Photocatalytic Activity Improvement Of Copper Phenylacetylene By Adjusting Its Valence Band

As a typical metal-organic coordination compound,PhC₂Cu（Copper phenylacetylene）has shown great potential in the field of photocatalysis due to its good light absorption ability and fairly negative conduction band potential（-2.32V vs.SHE）.However,the limited valence band potential is the biggest disadvantage for the high photocatalytic performance of PhC₂Cu.Therefore,this research mainly focused on enhancing the photocatalytic performance of PhC₂Cu by adjusting its valence band.The catalyst activities of the prepared samples were characterized by the photocatalytic degradation of methyl orange（MO）and 2,4-dichlorophenol（2,4-DCP）.In addition,the mechanisms of the photocatalytic activity improvement were also detailedly studied in this research.The main contents are as follows:Firstly,a trace amount of iron（the mole ratio of Fe to Cu is 0%-3%）is doped in the preparation of PhC₂Cu.The result shows that,the photocatalytic degradations of MO and 2,4-DCP over 2%Fe-PhC₂Cu are increased by 2 times and 1.6 times,respectively,than those over pure PhC₂Cu.The key factors for improving the performance of Fe-PhC₂Cu are the narrower band gap,the positive shift of valence band,as well as the enhanced hole-electron pairs separation and transfer.Secondly,a targeted Z-Scheme heterojunction was constructed by grafting PhC₂Cu molecular on the surface ofα-Bi₂O₃,which promotes the separation of photogenerated carriers of copper phenylacetylene,and rational utilization of photogenerated holes with strong oxidation capacity inα-Bi₂O₃.In addition,due to the high dispersion of PhC₂Cu on the surface ofα-Bi₂O₃,the composite material can handle high concentration of MO aqueous solution in a short time.Among them,the degradation rate of MO by 10%α-Bi₂O₃/PhC₂Cu was 28 times and 13 times higher than that of pureα-Bi₂O₃ and PhC₂Cu,respectively.In this works,the photocurrent density,photoluminescence spectrum（PL）,generation of reactive oxygen species and deposition of silver were performed to demonstrate the formation of Z-scheme heterojunction.In these works,the corresponding samples were prepared and characterized by XRD,FT-IR,UV-vis DRS,XPS,SEM,TEM,etc.In the previous work,our research proved that doping with a small amount of cheap metal iron will promote the improvement of the photocatalytic activity of the material by inducing the continuous positive shift of the PhC₂Cu energy band structure.In the latter work,we found that simply mixingα-Bi₂O₃ during the preparation of PhC₂Cu can not only improve the hydrophilicity of PhC₂Cu,but also constructing Z-scheme between PhC₂Cu andα-Bi₂O₃,which makes the photo-generated carrier’s characteristics and transfer paths within the material change in a favorable direction.Overall,these two researches provide meaningful strategies for improving the photocatalytic activity of PhC₂Cu.