Realizing fast and continuous generation of reactive oxygen species(ROSs)via iron-based advanced oxidation processes(AOPs)is significant in the environmental and biological fields.However,current AOPs assisted by co-c...Realizing fast and continuous generation of reactive oxygen species(ROSs)via iron-based advanced oxidation processes(AOPs)is significant in the environmental and biological fields.However,current AOPs assisted by co-catalysts still suffer from the poor mass/electron transfer and non-durable promotion effect,giving rise to the sluggish Fe^(2+)/Fe^(3+)cycle and low dynamic concentration of Fe^(2+)for ROS production.Herein,we present a three-dimensional(3D)macroscale co-catalyst functionalized with molybdenum disulfide(MoS_(2))to achieve ultra-efficient Fe^(2+)regeneration(equilibrium Fe^(2+)ratio of 82.4%)and remarkable stability(more than 20 cycles)via a circulating flow-through process.Unlike the conventional batch-type reactor,experiments and computational fluid dynamics simulations demonstrate that the optimal utilization of the 3D active area under the flow-through mode,initiated by the convectionenhanced mass/charge transfer for Fe^(2+)reduction and then strengthened by MoS_(2)-induced flow rotation for sufficient reactant mixing,is crucial for oxidant activation and subsequent ROS generation.Strikingly,the flow-through co-catalytic system with superwetting capabilities can even tackle the intricate oily wastewater stabilized by different surfactants without the loss of pollutant degradation efficiency.Our findings highlight an innovative co-catalyst system design to expand the applicability of AOPs based technology,especially in large-scale complex wastewater treatment.展开更多
TiO2 nanosheets mainly exposed （001） facet were prepared through a hydrothermal process with HF as the morphology-directing agent. Ru and RuO2 species were loaded by photo-deposition methods to prepare the photocata...TiO2 nanosheets mainly exposed （001） facet were prepared through a hydrothermal process with HF as the morphology-directing agent. Ru and RuO2 species were loaded by photo-deposition methods to prepare the photocatalysts. The structural features of the catalysts were characterized by X-ray di raction, transmission electron microscopy, inductively cou-pled plasma atomic emission spectrum, and H2 Temperature-programmed reduction. The photocatalytic property was studied by the O2 evolution from water oxidation, which was examined with respect to the in uences of Ru contents as well as the oxidation and reduction treatments, suggesting the charge separation effect of the Ru species co-catalysts on di erent facets of TiO2 nanosheets. In contrast to Ru/TiO2 and RuO2/TiO2 with the single deposited co-catalyst, the optimized catalyst 0.5%Ru-1.0%RuO2/TiO2 with dual co-catalysts achieved a much improved catalytic performance, in terms of the synergetic effect of dual co-catalysts and the enhanced charge separation effect.展开更多
Accelerating the separation efficiency of photoexcited electron-hole pairs with the help of highly active co-catalysts has proven to be a promising approach for improving photocatalytic activity. Thus far, the most de...Accelerating the separation efficiency of photoexcited electron-hole pairs with the help of highly active co-catalysts has proven to be a promising approach for improving photocatalytic activity. Thus far, the most developed co-catalysts for semiconductor-based photocatalysis are inorganic materials;the employment of a specific organic molecule as a co-catalyst for photocatalytic hydrogen evolution and pollutant photodegradation is rare and still remains a challenging task. Herein, we report on the use of an organic molecule, oxamide (OA), as a novel co-catalyst to enhance electron- hole separation, photocatalytic H2 evolution, and dye degradation over TiO2 nanosheets. OA-modified TiO2 samples were prepared by a wet chemical route and demonstrated improved light absorption in the visible-light region and more efficient charge transport. The photocatalytic performance of H2 evolution from water splitting and rhodamine B (RhB) degradation for an optimal OA-modified TiO2 photocatalyst reached 2.37 mmol g^–1 h^–1 and 1.43 × 10^-2 min^-1, respectively, which were 2.4 and 3.8 times higher than those of pristine TiO2, respectively. A possible mechanism is proposed, in which the specific π-conjugated structure of OA is suggested to play a key role in the enhancement of the charge transfer and catalytic capability of TiO2. This work may provide advanced insight into the development of a variety of metal-free organic molecules as functional co-catalysts for improved solar-to-fuel conversion and environmental remediation.展开更多
Since their seminal discovery in 2011,two-dimensional(2D)transition metal carbides/nitrides known as MXenes,that constitute a large family of 2D materials,have been targeted toward various applications due to their ou...Since their seminal discovery in 2011,two-dimensional(2D)transition metal carbides/nitrides known as MXenes,that constitute a large family of 2D materials,have been targeted toward various applications due to their outstanding electronic properties.MXenes functioning as co-catalyst in combination with certain photocatalysts have been applied in photocatalytic systems to enhance photogenerated charge separation,suppress rapid charge recombination,and convert solar energy into chemical energy or use it in the degradation of organic compounds.The photocatalytic performance greatly depends on the composition and morphology of the photocatalyst,which,in turn,are determined by the method of preparation used.Here,we review the four different synthesis methods(mechanical mixing,self-assembly,in situ decoration,and oxidation)reported for MXenes in view of their application as co-catalyst in photocatalysis.In addition,the working mechanism for MXenes application in photocatalysis is discussed and an outlook for future research is also provided.展开更多
The biggest challenging issue in photocatalysis is efficient separation of the photoinduced carriers and the aggregation of photoexcited electrons on photocatalyst’s surface.In this paper,we report that double metall...The biggest challenging issue in photocatalysis is efficient separation of the photoinduced carriers and the aggregation of photoexcited electrons on photocatalyst’s surface.In this paper,we report that double metallic co-catalysts Ti3C2 MXene and metallic octahedral(1T)phase tungsten disulfide(WS2)act pathways transferring photoexcited electrons in assisting the photocatalytic H2 evolution.TiO2 nanosheets were in situ grown on highly conductive Ti3C2 MXenes and 1T-WS2 nanoparticles were then uniformly distributed on TiO2@Ti3C2 composite.Thus,a distinctive 1T-WS2@TiO2@Ti3C2 composite with double metallic co-catalysts was achieved,and the content of 1T phase reaches 73%.The photocatalytic H2 evolution performance of 1T-WS2@TiO2@Ti3C2 composite with an optimized 15 wt%WS2 ratio is nearly 50 times higher than that of TiO2 nanosheets because of conductive Ti3C2 MXene and 1T-WS2 resulting in the increase of electron transfer efficiency.Besides,the 1T-WS2 on the surface of TiO2@Ti3C2 composite enhances the Brunauer–Emmett–Teller surface area and boosts the density of active site.展开更多
Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis.However,the biggest challenge...Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis.However,the biggest challenge in photocatalysis is the efficient separation of photo-induced carriers.To this end,we report that the mesoporous TiO_(2)nanoparticles are anchored on highly conductive Ti_(3)C_(2)MXene co-catalyst by electrostatic self-assembly strategy.The constructed mesoporous TiO_(2)/Ti_(3)C_(2)composites display that the mesoporous TiO_(2)nanoparticles are uniformly distributed on the surface of layer structured Ti_(3)C_(2)nanosheets.More importantly,the as-obtained mesoporous TiO_(2)/Ti_(3)C_(2)composites reveal the significantly enhanced light absorption performance,photo-induced carriers separation and transfer ability,thus boosting the photocatalytic activity.The photocatalytic methyl orange degradation efficiency of mesoporous TiO_(2)/Ti_(3)C_(2)composite with an optimized Ti_(3)C_(2)content(3 wt%)can reach 99.6%within 40 min.The capture experiments of active species confirm that the·O_(2)-and·OH play major role in photocatalytic degradation process.Furthermore,the optimized mesoporous TiO_(2)/Ti_(3)C_(2)composite also shows an excellent photocatalytic H2 production rate of 218.85μmol g^(-1)h^(-1),resulting in a 5.6 times activity as compared with the pristine mesoporous TiO_(2)nanoparticles.This study demonstrates that the MXene family materials can be applied as highly efficient noble-metal-free co-catalysts in the field of photocatalysis.展开更多
This paper describes the combinational surface kinetics enhancement and surface states passivation of nickel-borate （Ni-Bi） co-catalyst for a hematite （Fe_2O_3） photoanode. The Ni-Brmodified Fe_2O_3 photoanode exh...This paper describes the combinational surface kinetics enhancement and surface states passivation of nickel-borate （Ni-Bi） co-catalyst for a hematite （Fe_2O_3） photoanode. The Ni-Brmodified Fe_2O_3 photoanode exhibits a cathodic onset potential shift of 230 mV and a 2.3-fold enhancement of the photocurrent at 1.23 V, versus the reversible hydrogen electrode （RHE）. The borate （Bi） in the Ni-Bi film promotes the release of pro- tons for the oxygen evolution reaction （OER）.展开更多
Developing an efficient artificial photosynthetic system for transforming carbon dioxide and storing solar energy in the form of chemical bonds is one of the greatest challenges in modern chemistry.However,the limited...Developing an efficient artificial photosynthetic system for transforming carbon dioxide and storing solar energy in the form of chemical bonds is one of the greatest challenges in modern chemistry.However,the limited choice of catalysts with wide light absorption range,long-term stability and excellent selectivity for CO_(2) reduction makes the process sluggish.Here,a core-shell-structured nonnoble-metal Ni@In co-catalyst loaded p-type silicon nanowire arrays(SiNWs)for efficient CO_(2) reduction to formate is demonstrated.The formation rate and Faradaic efficiency of formate over the Ni@In/SiNWs catalyst reach 58μmol h^(-1) cm^(-2) and 87% under the irradiation of one simulated sunlight(AM 1.5 G,100 mW cm^(-2)),respectively,which are about 24 and 12 times those over the pristine SiNWs.The enhanced photoelectrocatalytic performance for CO_(2) reduction is attributed to the rational combination of Ni capable of effectively extracting the photogenerated electrons and In responsible for the selective activation of CO_(2).展开更多
A green and efficient method for the selective aerobic oxidation of p-cresol to p-hydroxybenzaldehyde catalyzed by co-catalysts between metalloporphyrins and metal salts was investigated and developed. The relationshi...A green and efficient method for the selective aerobic oxidation of p-cresol to p-hydroxybenzaldehyde catalyzed by co-catalysts between metalloporphyrins and metal salts was investigated and developed. The relationship between the synergistic catalytic effects and the composition as well as amount of co-catalysts was investigated. Moreover, the influence of different reaction conditions was studied in details. A high p-cresol conversion （〉99%） and p-hydroxybenzaldehyde selectivity （83%） were obtained using only 1.125 × 10- 5 mol T（p-CH3O）PPFe111Cl-Co（OAc）2 used under mild, optimized reaction conditions. A possible mechanism for the reaction was also proposed. This work would be meaningful and instructive for the further researches and applications of co-catalyst system on oxidation of cresols and could give some enlightenment on the selectively catalytic oxidation of the side-chain alkyls of aromatics.展开更多
In this paper, a FCC co-catalyst for enhancing the light oil production was prepared by the sol-gel method, and its effect on the performance of residue cracking catalysts was evaluated in a CCFFB reactor. The test re...In this paper, a FCC co-catalyst for enhancing the light oil production was prepared by the sol-gel method, and its effect on the performance of residue cracking catalysts was evaluated in a CCFFB reactor. The test results indicated that the liquid product yield increased obviously, after the surface of FCC equilibrium catalyst was impregnated with the co-catalyst. The yields of dry gas, slurry and coke decreased, while the diesel yield changed slightly. And the crackability of residue was increased; the rate of coke deposition on catalyst surface was decreased, with the thermal cracking reactions inhibited. All these results showed that the co-catalyst could improve the density of acid sites and change the catalyst acidity, which could promote to prolong the catalyst activity by depositing the co-catalyst on the surface of FCC equilibrium catalysts.展开更多
Solar-light-driven CO_(2) reduction CO to CH_(4) and C2H6 is a complex process involving multiple elementary reactions and energy barriers.Therefore,achieving high CH_(4) activity and selectivity remains a significant...Solar-light-driven CO_(2) reduction CO to CH_(4) and C2H6 is a complex process involving multiple elementary reactions and energy barriers.Therefore,achieving high CH_(4) activity and selectivity remains a significant challenge.Here,we integrate bifunctional Cu2O and Cu-MOF(MOF=metal-organic framework)core–shell co-catalysts(Cu2O@Cu-MOF)with semiconductor TiO_(2).Experiments and theoretical calculations demonstrate that Cu2O(Cu+facilitates charge separation)and Cu-MOF(Cu2+improves the CO_(2) adsorption and activation)in the core–shell structure have a synergistic effect on photocatalytic CO_(2) reduction,reducing the formation barrier of the key intermediate*COOH and*CHO.The photocatalyst exhibits high CH_(4) yield(366.0μmol·g^(-1)·h^(-1)),efficient electron transfer(3283μmol·g^(-1)·h^(-1))and hydrocarbon selectivity(95.5%),which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO_(2) reduction reaction.This work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.展开更多
The cobalt-carbonate(CoCi)/NiFeOOH double-layer co-catalyst was prepared on bismuth vanadate(BiVO_(4)).Compared with the same type of electrode(Co-Pi/NiFeOOH/BiVO_(4) and Co-Sil/NiFeOOH/BiVO_(4)),the photoelectrochemi...The cobalt-carbonate(CoCi)/NiFeOOH double-layer co-catalyst was prepared on bismuth vanadate(BiVO_(4)).Compared with the same type of electrode(Co-Pi/NiFeOOH/BiVO_(4) and Co-Sil/NiFeOOH/BiVO_(4)),the photoelectrochemical(PEC)performance of the composite electrode presents the most excellent performance.The Co-Ci/NiFeOOH/BiVO_(4) electrode prepared by photoelectric deposition(PED)achieves a photocurrent density of 4.1 mA/cm^(2) at 1.23 V vs RHE,and the applied bias photon-current efficiency(ABPE)is up to 0.95%.In addition,with the help of the equivalent circuit fitting in electrochemical impedance spectroscopy(EIS),the charge transfer resistance(R_(ct))of Co-Ci/NiFeOOH/BiVO_(4) is only 108.9Ω,which is 16%that of BiVO_(4).The enhanced PEC performance of Co-Ci/NiFeOOH/BiVO_(4) in the double-layer cocatalyst system is attributed to the outstanding advantages of Co-Ci cocatalyst in oxygen vacancy defects,superior to other cobalt-based catalysts in promoting charge transfer and improving the kinetics of water oxidation.This makes Co-Ci co-catalyst become one of the favorable competitors in the field of photoelectric catalysis.展开更多
Carbon nitride(g-C_(3)N_(4))is a promising metal-free and visible-light-responsive photocatalyst.However,its photocatalytic efficiency still suffers from high recombination rates of photoinduced charge carriers,slow k...Carbon nitride(g-C_(3)N_(4))is a promising metal-free and visible-light-responsive photocatalyst.However,its photocatalytic efficiency still suffers from high recombination rates of photoinduced charge carriers,slow kinetics of surface redox reactions,and relatively poor light absorption.Herein,a non-noble metal photocatalyst of MoS_(2) nanodots anchored on P-doped g-C_(3)N_(4) via in situ photodeposition was constructed.With the synergetic effect of the P-doping and MoS_(2) co-catalyst,the as-prepared P-doped g-C_(3)N_(4)/MoS_(2) catalyst has achieved efficient photocatalytic overall water splitting with a hydrogen evolution rate of 121.7μmol h−1 g−1.Experimental results and Density functional theory(DFT)simulations indicate that the enhanced photo-absorption capacity originates from the reduced band gaps by P doping.Meanwhile,the MoS_(2) reduces the overpotential of the water oxidation process and improves hydrogen adsorption capability in the hydrogen evolution reaction.This work can pave a new avenue to design and develop noble-metal-free water-splitting photocatalysts for future large-scale applications.展开更多
In the presentwork,functional diamine groups into indium frameworks to synthesize cyclic carbonates from CO_(2)and epoxides with efficient catalytic activity in the absence of cocatalyst and solvent are reported for t...In the presentwork,functional diamine groups into indium frameworks to synthesize cyclic carbonates from CO_(2)and epoxides with efficient catalytic activity in the absence of cocatalyst and solvent are reported for the first time.Crystalline porous materials(CPM)-5 modified with 1,2-phenylene diamine and ethylene diamine(CPM-5-PhDA and CPM-5-EDA),were prepared using a post-synthetic modification(PSM)method.The properties of the modified CPM-5 were characterized by powder X-ray diffraction(PXRD),Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),N2-adsorption,scanning electron microscopy(SEM),CO_(2)adsorption,and temperature programmed desorption TPD methods.The presence of diamine groups as basic sites and indium Lewis acid sites in the framework structure were desirable for high catalytic activity.For a given catalyst weight,CPM-5-PhDA was the best candidate to appear with great catalytic activity and selectivity for the cycloaddition reaction at 100°C and1MPa CO_(2)under co-catalyst and solvent free conditions.CPM-5-PhDA alsowas found to afford large and bulky epoxides.The catalyst can be easily separated and reused five times without any decline in activity.展开更多
基金supported by National Natural Science Foundation of China(52003240)Zhejiang Provincial Natural Science Foundation of China(LQ21B070007)China Postdoctoral Science Foundation(2022M722818).
文摘Realizing fast and continuous generation of reactive oxygen species(ROSs)via iron-based advanced oxidation processes(AOPs)is significant in the environmental and biological fields.However,current AOPs assisted by co-catalysts still suffer from the poor mass/electron transfer and non-durable promotion effect,giving rise to the sluggish Fe^(2+)/Fe^(3+)cycle and low dynamic concentration of Fe^(2+)for ROS production.Herein,we present a three-dimensional(3D)macroscale co-catalyst functionalized with molybdenum disulfide(MoS_(2))to achieve ultra-efficient Fe^(2+)regeneration(equilibrium Fe^(2+)ratio of 82.4%)and remarkable stability(more than 20 cycles)via a circulating flow-through process.Unlike the conventional batch-type reactor,experiments and computational fluid dynamics simulations demonstrate that the optimal utilization of the 3D active area under the flow-through mode,initiated by the convectionenhanced mass/charge transfer for Fe^(2+)reduction and then strengthened by MoS_(2)-induced flow rotation for sufficient reactant mixing,is crucial for oxidant activation and subsequent ROS generation.Strikingly,the flow-through co-catalytic system with superwetting capabilities can even tackle the intricate oily wastewater stabilized by different surfactants without the loss of pollutant degradation efficiency.Our findings highlight an innovative co-catalyst system design to expand the applicability of AOPs based technology,especially in large-scale complex wastewater treatment.
文摘TiO2 nanosheets mainly exposed （001） facet were prepared through a hydrothermal process with HF as the morphology-directing agent. Ru and RuO2 species were loaded by photo-deposition methods to prepare the photocatalysts. The structural features of the catalysts were characterized by X-ray di raction, transmission electron microscopy, inductively cou-pled plasma atomic emission spectrum, and H2 Temperature-programmed reduction. The photocatalytic property was studied by the O2 evolution from water oxidation, which was examined with respect to the in uences of Ru contents as well as the oxidation and reduction treatments, suggesting the charge separation effect of the Ru species co-catalysts on di erent facets of TiO2 nanosheets. In contrast to Ru/TiO2 and RuO2/TiO2 with the single deposited co-catalyst, the optimized catalyst 0.5%Ru-1.0%RuO2/TiO2 with dual co-catalysts achieved a much improved catalytic performance, in terms of the synergetic effect of dual co-catalysts and the enhanced charge separation effect.
基金supported by the National Natural Science Foundation of China(51672113,51602132)the Six Talent Peaks Project in Jiangsu Province(2015-XCL-026)+2 种基金the Natural Science Foundation of Jiangsu Province(BK20171299)the Training Project of Jiangsu University for Young Cadre Teachers(5521220009)the Youth Research Project of Jiangsu Health and Family Planning Commission in 2016(Q201609)~~
文摘Accelerating the separation efficiency of photoexcited electron-hole pairs with the help of highly active co-catalysts has proven to be a promising approach for improving photocatalytic activity. Thus far, the most developed co-catalysts for semiconductor-based photocatalysis are inorganic materials;the employment of a specific organic molecule as a co-catalyst for photocatalytic hydrogen evolution and pollutant photodegradation is rare and still remains a challenging task. Herein, we report on the use of an organic molecule, oxamide (OA), as a novel co-catalyst to enhance electron- hole separation, photocatalytic H2 evolution, and dye degradation over TiO2 nanosheets. OA-modified TiO2 samples were prepared by a wet chemical route and demonstrated improved light absorption in the visible-light region and more efficient charge transport. The photocatalytic performance of H2 evolution from water splitting and rhodamine B (RhB) degradation for an optimal OA-modified TiO2 photocatalyst reached 2.37 mmol g^–1 h^–1 and 1.43 × 10^-2 min^-1, respectively, which were 2.4 and 3.8 times higher than those of pristine TiO2, respectively. A possible mechanism is proposed, in which the specific π-conjugated structure of OA is suggested to play a key role in the enhancement of the charge transfer and catalytic capability of TiO2. This work may provide advanced insight into the development of a variety of metal-free organic molecules as functional co-catalysts for improved solar-to-fuel conversion and environmental remediation.
基金supported by the National Natural Science Foundation of China(No.11574111 and No.11974129 to X.-F.W.)“the Fundamental Research Funds for the Central Universities.”.
文摘Since their seminal discovery in 2011,two-dimensional(2D)transition metal carbides/nitrides known as MXenes,that constitute a large family of 2D materials,have been targeted toward various applications due to their outstanding electronic properties.MXenes functioning as co-catalyst in combination with certain photocatalysts have been applied in photocatalytic systems to enhance photogenerated charge separation,suppress rapid charge recombination,and convert solar energy into chemical energy or use it in the degradation of organic compounds.The photocatalytic performance greatly depends on the composition and morphology of the photocatalyst,which,in turn,are determined by the method of preparation used.Here,we review the four different synthesis methods(mechanical mixing,self-assembly,in situ decoration,and oxidation)reported for MXenes in view of their application as co-catalyst in photocatalysis.In addition,the working mechanism for MXenes application in photocatalysis is discussed and an outlook for future research is also provided.
基金fundings from the National Natural Science Foundation of China (Nos. 51872173 and 51772167)Taishan Scholarship of Young Scholars (No. tsqn201812068)+2 种基金Natural Science Foundation of Shandong Province (No. ZR2017JL020)Taishan Scholarship of Climbing Plan (No. tspd20161006)Key Research and Development Program of Shandong Province (No. 2018GGX102028)
文摘The biggest challenging issue in photocatalysis is efficient separation of the photoinduced carriers and the aggregation of photoexcited electrons on photocatalyst’s surface.In this paper,we report that double metallic co-catalysts Ti3C2 MXene and metallic octahedral(1T)phase tungsten disulfide(WS2)act pathways transferring photoexcited electrons in assisting the photocatalytic H2 evolution.TiO2 nanosheets were in situ grown on highly conductive Ti3C2 MXenes and 1T-WS2 nanoparticles were then uniformly distributed on TiO2@Ti3C2 composite.Thus,a distinctive 1T-WS2@TiO2@Ti3C2 composite with double metallic co-catalysts was achieved,and the content of 1T phase reaches 73%.The photocatalytic H2 evolution performance of 1T-WS2@TiO2@Ti3C2 composite with an optimized 15 wt%WS2 ratio is nearly 50 times higher than that of TiO2 nanosheets because of conductive Ti3C2 MXene and 1T-WS2 resulting in the increase of electron transfer efficiency.Besides,the 1T-WS2 on the surface of TiO2@Ti3C2 composite enhances the Brunauer–Emmett–Teller surface area and boosts the density of active site.
文摘Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis.However,the biggest challenge in photocatalysis is the efficient separation of photo-induced carriers.To this end,we report that the mesoporous TiO_(2)nanoparticles are anchored on highly conductive Ti_(3)C_(2)MXene co-catalyst by electrostatic self-assembly strategy.The constructed mesoporous TiO_(2)/Ti_(3)C_(2)composites display that the mesoporous TiO_(2)nanoparticles are uniformly distributed on the surface of layer structured Ti_(3)C_(2)nanosheets.More importantly,the as-obtained mesoporous TiO_(2)/Ti_(3)C_(2)composites reveal the significantly enhanced light absorption performance,photo-induced carriers separation and transfer ability,thus boosting the photocatalytic activity.The photocatalytic methyl orange degradation efficiency of mesoporous TiO_(2)/Ti_(3)C_(2)composite with an optimized Ti_(3)C_(2)content(3 wt%)can reach 99.6%within 40 min.The capture experiments of active species confirm that the·O_(2)-and·OH play major role in photocatalytic degradation process.Furthermore,the optimized mesoporous TiO_(2)/Ti_(3)C_(2)composite also shows an excellent photocatalytic H2 production rate of 218.85μmol g^(-1)h^(-1),resulting in a 5.6 times activity as compared with the pristine mesoporous TiO_(2)nanoparticles.This study demonstrates that the MXene family materials can be applied as highly efficient noble-metal-free co-catalysts in the field of photocatalysis.
基金We acknowledge the National Key Research and Development Program of China （2016YFB0600901）, the National Natural Science Foundation of China （21525626, U1463205, U1662111）, the Special- ized Research Fund for the Doctoral Program of Higher Education （20130032120018）, and the Program of Introducing Talents of Disci- pline to Universities （B06006） for financial support.
文摘This paper describes the combinational surface kinetics enhancement and surface states passivation of nickel-borate （Ni-Bi） co-catalyst for a hematite （Fe_2O_3） photoanode. The Ni-Brmodified Fe_2O_3 photoanode exhibits a cathodic onset potential shift of 230 mV and a 2.3-fold enhancement of the photocurrent at 1.23 V, versus the reversible hydrogen electrode （RHE）. The borate （Bi） in the Ni-Bi film promotes the release of pro- tons for the oxygen evolution reaction （OER）.
基金supported by the National Natural Science Foundation of China(Nos.21972115,91945301,21690082 and 21503176)the China Postdoctoral Science Foundation(Nos.2015M570555,2016T90597)。
文摘Developing an efficient artificial photosynthetic system for transforming carbon dioxide and storing solar energy in the form of chemical bonds is one of the greatest challenges in modern chemistry.However,the limited choice of catalysts with wide light absorption range,long-term stability and excellent selectivity for CO_(2) reduction makes the process sluggish.Here,a core-shell-structured nonnoble-metal Ni@In co-catalyst loaded p-type silicon nanowire arrays(SiNWs)for efficient CO_(2) reduction to formate is demonstrated.The formation rate and Faradaic efficiency of formate over the Ni@In/SiNWs catalyst reach 58μmol h^(-1) cm^(-2) and 87% under the irradiation of one simulated sunlight(AM 1.5 G,100 mW cm^(-2)),respectively,which are about 24 and 12 times those over the pristine SiNWs.The enhanced photoelectrocatalytic performance for CO_(2) reduction is attributed to the rational combination of Ni capable of effectively extracting the photogenerated electrons and In responsible for the selective activation of CO_(2).
基金Supported by the National Natural Science Foundation of China(21776259,21776321,21706233,21576297,21476270)
文摘A green and efficient method for the selective aerobic oxidation of p-cresol to p-hydroxybenzaldehyde catalyzed by co-catalysts between metalloporphyrins and metal salts was investigated and developed. The relationship between the synergistic catalytic effects and the composition as well as amount of co-catalysts was investigated. Moreover, the influence of different reaction conditions was studied in details. A high p-cresol conversion （〉99%） and p-hydroxybenzaldehyde selectivity （83%） were obtained using only 1.125 × 10- 5 mol T（p-CH3O）PPFe111Cl-Co（OAc）2 used under mild, optimized reaction conditions. A possible mechanism for the reaction was also proposed. This work would be meaningful and instructive for the further researches and applications of co-catalyst system on oxidation of cresols and could give some enlightenment on the selectively catalytic oxidation of the side-chain alkyls of aromatics.
文摘In this paper, a FCC co-catalyst for enhancing the light oil production was prepared by the sol-gel method, and its effect on the performance of residue cracking catalysts was evaluated in a CCFFB reactor. The test results indicated that the liquid product yield increased obviously, after the surface of FCC equilibrium catalyst was impregnated with the co-catalyst. The yields of dry gas, slurry and coke decreased, while the diesel yield changed slightly. And the crackability of residue was increased; the rate of coke deposition on catalyst surface was decreased, with the thermal cracking reactions inhibited. All these results showed that the co-catalyst could improve the density of acid sites and change the catalyst acidity, which could promote to prolong the catalyst activity by depositing the co-catalyst on the surface of FCC equilibrium catalysts.
基金supported by the National Natural Science Foundation of China(Nos.51802171,52072197,and 52003136)the Outstanding Youth Foundation of Shandong Province,China(No.ZR2019JQ14)+2 种基金the Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(No.2019KJC004)the Major Scientific and Technological Innovation Project(No.2019JZZY020405)Taishan Scholar Program,and the Major Basic Research Program of Natural Science Foundation of Shandong Province(No.ZR2020ZD09).
文摘Solar-light-driven CO_(2) reduction CO to CH_(4) and C2H6 is a complex process involving multiple elementary reactions and energy barriers.Therefore,achieving high CH_(4) activity and selectivity remains a significant challenge.Here,we integrate bifunctional Cu2O and Cu-MOF(MOF=metal-organic framework)core–shell co-catalysts(Cu2O@Cu-MOF)with semiconductor TiO_(2).Experiments and theoretical calculations demonstrate that Cu2O(Cu+facilitates charge separation)and Cu-MOF(Cu2+improves the CO_(2) adsorption and activation)in the core–shell structure have a synergistic effect on photocatalytic CO_(2) reduction,reducing the formation barrier of the key intermediate*COOH and*CHO.The photocatalyst exhibits high CH_(4) yield(366.0μmol·g^(-1)·h^(-1)),efficient electron transfer(3283μmol·g^(-1)·h^(-1))and hydrocarbon selectivity(95.5%),which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO_(2) reduction reaction.This work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.
基金financially supported by the National Natural Science Foundation of China(Nos.52173277 and 21808189)the Key Science and Technology Foundation of Gansu Province,China(No.20YF3GA021)the Natural Science Foundation of Gansu Province,China(No.20JR5RA523).
文摘The cobalt-carbonate(CoCi)/NiFeOOH double-layer co-catalyst was prepared on bismuth vanadate(BiVO_(4)).Compared with the same type of electrode(Co-Pi/NiFeOOH/BiVO_(4) and Co-Sil/NiFeOOH/BiVO_(4)),the photoelectrochemical(PEC)performance of the composite electrode presents the most excellent performance.The Co-Ci/NiFeOOH/BiVO_(4) electrode prepared by photoelectric deposition(PED)achieves a photocurrent density of 4.1 mA/cm^(2) at 1.23 V vs RHE,and the applied bias photon-current efficiency(ABPE)is up to 0.95%.In addition,with the help of the equivalent circuit fitting in electrochemical impedance spectroscopy(EIS),the charge transfer resistance(R_(ct))of Co-Ci/NiFeOOH/BiVO_(4) is only 108.9Ω,which is 16%that of BiVO_(4).The enhanced PEC performance of Co-Ci/NiFeOOH/BiVO_(4) in the double-layer cocatalyst system is attributed to the outstanding advantages of Co-Ci cocatalyst in oxygen vacancy defects,superior to other cobalt-based catalysts in promoting charge transfer and improving the kinetics of water oxidation.This makes Co-Ci co-catalyst become one of the favorable competitors in the field of photoelectric catalysis.
基金supported by Guangdong Basic and Ap-plied Basic Research Foundation(Nos.2021A1515110003 and 2020A1515110332)financial support from the National Natural Science Foundation of China(Nos.51974158 and 21902070)+2 种基金Scientific Research Projects of Key Disciplines in Guangdong Province(No.2019-GDXK-0023)Projects of“Leiyang Scholar”post plan of Lingnan Normal University(2021)Open Project of Key Laboratory of Chean Energy Material Chemistry in Guangdong General University(No.CEMC2022011).
文摘Carbon nitride(g-C_(3)N_(4))is a promising metal-free and visible-light-responsive photocatalyst.However,its photocatalytic efficiency still suffers from high recombination rates of photoinduced charge carriers,slow kinetics of surface redox reactions,and relatively poor light absorption.Herein,a non-noble metal photocatalyst of MoS_(2) nanodots anchored on P-doped g-C_(3)N_(4) via in situ photodeposition was constructed.With the synergetic effect of the P-doping and MoS_(2) co-catalyst,the as-prepared P-doped g-C_(3)N_(4)/MoS_(2) catalyst has achieved efficient photocatalytic overall water splitting with a hydrogen evolution rate of 121.7μmol h−1 g−1.Experimental results and Density functional theory(DFT)simulations indicate that the enhanced photo-absorption capacity originates from the reduced band gaps by P doping.Meanwhile,the MoS_(2) reduces the overpotential of the water oxidation process and improves hydrogen adsorption capability in the hydrogen evolution reaction.This work can pave a new avenue to design and develop noble-metal-free water-splitting photocatalysts for future large-scale applications.
基金Alzahra University Research Council for the financial support
文摘In the presentwork,functional diamine groups into indium frameworks to synthesize cyclic carbonates from CO_(2)and epoxides with efficient catalytic activity in the absence of cocatalyst and solvent are reported for the first time.Crystalline porous materials(CPM)-5 modified with 1,2-phenylene diamine and ethylene diamine(CPM-5-PhDA and CPM-5-EDA),were prepared using a post-synthetic modification(PSM)method.The properties of the modified CPM-5 were characterized by powder X-ray diffraction(PXRD),Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),N2-adsorption,scanning electron microscopy(SEM),CO_(2)adsorption,and temperature programmed desorption TPD methods.The presence of diamine groups as basic sites and indium Lewis acid sites in the framework structure were desirable for high catalytic activity.For a given catalyst weight,CPM-5-PhDA was the best candidate to appear with great catalytic activity and selectivity for the cycloaddition reaction at 100°C and1MPa CO_(2)under co-catalyst and solvent free conditions.CPM-5-PhDA alsowas found to afford large and bulky epoxides.The catalyst can be easily separated and reused five times without any decline in activity.
