341 and the 100-Talents Project of Chinese Academy of Sciences.
文摘敏化染料的太阳能电池(DSC ) 在于有 nanoparticulated 半导体， sensitizers，电解质和相反的电极(CE ) 的几 differentmaterials:photoanodes 的联合。每材料为 CE 的主要功能是把电子转移到氧化还原作用电解质和 regenerate 碘化物离子的太阳能 intoelectricity.The 的变换执行特定的任务。GE 的工作主要集中于运动表演的研究和传统的 CE 的稳定性改进 DSC 的全面效率，寻求新奇设计概念或新材料。在这评论，发展和研究不同 CE 材料和他们的电气化学的表演进行，并且这些问题被讨论。
基金supported by National Natural Science Foundation of China(21303039)Natural Science Foundation of Hebei Province(B2015205163,B2013205171)+1 种基金Support Program for Hundred Excellent Innovation Talents from the Universities of Hebei Province,(BR2-220)supported by Science Foundation of Hebei Normal University(L2016J02)
文摘Commercial application of the dye-sensitized solar cells(DSCs) depends on great improvement of the power conversion efficiency and reduction of the fabrication cost. Generally, developing low cost counter electrode catalysts to replace the expensive Pt counter electrode is a feasible path to reduce the production cost of DSCs. In this review article, we summarize the recent progress on the transition metal compound based counter electrode catalysts containing carbides, nitrides, oxides, sulfides, phosphide, selenides, borides, silicide, and telluride toward the regeneration of the traditional iodide redox couple.Moreover, the benefits and drawbacks of each kind of CE catalyst are discussed and the research directions to design new counter electrode catalysts in future research are also proposed.
基金Supported by the National Natural Science Foundation of China(21473048,21303039)the Natural Science Foundation of Hebei Province(B2016205161,B2015205163)the 2015 Hebei Province Undergraduate Training Programs for Innovation and Entrepreneurship
文摘The effect of transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)) on the chemical synthesis of polyaniline(PANI) used as a platinum-free counter electrode(CE) in dye-sensitized solar cells(DSSCs) was investigated.PANI was synthesized by co-polymerization of aniline in the presence of different transition metal ions by using potassium dichromate in acidic medium. It was found that the ion doping of PANI showed a certain catalytic activity for the regeneration of traditional iodide/triiodide(I^-/I_3^-) redox couples. The power conversion efficiency(η) of PANI CEs doped with Mn^(2+),Ni^(2+),Co^(2+) (4.41%, 2.36% and 2.10%, respectively) were higher than 1.94%, the value measured for PANI CE without doping. Doping with Cu^(2+)decreased the power conversion efficiency of PANI CE(PANI-Cu^(2+) η = 1.41%). The electrical properties of the PANI, PANI-Ni^(2+), PANI-Co^(2+),PANI-Mn^(2+) and PANI-Cu^(2+) were studied by cyclic voltammetry(CV), impedance(EIS), and Tafel polarization curve. The experimental results confirmed that PANI was affected by the doping of different transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)). These results indicate a potential application of ion doped PANI as counter electrode in cost-effective DSSCs.
基金supported by the National Nature Science Foundation of China(No.20975012)the 111 Project (B07012)+1 种基金the Major State Basic Research Development Program(No.2006CB202605)the High-Tech Research and Development Program of China(No.2007AA05Z439)
文摘一个新奇低温度方法被用来相反准备 mesoporous 碳(MC ) 做铟的锡氧化物上的电极(CE ) 为灵活敏化染料的太阳能电池(DSSC ) 的涂的聚乙烯 naphthalate (ITO 国际笔会) 。有碳装载 280 渭 g 厘米的获得的灵活 MC CE ? 2 被 SEM， XRD 和电气化学的阻抗描绘。与准备灵活 MC CE 制作的 DSSC 的 light-to-electricity 变换效率基于 decomposited 磅 CE 是 DSSC 的中的 86% 个。
基金supported by the National Natural Science Foundation of China(Grant No.51172102,51302125 and 51303076)
文摘Unique ZnS nanobuns decorated with reduced graphene oxide(RGO) was synthesized and found to exhibit a synergetic effect as a highly efficient and low-cost counter electrode(CE) in dye-sensitized solar cells(DSCs). Using this ZnS-RGO CE, a power conversion efficiency(PCE) of 7.03% was achieved. This value was 53% and 41% higher than those of pure ZnS and RGO CEs, respectively. The ZnS-RGO nanocomposite is indeed an efficient and cost-effective Pt-like alternative for iodine reduction reaction.
基金financial supports from the National Natural Science Foundation of China(21503202,61604143,51362031)Shandong Provincial Natural Science Foundation(JQ201714)and Fundamental Research Funds for the Central Universities(201762018)
文摘Development of cost-effective and robust counter electrodes(CEs) is a persistent objective for highefficiency dye-sensitized solar cells(DSSCs). To achieve this goal, we present here the hydrothermal synthesis of well-aligned Ni Pt alloy CEs, which is templated by ZnO nanowires and nanosheets. The preliminary results demonstrate that Ni Pt alloy electrodes are featured by increased charge-transfer processes and electrocatalytic activity in comparison with expensive Pt CE, yielding power conversion efficiencies of 8.29% and 7.41% in corresponding DSSCs with Ni Pt nanowire and nanosheet alloy CEs, respectively. Additionally, the Ni Pt alloy CEs also display extraordinary dissolution-resistant ability when suffering longterm utilization in liquid-junction DSSCs.
基金Supported by the National Natural Science Foundation of China under Grant No 20773082Shandong Natural Science Foundation under Grant No ZR2010BM038.
文摘Hierarchical porous carbon is prepared by a combination of self-organization and chemical activation and explored as counter electrode for dye-sensitized solar cells.Pore structure analysis shows that micropores generated within the mesopore wall and the pristine mesopore structure of mesoporous carbon are preserved during KOH activation.Electrochemical impedance spectroscopy studies demonstrate a relatively high electrocatalytic activity of hierarchical porous carbon electrode for triiodide reduction,as compared with a pristine mesoporous carbon electrode.This enhanced electrocatalytic activity is beneficial for improving the photovoltaic performance of dyesensitized solar cells.The overall conversion efficiency of dye-sensitized solar cells with the hierarchical porous carbon electrode increased by 11.5%compared with that of the cell with a pristine mesoporous carbon electrode.
文摘In order to search for the high efficiency and low sheet resistance counter electrode in dye-sensitized solar cell, we used Ti plate as the conducting substrate to prepare the counter electrode by thermal decomposition of H2PtCl6. Ti plate counter electrode shows low sheet resistance, good reflecting performance and matching kinetics. The dye-sensitized solar cell with the Ti plate counter electrode shows better photovoltaic performance than that of the cell with the fluorine-doped tin oxide-coated glass counter electrode.
基金Supported by the National Natural Science Foundation of China(No. 5 0 0 82 0 0 3,5 0 372 0 2 2 ) and the Natural ScienceFoundation of Fujian Province,China(No. 2 0 0 1I0 0 6,E0 2 10 0 2 3)
文摘A dye-sensitized nanocrystalline TiO 2 solar cell(DYSC) was assembled, of which counter electrode was modified already by platinum, nickel and carbon. It was found that the DYSC had better photoelectric performance when the electrode was modified by platinum than by nickel and carbon. The influence of the incidence light wavelength on the incidence monochromatic photoelectric conversion efficiency(IPCE) was investigated. The result shows that the IPCE mainly depends on the short-circuit current density(I SC) of a DYSC, and the IPCE reaches 48.32% under the irradiation with the wavelength of 560 nm when the counter electrode of a DYSC was modified by platinum. The influence of incident light intensity on the photoelectric properties of a DYSC was also investigated. It was found that the I SC and open-circuit voltage(V OC) increased and the fill factor(f f) of the DYSC decreased with the increase of the incident light intensity.
基金financially supported by the Natural Science Foundation of China(Grant Nos.22071018 and 21671035)。
文摘To find a novel counter electrode(CE)material for quantum dot-sensitized solar cells(QDSSCs),pompon-like NiCo_(2)O_(4) nanospheres are synthesized by a facile solvothermal and post-calcination method and we attempt to apply it as a CE material for QDS SC.The catalytic performance of NiCo_(2)O_(4) counter electrode is investigated in detail through electrochemical impedance spectroscopy,Tafel test and cyclic voltammetry.The catalytic activity of NiCo_(2)O_(4) CE is superior to that of nanoflower-like Cu2S CE and traditional Cu2S/brass CE,which is mainly attributed to the large specific surface area,outstanding electrical conductivity of bimetallic oxides and the synergistic promotion effect of metals with different valence states.Under standard sunlight(air mass AM 1.5G 100 mW·cm^(-2)),the CdS/CdSe/ZnS-sensitized solar cell assembled with NiCo_(2)O_(4) CE achieved a photoelectric conversion efficiency of 5.55%,with a short current density of 22.49 mA·cm^(-2),an open circuit voltage of 0.574 V,and a fill factor of 0.43,which is slightly higher than the QDSSCs with nanoflower-like Cu_(2)S CE(4.75%)and traditional Cu_(2)S/brass CE(4.69%).This research provides ideas for discovering innovative and efficient CE materials for QDSSCs.
基金supported by the CatWalk Spinal Cord Injury Trust and the Health Research Council of New Zealand(Project grant and HRC/Catwalk Partnership 19/895)(to DS).
文摘Damage to the spinal cord disrupts the electrically active nerve cells which normally transmit afferent and efferent signals,resulting in loss of motor,sensory,and autonomic functions.Potential treatments for spinal cord injury utilizing implanted spinal electrodes can be broadly classified into three different categories.The first of these approaches is“spinal stimulation”where electrodes,usually positioned above the level of injury,provide electrical stimulation to target and disrupt pain signals before they reach the brain.The second approach uses“activity-dependent neuro-technologies”,in which electrodes positioned below the level of injury initiate a complex spatiotemporal pattern of stimulation at the lumbar spinal cord to generate a walking gait in the limbs(Minev et al.,2015;Wagner et al.,2018).
基金financially supported by the National Key Research and Development Program of China(No.2017YFB1002900)the National Natural Science Foundation of China(No.51661145021)+5 种基金the Key Natural Science Program of Jiangsu Province(Nos.BE2022118,BE2021643 and BE2016772)the Traction Project of Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province(No.Q816000217)the Scholarship from Key Laboratory of Modern Optical Technologies of Ministry of Education of Chinathe Priority Academic Program Development(PAPD)of Jiangsu Higher Education InstitutionsChina Prosperity Green Industry Foundation of Ministry of Industry and Information Technologysupported by the open project of synchrotron radiation characterization of chain oriented/stacked polar topology and energy modulation of supramolecules(No.2100982)。
文摘Black phosphorus with a superior theoretical capacity(2596 mAh g^(-1))and high conductivity is regarded as one of the powerful candidates for lithium-ion battery(LIB)anode materials,whereas the severe volume expansion and sluggish kinetics still impede its applications in LIBs.By contrast,the exfoliated two-dimensional phosphorene owns negligible volume variation,and its intrinsic piezoelectricity is considered to be beneficial to the Li-ion transfer kinetics,while its positive influence has not been discussed yet.Herein,a phosphorene/MXene heterostructure-textured nanopiezocomposite is proposed with even phosphorene distribution and enhanced piezo-electrochemical coupling as an applicable free-standing asymmetric membrane electrode beyond the skin effect for enhanced Li-ion storage.The experimental and simulation analysis reveals that the embedded phosphorene nanosheets not only provide abundant active sites for Li-ions,but also endow the nanocomposite with favorable piezoelectricity,thus promoting the Li-ion transfer kinetics by generating the piezoelectric field serving as an extra accelerator.By waltzing with the MXene framework,the optimized electrode exhibits enhanced kinetics and stability,achieving stable cycling performances for 1,000 cycles at 2 A g^(-1),and delivering a high reversible capacity of 524 m Ah g^(-1)at-20℃,indicating the positive influence of the structural merits of self-assembled nanopiezocomposites on promoting stability and kinetics.
基金financially supported by the Shenzhen Science and Technology Program (JCYJ20200109105805902,JCYJ20220818095805012)the National Natural Science Foundation of China (22208221,22178221,42377487)+2 种基金the Scientific and Technological Plan of Guangdong Province (2019B090905005,2019B090911004)the Natural Science Foundation of Guangdong Province (2021A1515110751)the Guangdong Basic and Applied Basic Research Foundation (2022A1515110477,2021B1515120004)。
文摘Sluggish storage kinetics is considered as the main bottleneck of cathode materials for fast-charging aqueous zinc-ion batteries(AZIBs).In this report,we propose a novel in-situ self-etching strategy to unlock the Palm tree-like vanadium oxide/carbon nanofiber membrane(P-VO/C)as a robust freestanding electrode.Comprehensive investigations including the finite element simulation,in-situ X-ray diffraction,and in-situ electrochemical impedance spectroscopy disclosed it an electrochemically induced phase transformation mechanism from VO to layered Zn_(x)V_(2)O_5·nH_(2)O,as well as superior storage kinetics with ultrahigh pseudocapacitive contribution.As demonstrated,such electrode can remain a specific capacity of 285 mA h g^(-1)after 100 cycles at 1 A g^(-1),144.4 mA h g^(-1)after 1500 cycles at 30 A g^(-1),and even 97 mA h g^(-1)after 3000 cycles at 60 A g^(-1),respectively.Unexpectedly,an impressive power density of 78.9 kW kg^(-1)at the super-high current density of 100 A g^(-1)also can be achieved.Such design concept of in-situ self-etching free-standing electrode can provide a brand-new insight into extending the pseudocapacitive storage limit,so as to promote the development of high-power energy storage devices including but not limited to AZIBs.
