Preparation And Performance Of Cuprous Oxide Photocatalytic Material

With social progress and rapid industrial development,energy depletion and environmental pollution are oncoming.In this regard,the development of environmental protection,clean,safe and sustainable energy is considered to be one of the challenges facing today’s society.However,in many current energy technologies,more researchers use solar-driven photocatalysts material for chemical and energy processes to degrade pollutants.However,to the current research on photocatalytic technology,the efficiency of photocatalyst is generally low,which affects the ability of photocatalyst to treat pollutants in wastewater and its practical use.Moreover,many existing photocatalysts show catalytic activity only under visible light irradiation,and have no photocatalytic activity in the absence of visible light irradiation.In our real life,most cases where photocatalysts are used to degrade pollutants are carried out continuously day and night.Therefore,the preparation and development of photocatalysts with a wider range of visible light,and make it work in the absence of light or darkness,which is of extraordinary significance for the expansion of the range of photocatalysis and the more effective use of visible light.Cuprous oxide(Cu2O)is a well-known material with a wide range of applications.It is an attractive photocatalyst due to its abundance,low toxicity and environmental compatibility.However,Cu2O has low photocatalytic activity.For example,Cu2O has low photocatalytic efficiency and is prone to photo corrosion caused by the composite of photogenerated electrons and holes,which hinders its wider application.Therefore,in order to obtain high quality Cu2O based photocatalysis,we compound Cu2O to improve its photocatalytic performance,and try to synthesize a catalyst with catalytic "memory" effect.The main contents of this paper are as follows:(1)Cu2O particles were successfully prepared by chemical reduction method in one step.The average size of Cu2O particles prepared was about 500 nm,and the degradation rate of MO solution was only 54.5%when exposed to visible light for 90 min.(2)CuO-Cu2O/Bi2O3 composite photocatalysts with different molar percentage of Bi2O3 were successfully prepared by chemical reduction method and hydrothermal method.Photocatalytic results showed that CuO-Cu2O/Bi2O3 composite photocatalyst than CuO-Cu2O and Cu2O catalytic ability under visible light irradiation,when bismuth mole percentage of 10.0%,CuO-Cu2O/Bi2O3 photocatalytic performance is best,50 mg CuO-CU2O/Bi2O3 in visible light irradiation after 300 min of 50 mL MO solution(20 mg·L-1)the degradation rate was 92.6%,CuO-Cu2O/Bi2O3 composite catalyst in use again after 5 times,for the degradation of MO at a rate of 80.6%,The results show that the prepared composite catalyst has good photocatalytic activity and stability.In the visible light irradiation after 5 h,in the dark environment,the removal rate of MO solution by CuO-Cu2O/Bi2O3 is 44.8%higher than that by Cu2O,it shows that the prepared material still has catalytic activity in the dark,making materials at night or under the condition of no light still have after irradiation catalytic "memory" ability.CuO-Cu2O/Bi2O3 composite is endowed with good post-irradiation catalytic"memory" effect.(3)After mixing Cu-Cu2O particles with TiO2 sol,a Cu-CuO/TiO2 composite photocatalyst was prepared by solvothermal method.When Cu-Cu2O/TiO2 composite particles in the TiO2 mass fraction of about 5%,after visible light irradiation for 30 min,20 mg,Cu-Cu2O/TiO2 composite particles to 20 mL MO solution(20 mg·L-1)the degradation rate of 93.7%,in Cu-Cu2O/TiO2 degradation test cycle after 4 cycles,the samples on the degradation rate of MO solution still remain above 90%,shows that the preparation of photocatalyst has good photocatalytic activity and stability.In visible light irradiation after 5 h,in the dark environment,the removal rate of MO solution by Cu-Cu2O/TiO2 is about 28.0%higher than that by Cu-Cu2O,it shows that the prepared material still has catalytic activity in the dark,so as to make the preparation of photocatalytic materials obtained after irradiation photocatalytic "memory" effect,make the photocatalyst in the dark under the condition of catalytic activity,for all-weather provides the experimental basis for the development of photocatalytic materials.(4)The ZnO/Bi2O3 photocatalyst was successfully prepared by chemical reduction method.The content of Bi2O3 in ZnO/Bi2O3 composites is adjusted by controlling the different molar percentage of NaBiO3.The results show that when the molar percentage is 5.5%,the ZnO/Bi2O3 composite prepared has the best catalytic performance in visible light,and the degradation rate of 50 mg ZnO/Bi2O3 reaches 92.1%in 180 min.After 5 times of recycling,the degradation rate of MO solution is still maintained at about 75.3%.These results indicate that Bi2O3 can effectively improve the photocatalytic activity of ZnO under visible light irradiation.