Preparation, Characterization And Photocatalytic Actives Of Cu-Involved Surface Plasmon Resonance Photocatalyst

Photocatalyst can be used for splitting water for hydrogen evolution,reduction carbon dioxide,and degradation pollutants under sunlight irradiation,providing a brand new solution for energy crisis and environmental issues.On the one hand,semiconductor-based photocatalyst has been extensively and deeply investigated.However,the narrow light response range,low utilization rate of solar light and serious recombination of photo-induced electron-hole pairs result in poor photocatalytic efficiency.Anatase TiO₂ and g-C₃N₄ have become a hot spot in the field of photocatalysis due to their high stability and photocatalytic ability.On the other hand,surface plasmonic photocatalyst with surface plasmonic resonant effect gradually emerges and attracts great interest due to broad spectrum absorption and efficient separation of photo-induced charge.Surface plasmonic resonant effect mainly exist in noble metal?such as Au,Ag and Pt?,which acts as co-catalyst in photocatalytic system.However,noble metal has rarely been reported as photocatalyst alone,and non-noble metal has been even less reported.In this dissertation,we mainly focus on the photocatalytic hydrogen evolution activity of semiconductor-based and plasmonic Cu-based photocatalyst,and photocatalytic abilities are improved by increase of separation efficiency of photo-induced charge with various methods.The details are as follows:1.Anatase TiO₂ was prepared by a hydrothermal method and modified with Cu nanoparticles,then sensitized with Erythrosin B.The highest H₂ evolution rate was 13.4mmol g^-1 h^-1,which is 37 times higher than that of pure TiO₂.Photocatalytic H₂ evolution activity doesn't show significant decrease in six consecutive runs of accumulatively 24 h.2.Porous graphitic carbon nitride?g-C₃N₄?was synthesized by thermo polymerization method.Cu-Cu₂O or Cu nanoparticles were loaded on the surface of g-C₃N₄ and then sensitized with Erythrosin B.Compared with pure g-C₃N₄,great improvement of photocatalytic H₂ evolution rates was obtained for modified composites.3.Plasmonic Cu nanoparticles photocatalysts were prepared by photo-reduction method with lactic acid as reductant.After combined with carbon materials?reduced graphene oxide and carbon quantum dots?,significant enhancement of photocatalytic activity was achieved for composites.The highest H₂ evolution rate was 64 mmol g^-1 h^-1,which is twice higher than that of pure Cu nanoparticles.More importantly,these plasmonic photocatalysts exhibit broad spectrum response,even in the near-infrared region.4.Dendrite-like plasmonic CuNi bimetal photocatalyst was synthesized by hydrothermal method,which also exhibits near-infrared photocatalytic response.By varying the fraction of bimetal and carbon materials in this system,the most reactive photocatalyst was obtained.Furthermore,photocatalytic hydrogen evolution activity was detected in the absence of sacrificial agent for bimetal/carbon material composites,realizing overall water splitting.5.Dendrite-like plasmonic CuCo bimetal photocatalyst was synthesized by hydrothermal method.Overall water splitting was realized under sunlight irradiation.Photocatalytic hydrogen evolution rate was relative low at beginning in the photocatalytic process,and then it increases and stabilizes due to H₂ absorbtion on the surface of Co nanosheets.The integration of hydrogen evolution and storage was realized in this device.