Although the synthesis of novel nanostructured metal sulfides has been well established,further size-controllable optimization is still valuable to enhance their performance for various applications.Herein,a self-temp...Although the synthesis of novel nanostructured metal sulfides has been well established,further size-controllable optimization is still valuable to enhance their performance for various applications.Herein,a self-template method to size-controllably synthesize the hollow NiCo2S4 nanospheres is reported.Uniformly monodisperse Ni Co precursors with diameter widely ranging from 97 to 550 nm are controllably synthesized and subsequently transformed into hollow NiCo2S4 nanospheres through in situ sulfidation.Smaller nanoparticles’diameter results in the hollow NiCo2S4 nanospheres larger surface area and thinner shell thickness and hence provides much more electrochemical active sites as well as facilitate the ion and electron transfer.Consequently,the hollow NiCo2S4 nanospheres—used as the electrode materials in supercapacitors—achieve 19%enhancement of specific capacity from 484.8 to 575.1 C g-1 through lowering the 42.5%diameter of hollow NiCo2S4 nanospheres from 407 to 234 nm.Moreover,the hollow NiCo2S4 nanospheres with 234 nm diameter exhibit superior rate capacity indicated by 49%capacity retention from 1 to 50 A g-1 and excellent cycling stability(77%after 2000 cycles).Furthermore,this method is a potentially general strategy in the size-controllable synthesis of the metal sulfides hollow nanostructures and results in the remarkable electrochemical applications.展开更多
Monodispersed nitrogen-doped carbon nanospheres with tunable particle size(100-230 nm)were synthesized via self-polymerization of biochemical dopamine in the presence of hexamethylenetetramine as a buffer and F127 as ...Monodispersed nitrogen-doped carbon nanospheres with tunable particle size(100-230 nm)were synthesized via self-polymerization of biochemical dopamine in the presence of hexamethylenetetramine as a buffer and F127 as a size controlling agent.Hexamethylenetetramine can mildly release NH3,which in turn initiates the polymerization reaction of dopamine.The carbon nanospheres obtained exhibited a significant energy storage capability of 265 F·g^(-1)at 0.5 A·g^(-1)and high-rate performance of 82%in 6 mol·L^(-1)KOH(20 A·g^(-1)),which could be attributed to the presence of abundant micromesoporous structure,doped nitrogen functional groups and the small particle size.Moreover,the fabricated symmetric supercapacitor device displayed a high stability of 94%after 5000 cycles,revealing the considerable potential of carbon nanospheres as electrode materials for energy storage.展开更多
MoS2 has emerged for catalyzing the hydrogen evolution reaction.Various notable strategies have been developed to downsize the MoS2 particles and expose more active edges.However,the restacking issue,which reduces the...MoS2 has emerged for catalyzing the hydrogen evolution reaction.Various notable strategies have been developed to downsize the MoS2 particles and expose more active edges.However,the restacking issue,which reduces the exposure degree,has rarely been taken into account.Herein,we report on a facile proton-induced fast hydrothermal approach to produce size-controllable MoS2 nanocatalysts and demonstrate that along the varying of sheet sizes,there is a trade-off between the intrinsic catalytic activity(mainly determined by the unsaturated sulfur on the sheet edges)and the active edge accessibility(influenced by the assembly structure).The size-optimized catalyst delivers a high performance of a low overpotential of~200 mV at 10 mA/cm^(2),a Tafel slope of 46.3 mV/dec,and a stable working state,which is comparable to the recent notable works.Our findings will provide a pathway for its large-scale application and enhance the water electrolysis performance.展开更多
A new strategy for the facile synthesis of very stable and mono-dispersed silver （Ag） quantum dots （QDs） is developed by laser fragmentation of bulk Ag in water using polysorbate 80 as a dispersing and stabilizing...A new strategy for the facile synthesis of very stable and mono-dispersed silver （Ag） quantum dots （QDs） is developed by laser fragmentation of bulk Ag in water using polysorbate 80 as a dispersing and stabilizing agent. The surfactant plays an important role in the formation of size-controlled Ag nano-structures. The Ag QDs have excellent photo-stability of ,-500 h and enhanced photoluminescence （PL） at 510 nm. This has significant implications for selective and ultrasensitive PL probes. Based on laser fragmentation in the biocompatible surfactant solution, our results have opened up a novel paradigm to obtain stable metal QDs directly from bulk targets. This is a breakthrough in the toxicity problems that arise from standard chemical fabrication.展开更多
Transition metal dichalcogenide nanodots （NDs） have received considerable interest. We report a facile bottom-up synthetic route for MoS2 NDs by using molybdenum pentachloride and L-cysteine as precursors in oleylam...Transition metal dichalcogenide nanodots （NDs） have received considerable interest. We report a facile bottom-up synthetic route for MoS2 NDs by using molybdenum pentachloride and L-cysteine as precursors in oleylamine. The synthesis of NDs with a narrow size distribution ranging from 2.2 to 5.3 nm, was tailored by controlling the reaction time. Because of its coating characteristics, oleyalmine leads to uniformity and monodispersity of the NDs. Moreover, the NDs synthesized have large specific surface areas providing active sites. Graphene possesses outstanding conductivity. Combining the advantages of the two materials, the 0D/2D material exhibits superior electrochemical performance because of the 2D permeable channels for ion adsorption, energy storage, and conversion. The as-prepared MoS2/rGO （-2.2 nm） showed a stable capacity of 220 mAh.g-1 after 10,000 cycles at the current density of 20 A.g-1. Furthermore, a reversible capacity -140 mAh·g-1 was obtained at a much higher current density of 40 A.g-L Additionally, this composite exhibited superior catalytic performance evidenced by a small overpotential （222 mV） to afford 10 mA.cm-2, and a small Tafel slope （59.8 mV-decade-1） with good acid-stability. The facile approach may pave the way for the preparation of NDs with these nanostructures for numerous applications.展开更多
Biopolymer microbeads present substantial benefits for cell expansion,tissue engineering,and drug release applications.However,a fabrication system capable of producing homogeneous microspheres with high precision and...Biopolymer microbeads present substantial benefits for cell expansion,tissue engineering,and drug release applications.However,a fabrication system capable of producing homogeneous microspheres with high precision and controllability for cell proliferation,passaging,harvesting and downstream application is limited.Therefore,we developed a co-flow microfluidics-based system for the generation of uniform and size-controllable gelatin-based microcarriers(GMs)for mesenchymal stromal cells(MSCs)expansion and tissue engineering.Our evaluation of GMs revealed superior homogeneity and efficiency of cellular attachment,expansion and harvest,and MSCs expanded on GMs exhibited high viability while retaining differentiation multipotency.Optimization of passaging and harvesting protocols was achieved through the addition of blank GMs and treatment with collagenase,respectively.Furthermore,we demonstrated that MSC-loaded GMs were printable and could serve as building blocks for tissue regeneration scaffolds.These results suggested that our platform held promise for the fabrication of uniform GMs with downstream application of MSC culture,expansion and tissue engineering.展开更多
Development of a titanium silicalite-1(TS-1)catalyst with good crystallinity and a four-coordinate Ti framework is critical for efficient catalytic oxidation reaction under mild conditions.Herein,a size-controlled TS-...Development of a titanium silicalite-1(TS-1)catalyst with good crystallinity and a four-coordinate Ti framework is critical for efficient catalytic oxidation reaction under mild conditions.Herein,a size-controlled TS-1 zeolite(TS-10.1ACh(acetylcholine))was synthesized via steam-assisted crystallization by introducing acetylcholine as a crystal growth modifier in the preparation process,and TS-10.1ACh was also employed in epoxidations of different substrates containing C=C double bonds.The crystalline sizes of the as-synthesized TS-10.1ACh catalysts were controlled with the acetylcholine content,and characterization results showed that the particle sizes of highly crystalline TS-10.1ACh zeolite reached 3.0μm with a good Ti framework.Throughout the synthetic process,the growth rate of the crystals was accelerated by electrostatic interactions between the connected hydroxyl groups of the acetylcholine modifier and the negatively charged skeleton of the pre-zeolites.Furthermore,the TS-10.1ACh catalyst demonstrated maximum catalytic activity,good selectivity and high stability during epoxidation of allyl chloride.Importantly,the TS-10.1ACh catalyst was also highly versatile and effective with different unsaturated substrates.These findings may provide novel,easily separable and large TS-1 catalysts for efficient and clean industrial epoxidations of C=C double bonds.展开更多
Rational designing and controlling of nanostructures is a key factor in realizing appropriate properties required for the high-performance energy fields. In the present study, hollow Sn O2@C nanoparticles（NPs） with ...Rational designing and controlling of nanostructures is a key factor in realizing appropriate properties required for the high-performance energy fields. In the present study, hollow Sn O2@C nanoparticles（NPs） with a mean size of 50 nm have been synthesized in large-scale via a facile hydrothermal approach.The morphology and composition of as-obtained products were studied by various characterized techniques. As an anode material for lithium ion batteries（LIBs）, the as-prepared hollow Sn O2@C NPs exhibit significant improvement in cycle performances. The discharge capacity of lithium battery is as high as 370 m Ah g 1, and the current density is 3910 m A g 1（5 C） after 573 cycles. Furthermore, the capacity recovers up to 1100 m Ah g 1at the rate performances in which the current density is recovered to 156.4 m A g 1（0.2 C）. Undoubtedly, sub-100 nm Sn O2@C NPs provide significant improvement to the electrochemical performance of LIBs as superior-anode nanomaterials, and this carbon coating strategy can pave the way for developing high-performance LIBs.展开更多
Size-controlled synthesis of two-dimensional(2D)catalysts with low stacking numbers and small nanoflake lengths is crucial for promoting the catalytic performance in diverse heterogeneous catalysis.Herein,we report a ...Size-controlled synthesis of two-dimensional(2D)catalysts with low stacking numbers and small nanoflake lengths is crucial for promoting the catalytic performance in diverse heterogeneous catalysis.Herein,we report a facile and general“surface curvature-confined synthesis”strategy to modulate the slab lengths and stacking numbers of 2D transition metal sulfides by controlling the strain induced by different surface curvature of supports.An efficient NiMo sulfide with shorter slab length(average 3.71 nm),less stacking number(1–2 layers)and more edge active sites is synthesized onto ZSM-5 zeolites with the average size of 100 nm,which shows superior kHDS value of dibenzothiophene(14.05×10^−7 mol/(g·s)),enhanced stability up to 80 h,and high direct desulfurization selectivity(>95%).This design concept is also proved to be generally applicable to modulate the slab lengths and stacking numbers of other 2D catalysts such as MoS2 and WS2 nanoflakes,which shows great potentials for developing more ultrasmall 2D catalysts with controlled sizes and excellent catalytic activities.展开更多
Aluminum nanocrystals(Al NCs)are sustainable plasmonic nanomaterials with unique localized surface plasmonic resonance(LSPR)in the ultraviolet(UV)region.Chemical synthesis of sub-100-nm Al NCs remains a considerable c...Aluminum nanocrystals(Al NCs)are sustainable plasmonic nanomaterials with unique localized surface plasmonic resonance(LSPR)in the ultraviolet(UV)region.Chemical synthesis of sub-100-nm Al NCs remains a considerable challenge due to the lack of effective ligands to control their growth.Here,we describe a precise size-controlled synthesis of small colloidal Al NCs(25–100 nm)with strong and tunable LSPR peak from 250 to 372 nmin the UV spectral region by the use of poly(ethylene oxide)(PEO)as a polydentate surface ligand.展开更多
基金supported by the National Natural Science Foundation of China(No.51602265)the Special Funding of China Postdoctoral Science Foundation(No.2018T110992)the Sichuan Science and Technology Program(No.2018RZ0074)
文摘Although the synthesis of novel nanostructured metal sulfides has been well established,further size-controllable optimization is still valuable to enhance their performance for various applications.Herein,a self-template method to size-controllably synthesize the hollow NiCo2S4 nanospheres is reported.Uniformly monodisperse Ni Co precursors with diameter widely ranging from 97 to 550 nm are controllably synthesized and subsequently transformed into hollow NiCo2S4 nanospheres through in situ sulfidation.Smaller nanoparticles’diameter results in the hollow NiCo2S4 nanospheres larger surface area and thinner shell thickness and hence provides much more electrochemical active sites as well as facilitate the ion and electron transfer.Consequently,the hollow NiCo2S4 nanospheres—used as the electrode materials in supercapacitors—achieve 19%enhancement of specific capacity from 484.8 to 575.1 C g-1 through lowering the 42.5%diameter of hollow NiCo2S4 nanospheres from 407 to 234 nm.Moreover,the hollow NiCo2S4 nanospheres with 234 nm diameter exhibit superior rate capacity indicated by 49%capacity retention from 1 to 50 A g-1 and excellent cycling stability(77%after 2000 cycles).Furthermore,this method is a potentially general strategy in the size-controllable synthesis of the metal sulfides hollow nanostructures and results in the remarkable electrochemical applications.
基金the Natural Science Foundation of Shandong Province(Grant No.ZR2019QEM005),Project of Shandong Province Higher Educational Young Innovative Talent Introduction and Cultivation Team[Environment Function Material Innovation Team].
文摘Monodispersed nitrogen-doped carbon nanospheres with tunable particle size(100-230 nm)were synthesized via self-polymerization of biochemical dopamine in the presence of hexamethylenetetramine as a buffer and F127 as a size controlling agent.Hexamethylenetetramine can mildly release NH3,which in turn initiates the polymerization reaction of dopamine.The carbon nanospheres obtained exhibited a significant energy storage capability of 265 F·g^(-1)at 0.5 A·g^(-1)and high-rate performance of 82%in 6 mol·L^(-1)KOH(20 A·g^(-1)),which could be attributed to the presence of abundant micromesoporous structure,doped nitrogen functional groups and the small particle size.Moreover,the fabricated symmetric supercapacitor device displayed a high stability of 94%after 5000 cycles,revealing the considerable potential of carbon nanospheres as electrode materials for energy storage.
基金supported by the National Natural Science Foundation of China(No.21905206)Shanghai Sail Program(No.19YF1450800)。
文摘MoS2 has emerged for catalyzing the hydrogen evolution reaction.Various notable strategies have been developed to downsize the MoS2 particles and expose more active edges.However,the restacking issue,which reduces the exposure degree,has rarely been taken into account.Herein,we report on a facile proton-induced fast hydrothermal approach to produce size-controllable MoS2 nanocatalysts and demonstrate that along the varying of sheet sizes,there is a trade-off between the intrinsic catalytic activity(mainly determined by the unsaturated sulfur on the sheet edges)and the active edge accessibility(influenced by the assembly structure).The size-optimized catalyst delivers a high performance of a low overpotential of~200 mV at 10 mA/cm^(2),a Tafel slope of 46.3 mV/dec,and a stable working state,which is comparable to the recent notable works.Our findings will provide a pathway for its large-scale application and enhance the water electrolysis performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.11575102,11105085,11275116,and 11375108)the Fundamental Research Funds of Shandong University,China(Grant No.2015JC007)
文摘A new strategy for the facile synthesis of very stable and mono-dispersed silver （Ag） quantum dots （QDs） is developed by laser fragmentation of bulk Ag in water using polysorbate 80 as a dispersing and stabilizing agent. The surfactant plays an important role in the formation of size-controlled Ag nano-structures. The Ag QDs have excellent photo-stability of ,-500 h and enhanced photoluminescence （PL） at 510 nm. This has significant implications for selective and ultrasensitive PL probes. Based on laser fragmentation in the biocompatible surfactant solution, our results have opened up a novel paradigm to obtain stable metal QDs directly from bulk targets. This is a breakthrough in the toxicity problems that arise from standard chemical fabrication.
基金This work was supported by the National Key R＆D Program （No. 2016YFB0901502）, National NaturalScience Foundation of China （Nos. 51231003, 51271094, and 21231005）, Ministry of Education （Nos. B12015 and IRT13R30）, and the Fundamental Research Funds for the Central Universities.
文摘Transition metal dichalcogenide nanodots （NDs） have received considerable interest. We report a facile bottom-up synthetic route for MoS2 NDs by using molybdenum pentachloride and L-cysteine as precursors in oleylamine. The synthesis of NDs with a narrow size distribution ranging from 2.2 to 5.3 nm, was tailored by controlling the reaction time. Because of its coating characteristics, oleyalmine leads to uniformity and monodispersity of the NDs. Moreover, the NDs synthesized have large specific surface areas providing active sites. Graphene possesses outstanding conductivity. Combining the advantages of the two materials, the 0D/2D material exhibits superior electrochemical performance because of the 2D permeable channels for ion adsorption, energy storage, and conversion. The as-prepared MoS2/rGO （-2.2 nm） showed a stable capacity of 220 mAh.g-1 after 10,000 cycles at the current density of 20 A.g-1. Furthermore, a reversible capacity -140 mAh·g-1 was obtained at a much higher current density of 40 A.g-L Additionally, this composite exhibited superior catalytic performance evidenced by a small overpotential （222 mV） to afford 10 mA.cm-2, and a small Tafel slope （59.8 mV-decade-1） with good acid-stability. The facile approach may pave the way for the preparation of NDs with these nanostructures for numerous applications.
基金supported by the National Natural Science Foundation of China(Grant No.52075285)the Applied Basic Research Project of Sichuan Province(Grant No.2021YJ0563).
文摘Biopolymer microbeads present substantial benefits for cell expansion,tissue engineering,and drug release applications.However,a fabrication system capable of producing homogeneous microspheres with high precision and controllability for cell proliferation,passaging,harvesting and downstream application is limited.Therefore,we developed a co-flow microfluidics-based system for the generation of uniform and size-controllable gelatin-based microcarriers(GMs)for mesenchymal stromal cells(MSCs)expansion and tissue engineering.Our evaluation of GMs revealed superior homogeneity and efficiency of cellular attachment,expansion and harvest,and MSCs expanded on GMs exhibited high viability while retaining differentiation multipotency.Optimization of passaging and harvesting protocols was achieved through the addition of blank GMs and treatment with collagenase,respectively.Furthermore,we demonstrated that MSC-loaded GMs were printable and could serve as building blocks for tissue regeneration scaffolds.These results suggested that our platform held promise for the fabrication of uniform GMs with downstream application of MSC culture,expansion and tissue engineering.
基金supported by the financial support from the National Natural Science Foundation of China(Grant Nos.21802055 and 32160537)Jiangxi Provincial Natural Science Foundation(Grant No.20202BABL205013)Jiangxi Provincial Department of Education Foundation(Grant No.GJJ190179).
文摘Development of a titanium silicalite-1(TS-1)catalyst with good crystallinity and a four-coordinate Ti framework is critical for efficient catalytic oxidation reaction under mild conditions.Herein,a size-controlled TS-1 zeolite(TS-10.1ACh(acetylcholine))was synthesized via steam-assisted crystallization by introducing acetylcholine as a crystal growth modifier in the preparation process,and TS-10.1ACh was also employed in epoxidations of different substrates containing C=C double bonds.The crystalline sizes of the as-synthesized TS-10.1ACh catalysts were controlled with the acetylcholine content,and characterization results showed that the particle sizes of highly crystalline TS-10.1ACh zeolite reached 3.0μm with a good Ti framework.Throughout the synthetic process,the growth rate of the crystals was accelerated by electrostatic interactions between the connected hydroxyl groups of the acetylcholine modifier and the negatively charged skeleton of the pre-zeolites.Furthermore,the TS-10.1ACh catalyst demonstrated maximum catalytic activity,good selectivity and high stability during epoxidation of allyl chloride.Importantly,the TS-10.1ACh catalyst was also highly versatile and effective with different unsaturated substrates.These findings may provide novel,easily separable and large TS-1 catalysts for efficient and clean industrial epoxidations of C=C double bonds.
基金the Program for the NSFC (Nos. 51302325, 51201115, 51471121)New Century Excellent Talents in University (No. NCET-12-0553)+4 种基金Program for Shenghua Overseas Talent (No. 1681-7607030005) from Central South UniversityHubei Provincial Natural Science Foundation (No. 2014CFB261)the partial financial support from the Open-End Fund for the Valuable and Precision Instruments of Central South University (No. CSUZC2014032)Fundamental Research Funds for the Central Universities (No. 2042015kf0184)Wuhan University
文摘Rational designing and controlling of nanostructures is a key factor in realizing appropriate properties required for the high-performance energy fields. In the present study, hollow Sn O2@C nanoparticles（NPs） with a mean size of 50 nm have been synthesized in large-scale via a facile hydrothermal approach.The morphology and composition of as-obtained products were studied by various characterized techniques. As an anode material for lithium ion batteries（LIBs）, the as-prepared hollow Sn O2@C NPs exhibit significant improvement in cycle performances. The discharge capacity of lithium battery is as high as 370 m Ah g 1, and the current density is 3910 m A g 1（5 C） after 573 cycles. Furthermore, the capacity recovers up to 1100 m Ah g 1at the rate performances in which the current density is recovered to 156.4 m A g 1（0.2 C）. Undoubtedly, sub-100 nm Sn O2@C NPs provide significant improvement to the electrochemical performance of LIBs as superior-anode nanomaterials, and this carbon coating strategy can pave the way for developing high-performance LIBs.
基金This work was supported by the National Key R&D Program of China(No.2018YFE0201704)the National Natural Science Foundation of China(Nos.21631004,21801069,21571054,and 21901064)+2 种基金the Fundamental Research Funds for Central Universities(Nos.3072019CFJ1502 and RCYJTD201801)the University Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2018013)Heilongjiang Provincial Postdoctoral Science Foundation(No.LBH-Z18232)and the Heilongjiang University Excellent Youth Foundation.
文摘Size-controlled synthesis of two-dimensional(2D)catalysts with low stacking numbers and small nanoflake lengths is crucial for promoting the catalytic performance in diverse heterogeneous catalysis.Herein,we report a facile and general“surface curvature-confined synthesis”strategy to modulate the slab lengths and stacking numbers of 2D transition metal sulfides by controlling the strain induced by different surface curvature of supports.An efficient NiMo sulfide with shorter slab length(average 3.71 nm),less stacking number(1–2 layers)and more edge active sites is synthesized onto ZSM-5 zeolites with the average size of 100 nm,which shows superior kHDS value of dibenzothiophene(14.05×10^−7 mol/(g·s)),enhanced stability up to 80 h,and high direct desulfurization selectivity(>95%).This design concept is also proved to be generally applicable to modulate the slab lengths and stacking numbers of other 2D catalysts such as MoS2 and WS2 nanoflakes,which shows great potentials for developing more ultrasmall 2D catalysts with controlled sizes and excellent catalytic activities.
基金the National Natural Science Foundation of China(21975094,21674042,and 21534004)for financial support.K.L.and T.S.thank the Interdisciplinary Innovation Project of the First Hospital of Jilin University(JDYYJCHX001).
文摘Aluminum nanocrystals(Al NCs)are sustainable plasmonic nanomaterials with unique localized surface plasmonic resonance(LSPR)in the ultraviolet(UV)region.Chemical synthesis of sub-100-nm Al NCs remains a considerable challenge due to the lack of effective ligands to control their growth.Here,we describe a precise size-controlled synthesis of small colloidal Al NCs(25–100 nm)with strong and tunable LSPR peak from 250 to 372 nmin the UV spectral region by the use of poly(ethylene oxide)(PEO)as a polydentate surface ligand.
