Study On Properties Of Organics Formation And Hydrogen Production With Sulfide Semiconductor Photocatalyst

Selective oxidation of aromatic alcohols to corresponding carbonyl compounds using mild condition has a promising prospect in industry.In the paper,we combine photocatalysis with thermocatalysis for the first time to fabricate a new mode of photothermocatalyst,Zn₃In₂S₆@Zn O composite,with hierarchical structure by a hydrothermal method and a solvent assisted interfacial reaction.The catalysts were characterized by X-ray powder diffraction?XRD?,X-ray photoelectron spectroscopy?XPS?,scanning electron microscopy?SEM?,transmission electron microscopy?TEM?and TEM mapping,UV-vis diffuse reflection spectroscopy?DRS?and Brunauer-Emmett-Teller?BET?surface area.Under visible light illumination,Zn₃In₂S₆@10%Zn O exhibits dramatic enhancement of reaction activity for selective oxidation of benzyl alcohol to benzaldehyde compared with single Zn₃In₂S₆ and Zn O.The enhanced activity of Zn₃In₂S₆@Zn O is mainly attributed to the synergistic effect of photocatalysis on Zn₃In₂S₆ and low-temperature thermocatalysis on Zn O.The stable performance and broad-spectrum activity of Zn₃In₂S₆@Zn O for other aromatic alcohols indicate its applicable potential.The synergistic effect between the photocatalysis and the thermocatalysis was investigated by the photoelectrochemical andphotoluminescence?PL?experiments and a series of control experiments.On the basis of the results of experiments,a probable mechanism of synergetic effect was proposed.This study provides a promising way to combine photocatalysis and thermocatalysis for the design of novel and efficient visible-light-driven catalyst for selective oxidation of aromatic alcohols or other organics under mild reaction conditions.Meanwhile,selective oxidation aromatic alcohols to corresponding carbonyl compounds without oxygen is a new type of reaction.We found that not only carbonyl compounds be produced but also the hydrogen.A more meaningful value of this reaction is that not only the most promising energy?H₂?and fine chemicals?aromaticaldehydes?can be produced,but also the photoexcited electron-hole pairs can be used fully to avoid energy loss.The Zn₃In₂S₆ is thought as main part of catalystand loaded with Pt to form Pt/Zn₃In₂S₆ by photo-reduction of chloroplatinic acid.The catalytic activity of Pt/Zn₃In₂S₆ is much higher than pure Zn₃In₂S₆ in reaction of selective oxition of aromatic alcohols to corresponding carbonyl compounds and H₂.The photocatalysts of Zn₃In₂S₆ and Pt/Zn₃In₂S₆ are phenotypic analyzed by XRD?XPS?SEM ? TEM ? DRS and electrochemical workstation.At the end,the reaction mechanismwas deeper studied through fluorescence method,control experiments,elemental tracing method and so on.And a possible mechanism was proposed.