| Semiconductor photocatalysts can be used at room temperature,and take light irradiation as the main driving force to catalytic decomposition of organic matter.Because of its green features,they are widely applied to various fields,such as sterilization,water pollution control,air purification,etc.TiO2 and Cu2O are two of the most promising semiconductor catalysts.TiO2 catalytic technology is quite mature.However,for its structural characteristics,there is a big flaw in the light catalysis.First,the band gap of TiO2 is 3.2eV,leading to the utilization of solar energy which is less than 5%.Secondly,light electrons and holes generated by light is extremely easy to compound,which greatly reduces the·OH?·O2 concentration generated during the photoelectric reaction.The band gap of Cu2O is 2.2eV.Visible light can be absorbed directly,but the charge recombination rate is still quite high.Therefore,the photocatalytic degradation of the Cu2O was still under restrictions.In this paper,TiO2 and Cu2O were mixed with Mo2N and Au particles respectively,in order to increase their photocatalytic degradation.When modified TiO2 with Mo2N,Ti-titanate was put together with(NH4)6Mo7O24-HMT in aqueous ammonia solution,then calcinated at different temperatures to obtain TiO2-Ti/Mo2N,The results show:(1)In the Ti-NaOH-H2O2 system,nanowires formed on the surface of Ti particles become longer,and more sodium titanate composition formed with more reaction time.So 12h was choosed as the final reaction conditions.(2)Ti-titanate nanowires can be obtained from Ti-titanate sodium processing in HCl solution.The titanate nanowires has almost the same morphology as Ti-titanate sodium while the Na+is replaced by H+.(3)While investigated different calcination temperature on the crystal type of TiO2,it is found that with the increase of temperature,anatase gradually become to rutile.Besides,the effect of calcination temperature on Mo2N modifying situation was also investigated.The XRD and TEM results showed Mo2N modification is the best under 800 ?.In the case of Cu2O modified with Au particles,copper nanowires were firstly prepared,and the effects of different amines,Cu2+concentration,NaOH concentration on its morphology were studied.Then Cu2O@Cu was produced and the effects of reaction temperature,time and accessions of PVP on its morphology were also investigated.As a result,the following conclusions can be redraw(1)In the Copper nitrate-ethylenediamine-NaOH-PVP system,Cu nanowire with best results can be obtained with NaOH concentration of 15M,Cu2+ concentration of 0.001M at 80?.(2)When the reaction under 80? with PVP addition,after 8h Cu20@Cu with single component,uniform length and thickness was produced.(3)With the increase of gold chloride acid concentration,Cu2O@Cu modified by Au particles will become intense.While test in the photocatalytic performance of TiO2-Ti/Mo2N,Cu2O@Cu-Au composite catalyst,the following conclusion can be redraw:(1)After 800? calcination,TiO2-Ti/Mo2N photocatalytic degradation performance has been significantly improved,and the load of 5%of TiO2-Ti/Mo2N is best.(2)the photocatalytic degradation performance of Cu2O@Cu/Au was also significantly higher than that of Cu2O@Cu.And the performance increased with the increasing of Au particles. |
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