Simultaneous generation of H_(2) fuel and value-added chemicals has attracted increasing attention since the photogenerated electrons and holes can be both employed to convert solar light into chemical energy.Herein,f...Simultaneous generation of H_(2) fuel and value-added chemicals has attracted increasing attention since the photogenerated electrons and holes can be both employed to convert solar light into chemical energy.Herein,for realizing UV-visible-NIR light driven dehydrogenation of benzyl alcohol(BA)into benzaldehydes(BAD)and H_(2),a novel localized surface plasmon resonance(LSPR)enhanced S-scheme heterojunction was designed by combining noble-metal-free plasmon MoO_(3-x) as oxidation semiconductor and Zn_(0.1)Cd_(0.9)S as reduction semiconductor.The photoredox system of Zn_(0.1)Cd_(0.9)S/MoO_(3-x) displayed an unconventional reaction model,in which the BA served as both electron donor and acceptor.The S-scheme charge transfer mechanism induced by the formed internal electric field enhanced the redox ability of charge carriers thermodynamically and boosted charge separation kinetically.Moreover,due to the LSPR effect of MoO_(3-x) nanosheets,Zn_(0.1)Cd_(0.9)S/MoO_(3-x) photocatalysts exhibited strong absorption in the region of full solar spectrum.Therefore,the Zn_(0.1)Cd_(0.9)S/MoO_(3-x) composite generated H_(2) and BAD simultaneously via selective oxidation of BA with high production(34.38 and 33.83 mmol×g^(–1) for H_(2) and BAD,respectively)upon full solar illumination.Even under NIR light irradiation,the H_(2) production rate could up to 94.5 mmol×g^(–1)×h^(–1).In addition,the Zn_(0.1)Cd_(0.9)S/MoO_(3-x) composite displayed effective photocatalytic H_(2) evolution rate up to 149.2 mmol×g^(–1)×h^(–1) from water,which was approximate 6 times that of pure Zn_(0.1)Cd_(0.9)S.This work provides a reference for rational design of plasmonic S-scheme heterojunction photocatalysts for coproduction of high-value chemicals and solar fuel production.展开更多
V-doped TiO2 nanoparticles（NPs） as dye adsorbents are synthesized by the co-precipitation method and characterized by X-ray powder diffraction, transmission electron microscope, N2 adsorption at 77 K, and X-ray phot...V-doped TiO2 nanoparticles（NPs） as dye adsorbents are synthesized by the co-precipitation method and characterized by X-ray powder diffraction, transmission electron microscope, N2 adsorption at 77 K, and X-ray photoelectron spectroscopy. The adsorption of methylene blue（MB） on the V-doped TiO2 NPs is studied in detail by varying the calcination temperature and V doping amount of the adsorbent, adsorbate concentration, adsorbent dosage, agitation rate, reaction temperature, and p H. The comparison of dye adsorption on V-doped TiO2 and parent TiO2 demonstrates that the adsorptive activity of TiO2 can be improved by V doping. The enhanced adsorptive performance can be attributed to the tremendous changes in texture, structure, and surface morphology of adsorbent. The adsorption kinetic analysis shows that the adsorption follows the pseudo-second order kinetics. The apparent activation energy for adsorption is calculated by Arrhenius formula to be 37.6 k J·mol-1, indicating that the adsorption is controlled by both of the diffusion and interfacial adsorption steps. The adsorption data are analyzed using Langmuir and Freundlich isotherms and the results indicate that the Langmuir model provides better correlation of the experimental data. The results conclusively show that the adsorption of MB is a spontaneous behavior and endothermic reaction with the ΔH value of 17.60 k J·mol-1.展开更多
文摘Simultaneous generation of H_(2) fuel and value-added chemicals has attracted increasing attention since the photogenerated electrons and holes can be both employed to convert solar light into chemical energy.Herein,for realizing UV-visible-NIR light driven dehydrogenation of benzyl alcohol(BA)into benzaldehydes(BAD)and H_(2),a novel localized surface plasmon resonance(LSPR)enhanced S-scheme heterojunction was designed by combining noble-metal-free plasmon MoO_(3-x) as oxidation semiconductor and Zn_(0.1)Cd_(0.9)S as reduction semiconductor.The photoredox system of Zn_(0.1)Cd_(0.9)S/MoO_(3-x) displayed an unconventional reaction model,in which the BA served as both electron donor and acceptor.The S-scheme charge transfer mechanism induced by the formed internal electric field enhanced the redox ability of charge carriers thermodynamically and boosted charge separation kinetically.Moreover,due to the LSPR effect of MoO_(3-x) nanosheets,Zn_(0.1)Cd_(0.9)S/MoO_(3-x) photocatalysts exhibited strong absorption in the region of full solar spectrum.Therefore,the Zn_(0.1)Cd_(0.9)S/MoO_(3-x) composite generated H_(2) and BAD simultaneously via selective oxidation of BA with high production(34.38 and 33.83 mmol×g^(–1) for H_(2) and BAD,respectively)upon full solar illumination.Even under NIR light irradiation,the H_(2) production rate could up to 94.5 mmol×g^(–1)×h^(–1).In addition,the Zn_(0.1)Cd_(0.9)S/MoO_(3-x) composite displayed effective photocatalytic H_(2) evolution rate up to 149.2 mmol×g^(–1)×h^(–1) from water,which was approximate 6 times that of pure Zn_(0.1)Cd_(0.9)S.This work provides a reference for rational design of plasmonic S-scheme heterojunction photocatalysts for coproduction of high-value chemicals and solar fuel production.
基金financially supported by the NNSFC(Nos.21003021,21173044,21473096)the Science and Technology Project of the Education Office of Fujian Province(JA12017)+3 种基金National Basic Research Program of China(973 Program,No.2012CB722607)the Science and Technology Project of Fujian Province(Nos.2007J0359,2006F5030,CE0015)the Ningde Normal University projects on serving the western coast to the TW strait(No.2010H103)the Project of Fujian Province Communications Department(No.201323)
文摘V-doped TiO2 nanoparticles（NPs） as dye adsorbents are synthesized by the co-precipitation method and characterized by X-ray powder diffraction, transmission electron microscope, N2 adsorption at 77 K, and X-ray photoelectron spectroscopy. The adsorption of methylene blue（MB） on the V-doped TiO2 NPs is studied in detail by varying the calcination temperature and V doping amount of the adsorbent, adsorbate concentration, adsorbent dosage, agitation rate, reaction temperature, and p H. The comparison of dye adsorption on V-doped TiO2 and parent TiO2 demonstrates that the adsorptive activity of TiO2 can be improved by V doping. The enhanced adsorptive performance can be attributed to the tremendous changes in texture, structure, and surface morphology of adsorbent. The adsorption kinetic analysis shows that the adsorption follows the pseudo-second order kinetics. The apparent activation energy for adsorption is calculated by Arrhenius formula to be 37.6 k J·mol-1, indicating that the adsorption is controlled by both of the diffusion and interfacial adsorption steps. The adsorption data are analyzed using Langmuir and Freundlich isotherms and the results indicate that the Langmuir model provides better correlation of the experimental data. The results conclusively show that the adsorption of MB is a spontaneous behavior and endothermic reaction with the ΔH value of 17.60 k J·mol-1.
