The Study On Photocatalytic Activities Of Cu₂S/TiO₂ Composites

Titanium dioxide?TiO₂?has been extensively investigated in many applications owing to its unique properties: abundance in earth,environmental benignancy,safety,and chemical stability.Moreover,TiO₂ exhibit excellent properties in many advanced applications,including photocatalysts,sensors,drug delivery,self-cleanning,and energy storage.However,TiO₂ have wide bandgap?about 3.2ev?which limits its photo-absorption to only the UV region?about 5%of solar light?,and low quantum yield owing to high electron-hole recombination rate.In order to extend their photoresponse to visual part of solar spectrum and thus to improve their photo-catalytic behavior,modification strategies should be taken to narrow down the bandgap.p–n Heterojunction structure is one of the most effective strategies that have been widely applied these year,this paper aim to synthesis p–n Heterojunction by combining narrow bandgap Cu₂ S with wide bandgap TiO₂ semiconductor to improve the photocatalytic activity,Hope that this research could give reference to the photocatalysis-concerned research field.“Dispersion-decomposition” process was adopted to synthesize the Cu₂ S nanocrystals.Experiment shows that the quantity of the copper sulfide to 1-dodecanethiol and reaction temperature had no significant effect on the particle size of the Cu₂ S.Adding 1-octadecene?ODE?can significantly reduce the size of the Cu₂ S.The greater the amount of the ODE,the smaller the particle size of Cu₂ S synthesized.The range of particle size can be controlled from15 nm to 4 nm.At the same time,two kind of TiO₂ with different shapes and crystal type have been synthesized.Spindle-shaped nanoporous anatase TiO₂ mesocrystals with exposed active {101}facets and sheet-shaped anatase TiO₂ with exposed active?001?facets have been successfully prepared through a hydrothermal method with tetrabutyl titanate as the precursor.In addition,commercially brand P25 was taken as control TiO₂ for blank experiment.Based on the above synthesized Cu₂ S and TiO₂,deposition–precipitation process was applied to synthesize the close p-n heterojunction Cu₂S/TiO₂ composites.Highly dispersed Cu₂ S nanoparticles?with different diameter?were loaded on different shaped TiO₂ respectively.This process expects to improve the visible light activity and the stability of Cu₂ S on the catalyst surface.The photodegradation of methylene blue?or rhodamine b?over different Cu₂S/TiO₂ composite was systematically investigated.Experiment shows that the exposed high active facets of TiO₂ together with the loaded Cu₂ S nanoparticles dramatically enhanced the visible light photocatalytic activity of TiO₂.