Photocatalytic Hproduction from water splitting has a promising prospect for alleviating energy and environmental issues.However,the fast recombination of photogenerated charge carriers limits the photocatalytic effic...Photocatalytic Hproduction from water splitting has a promising prospect for alleviating energy and environmental issues.However,the fast recombination of photogenerated charge carriers limits the photocatalytic efficiency and its practical application.Cocatalyst engineering is an effective strategy to spatially separate photogenerated charge carriers.In this work,noble-metal-free MoSand CoOcocatalysts are loaded on CdS nanorods by a two-step photodeposition method.The MoSfunctions as the reduction cocatalyst to trap electrons and Co Oas the oxidation cocatalyst to trap holes.Transmission electron microscopy(TEM),inductively coupled plasma(ICP),X-ray photoelectron spectroscopy(XPS)and MottSchottky results demonstrate the effectiveness of photodeposition for loading MoSand CoOdual cocatalysts on CdS and their impact on the photochemical properties.The optimized CdS-MoS-CoOcomposite exhibits a high photocatalytic H-production rate of 7.4 mmol g^(-1)h^(-1)and an apparent quantum efficiency(QE)of 7.6%at 420 nm.Further analysis on time-resolved photoluminescence(TRPL)indicates that the introduction of dual cocatalysts greatly prolongs the lifetime of photogenerated charge carriers and deceases the charge recombination rates,consequently leading to superior photocatalytic H-production performance.This work provides a facile and effective strategy for the construction of highly efficient dual-cocatalyst-modified CdS photocatalyst for high-performance photocatalytic Hproduction.展开更多
Cobalt-based oxides,with high abundance,good stability and excellent catalytic performance,are regarded as promising photocatalysts for artificial photosynthetic systems to alleviate foreseeable energy shortages and g...Cobalt-based oxides,with high abundance,good stability and excellent catalytic performance,are regarded as promising photocatalysts for artificial photosynthetic systems to alleviate foreseeable energy shortages and global warming.Herein,for the first time,a series of novel spongy porous CDs@CoOx materials were synthesized to act as an efficient and stable bifunctional photocatalyst for water oxidation and CO2 reduction.Notably,the preparation temperatures visibly influence the morphologies and photocatalytic performances of the CDs@CoOx.Under the optimal conditions,a maximum O2 yield of 40.4% and pretty apparent quantum efficiency(AQE)of 58.6% at 460 nm were obtained over CDs@CoOx-300 for water oxidation.Similarly,the optimized sample CDs@CoOx-300 manifests significant enhancement on the CO2-to-CO conversion with a high selectivity of 89.3% and CO generation rate of 8.1μmol/h,which is superior to most previous cobalt-based catalysts for CO2 reduction.The composite CDs@CoOx-300 not only exposes more active sites but also facilitates electron transport,which results in excellent photocatalytic activity.In addition,the boosted photocatalytic behavior is attributed to the synergistic effect between CoOx and CDs,which was verified by the photocatalytic activity control experiments and electrochemical characterization.The work offers a novel strategy to fabricate a high performance bifunctional photocatalyst for water oxidation and CO2 reduction.展开更多
A series of cobalt doped TiO2（Co-TiO2） and Co Oxloaded TiO2（Co/TiO2） catalysts prepared by sol–gel and impregnation methods respectively were investigated on selective catalytic reduction with NH3（NH3-SCR） of N...A series of cobalt doped TiO2（Co-TiO2） and Co Oxloaded TiO2（Co/TiO2） catalysts prepared by sol–gel and impregnation methods respectively were investigated on selective catalytic reduction with NH3（NH3-SCR） of NO. It was found that Co-TiO2 catalyst showed more preferable catalytic activity at low temperature range. From characterization results of XRD,TEM, Raman and FT-IR, Co species were proved to be doped into TiO2 lattice by replaced Ti atoms. After being characterized and analyzed by NH3-TPD, PL, XPS, EPR and DRIFTS, it was found that the better NH3-SCR activities of Co-TiO2 catalysts, compared with Co/TiO2 catalyst, were ascribed to the formation of more oxygen vacancies which further promoted the production of more superoxide ions（O-2）. The superoxide ions were crucial for the formation of low temperature SCR reaction intermediates（NO-3） by reacting with adsorbed NO molecule. Therefore, these aspects were responsible for the higher low temperature NH3-SCR activity of Co-TiO2 catalysts.展开更多
Artificial Z-scheme photocatalytic systems have received considerable attention in recent years because they can achieve wide light-absorption, high charge-separation efficiency, and strong redox ability simultaneousl...Artificial Z-scheme photocatalytic systems have received considerable attention in recent years because they can achieve wide light-absorption, high charge-separation efficiency, and strong redox ability simultaneously. Nevertheless, it is still challenging to exploit low-cost and stable Zscheme photocatalysts with highly-efficient H2 evolution from solar water-splitting so far. Herein, we report a novel all-solidstate Z-scheme photocatalyst Cd1-xZnxS@WO3-x consisting of Cd1-xZnxS nanorods coated with oxygen-deficient WO3-x amorphous layers. The Cd1-xZnxS@WO3-x exhibits an outstanding H2 evolution reaction(HER) activity as compared with Pt-loaded Cd1-xZnxS and most WO3- and Cd S-based photocatalysts, due to the generation of stronger reducing electrons through the appropriate Zn-doping in Cd1-xZnxS and the enhanced charge transfer by introducing oxygen vacancies(W^5+/OVs) into the ultrathin WO3-x amorphous coatings. The optimal HER rate of Cd1-xZnxS@WO3- xis determined to be 21.68 mmol h^-1 g^-1, which is further raised up to 28.25 mmol h^-1 g^-1(about 12 times more than that of Pt/Cd1-xZnxS) when Cd1-xZnxS@WO3-x is hybridized by Co Ox and Ni Oxdual cocatalysts(Cd1-xZnxS@WO3-x/CoOx/NiOx)through in-situ photo-deposition. Moreover, the corresponding apparent quantum yield(AQY) at 420 nm is significantly increased from 34.6% for Cd1-xZnxS@WO3-x to 60.8% for Cd1-xZnxS@WO3-x/CoOx/NiOx. In addition, both Cd1-xZnxS@WO3-x and Cd1-xZnxS@WO3-x/CoOx/NiOx demonstrate good stability towards HER. The results displayed in this work will inspire the rational design and synthesis of high-performance nanostructures for photocatalytic applications.展开更多
While heterojunction engineering holds promise for enhancing NiFe-based oxygen evolution reaction(OER)catalysts,poorly matched interfacial Fermi levels often hinder the formation of high-valent Ni2+δspecies critical ...While heterojunction engineering holds promise for enhancing NiFe-based oxygen evolution reaction(OER)catalysts,poorly matched interfacial Fermi levels often hinder the formation of high-valent Ni2+δspecies critical for OER activity,creating a trade-off between charge-transfer efficiency and active-phase evolution.Herein,a band alignment strategy is proposed to resolve this conflict by controlled integration of Co nanodots(20 wt%)into electrospun carbon nanofibers(CoO_(x)-CNF),followed by robust coupling of NiFe LDH nanosheets.The presence of Co nanodots enhances CNF graphitization and tailors the interfacial Fermi level offset to 1.30 eV,thereby establishing directional electron transfer channels from NiFe LDH to CoO_(x)-CNF.The resulting space charge remodeling induces selective electron depletion at Ni sites,which synergistically promotes the formation of catalytically active Ni2+δspecies while accelerating charge transfer.Therefore,such an elaborately designed NiFe LDH@CoO_(x)-CNF catalyst achieves an ultralow overpotential of 225 mV at 10 mA cm^(-2) and exceptional stability for 100 h at 100 mA cm^(-2).Operando electrochemical impedance spectroscopy directly tracks microscopic interfacial reactions and charge-transfer mechanisms,while DFT calculations reveal that the band alignment-mediated space charge effect improves the electronic structure and strengthens Ni 3d–O 2p hybridization,thus lowering the Gibbs free energy barrier of the ratedetermining step(*O→*OOH).This work establishes a“band alignment→space charge remodeling→kinetic enhancement”paradigm for phase-selective electrocatalyst design.展开更多
基金the National Science Foundation of China(Nos.22005228 and 52063028)。
文摘Photocatalytic Hproduction from water splitting has a promising prospect for alleviating energy and environmental issues.However,the fast recombination of photogenerated charge carriers limits the photocatalytic efficiency and its practical application.Cocatalyst engineering is an effective strategy to spatially separate photogenerated charge carriers.In this work,noble-metal-free MoSand CoOcocatalysts are loaded on CdS nanorods by a two-step photodeposition method.The MoSfunctions as the reduction cocatalyst to trap electrons and Co Oas the oxidation cocatalyst to trap holes.Transmission electron microscopy(TEM),inductively coupled plasma(ICP),X-ray photoelectron spectroscopy(XPS)and MottSchottky results demonstrate the effectiveness of photodeposition for loading MoSand CoOdual cocatalysts on CdS and their impact on the photochemical properties.The optimized CdS-MoS-CoOcomposite exhibits a high photocatalytic H-production rate of 7.4 mmol g^(-1)h^(-1)and an apparent quantum efficiency(QE)of 7.6%at 420 nm.Further analysis on time-resolved photoluminescence(TRPL)indicates that the introduction of dual cocatalysts greatly prolongs the lifetime of photogenerated charge carriers and deceases the charge recombination rates,consequently leading to superior photocatalytic H-production performance.This work provides a facile and effective strategy for the construction of highly efficient dual-cocatalyst-modified CdS photocatalyst for high-performance photocatalytic Hproduction.
文摘Cobalt-based oxides,with high abundance,good stability and excellent catalytic performance,are regarded as promising photocatalysts for artificial photosynthetic systems to alleviate foreseeable energy shortages and global warming.Herein,for the first time,a series of novel spongy porous CDs@CoOx materials were synthesized to act as an efficient and stable bifunctional photocatalyst for water oxidation and CO2 reduction.Notably,the preparation temperatures visibly influence the morphologies and photocatalytic performances of the CDs@CoOx.Under the optimal conditions,a maximum O2 yield of 40.4% and pretty apparent quantum efficiency(AQE)of 58.6% at 460 nm were obtained over CDs@CoOx-300 for water oxidation.Similarly,the optimized sample CDs@CoOx-300 manifests significant enhancement on the CO2-to-CO conversion with a high selectivity of 89.3% and CO generation rate of 8.1μmol/h,which is superior to most previous cobalt-based catalysts for CO2 reduction.The composite CDs@CoOx-300 not only exposes more active sites but also facilitates electron transport,which results in excellent photocatalytic activity.In addition,the boosted photocatalytic behavior is attributed to the synergistic effect between CoOx and CDs,which was verified by the photocatalytic activity control experiments and electrochemical characterization.The work offers a novel strategy to fabricate a high performance bifunctional photocatalyst for water oxidation and CO2 reduction.
基金financially supported by the Key Project of Chinese National Programs for Research and Development(No.2016YFC0203800)the National Natural Science Foundation of China(Nos.51408309 and 51578288)+4 种基金the Science and Technology Support Program of Jiangsu Province(No.E2014713)the Natural Science Foundation of Jiangsu Province(No.BK20140777)the Industry-Academia Cooperation Innovation Fund Projects of Jiangsu Province(No.BY2014004-10)the Jiangsu Province Scientific and Technological Achievements into a Special Fund Project(No.BA2015062)the Top-notch Academic Programs of Jiangsu Higher Education Institutions
文摘A series of cobalt doped TiO2（Co-TiO2） and Co Oxloaded TiO2（Co/TiO2） catalysts prepared by sol–gel and impregnation methods respectively were investigated on selective catalytic reduction with NH3（NH3-SCR） of NO. It was found that Co-TiO2 catalyst showed more preferable catalytic activity at low temperature range. From characterization results of XRD,TEM, Raman and FT-IR, Co species were proved to be doped into TiO2 lattice by replaced Ti atoms. After being characterized and analyzed by NH3-TPD, PL, XPS, EPR and DRIFTS, it was found that the better NH3-SCR activities of Co-TiO2 catalysts, compared with Co/TiO2 catalyst, were ascribed to the formation of more oxygen vacancies which further promoted the production of more superoxide ions（O-2）. The superoxide ions were crucial for the formation of low temperature SCR reaction intermediates（NO-3） by reacting with adsorbed NO molecule. Therefore, these aspects were responsible for the higher low temperature NH3-SCR activity of Co-TiO2 catalysts.
基金financially supported by the National Natural Science Foundation of China (51572136, 51772162, 21571112, 51802170 and 21801150)the Natural Science Foundation of Shandong Province (ZR2018BEM014, ZR2018LB008 andZR2019MB001)+2 种基金Taishan Scholar Foundation of Shandong Province (H. W., ts201712047)the Special Fund Project to Guide Development of Local Science and Technology by Central Government (H.W.)Taishan Scholar Program of Advantage and Characteristic Discipline Team of Eco Chemical Process and Technology
文摘Artificial Z-scheme photocatalytic systems have received considerable attention in recent years because they can achieve wide light-absorption, high charge-separation efficiency, and strong redox ability simultaneously. Nevertheless, it is still challenging to exploit low-cost and stable Zscheme photocatalysts with highly-efficient H2 evolution from solar water-splitting so far. Herein, we report a novel all-solidstate Z-scheme photocatalyst Cd1-xZnxS@WO3-x consisting of Cd1-xZnxS nanorods coated with oxygen-deficient WO3-x amorphous layers. The Cd1-xZnxS@WO3-x exhibits an outstanding H2 evolution reaction(HER) activity as compared with Pt-loaded Cd1-xZnxS and most WO3- and Cd S-based photocatalysts, due to the generation of stronger reducing electrons through the appropriate Zn-doping in Cd1-xZnxS and the enhanced charge transfer by introducing oxygen vacancies(W^5+/OVs) into the ultrathin WO3-x amorphous coatings. The optimal HER rate of Cd1-xZnxS@WO3- xis determined to be 21.68 mmol h^-1 g^-1, which is further raised up to 28.25 mmol h^-1 g^-1(about 12 times more than that of Pt/Cd1-xZnxS) when Cd1-xZnxS@WO3-x is hybridized by Co Ox and Ni Oxdual cocatalysts(Cd1-xZnxS@WO3-x/CoOx/NiOx)through in-situ photo-deposition. Moreover, the corresponding apparent quantum yield(AQY) at 420 nm is significantly increased from 34.6% for Cd1-xZnxS@WO3-x to 60.8% for Cd1-xZnxS@WO3-x/CoOx/NiOx. In addition, both Cd1-xZnxS@WO3-x and Cd1-xZnxS@WO3-x/CoOx/NiOx demonstrate good stability towards HER. The results displayed in this work will inspire the rational design and synthesis of high-performance nanostructures for photocatalytic applications.
基金funded by the Soft Science Project of the Shanghai Science and Technology Commission(No.24692115200)the National Natural Science Foundation of China(No.12304467)+1 种基金the China Postdoctoral Science Foundation(No.2023M732175),and the Project of Digital Medical Research Institute of Shanghai University(No.SHU-UM-JBGS-2025-11)In addition,we also appreciate the High Performance Computing Center of Shanghai University and the Shanghai Engineering Research Center of Intelligent Computing System(No.19DZ2252600)for supplying computational facilities and technical assistance.
文摘While heterojunction engineering holds promise for enhancing NiFe-based oxygen evolution reaction(OER)catalysts,poorly matched interfacial Fermi levels often hinder the formation of high-valent Ni2+δspecies critical for OER activity,creating a trade-off between charge-transfer efficiency and active-phase evolution.Herein,a band alignment strategy is proposed to resolve this conflict by controlled integration of Co nanodots(20 wt%)into electrospun carbon nanofibers(CoO_(x)-CNF),followed by robust coupling of NiFe LDH nanosheets.The presence of Co nanodots enhances CNF graphitization and tailors the interfacial Fermi level offset to 1.30 eV,thereby establishing directional electron transfer channels from NiFe LDH to CoO_(x)-CNF.The resulting space charge remodeling induces selective electron depletion at Ni sites,which synergistically promotes the formation of catalytically active Ni2+δspecies while accelerating charge transfer.Therefore,such an elaborately designed NiFe LDH@CoO_(x)-CNF catalyst achieves an ultralow overpotential of 225 mV at 10 mA cm^(-2) and exceptional stability for 100 h at 100 mA cm^(-2).Operando electrochemical impedance spectroscopy directly tracks microscopic interfacial reactions and charge-transfer mechanisms,while DFT calculations reveal that the band alignment-mediated space charge effect improves the electronic structure and strengthens Ni 3d–O 2p hybridization,thus lowering the Gibbs free energy barrier of the ratedetermining step(*O→*OOH).This work establishes a“band alignment→space charge remodeling→kinetic enhancement”paradigm for phase-selective electrocatalyst design.
