Preparation Of A Photocatalyst Of New Sulfide For Selective Photosynthesis Of Organic Aromatic Compounds Under Visible Light

Ternary chalcogenide photocatalyst,cadmium indium sulfide(Cd In2S4),was prepared by a simple solvothermal method using ethylene glycol as solvent,as well as indium chloride tetrahydrate(InCl3.4H2O),cadmium nitrate tetrahydrate [Cd(NO3)2.4H2O],and thiacetamide(TAA)as precursors.The structure and optical properties of resulting sample was characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray powder diffraction(XRD),UV-vis diffuse reflection spectroscopy(DRS),Brunauer-Emmett-Teller(BET)specific surface area,X-ray photoelectron spectroscopy(XPS)and electrochemical test.The photocatalytic activities of the CdIn2S4 synthesized at different time were initially studied by selective oxidation of aromatic alcohol to aromatic aldehyde and reduction of nitrobenzene into aniline under the irradiation of visible light in N2 purge condition.Then through the Conversion,Yield and Selectivity to verify the photocatalytic activity.With the in-depth research,we also learened the reaction disciplinarian of one-pot route to synthesize imine compounds from aromatic alcohols and nitrobenzenes in a coupled system.The results showed that Cd In2S4 photocatalysts synthesized at different times almost have similar photocatalytic activity.When the reaction time is 6 h,the conversions of benzyl alcohol and nitrobenzene are 74% and 57%,respectively.The corresponding yields of benzaldehyde and aniline are 65% and 11%,respectively.In the study of one-pot route to synthesize C=N compounds,under illumination for 4 h,the yield of Schiff based products is about 32%,the production of water in reaction is an important influence factor,it can determine the direction of Schiff base reaction.Through the experiments of scavengers(triethanolamine and carbon tetrachloride),we confirmed that holes(h+)and electrons(e-)are playing decisive role in the coupled systemin.The H+ protons which produced by oxidation and electrons are indispensable for reduction of nitrobenzene.In short,the oxidation reaction can occur alone,but thereduction reaction is synergetic.Through the isotope experiments,we have learned that the two H protons removed from aromatic alcohols to aromatic aldehyedes under N2 atmosphere,one comes from –CH2–,the other comes from –OH.Through a series of control experiments between In2S3,CdS and CdIn2S4(preparation in the same condition),the results exhibit that CdIn2S4 photocatalyst has an outstanding photocatalytic activity for selective oxidation of benzyl alcohols to benzaldehydes.Therefore,the CdIn2S4 catalyst synthesized by solvothermal method has considerable catalytic activity and high stability,it has a good prospect in photosynthesis of organic aromatic compounds.