Study On Synthesis,Modification And Photocatalytic Performance Of Cu₂O

Cu₂O is a p-type semiconductor photocatalytic material with a band gap of 2.17e V,it has the advantages of non-toxicity,low price and high activity.A photocatalyst with excellent performance can be prepared by modification treatment.Cu₂O with different morphologies were synthesized by hydrothermal method in this paper.Then,the ion doped Cu₂O materials and g-C₃N₄/Cu₂O composite materials were prepared.The morphologies,microstructures and photocatalytic performance of the synthesized products were carried out.By analyzing the effect of process parameters on the morphology of synthesized products,the optimal hydrothermal synthesis and modification process of Cu₂O were determined.By testing nitrogen adsorption desorption,the specific surface area and pore size distribution of the synthesized products were characterized.By testing the photocatalytic performance of the synthesized products for methylene blue（MB）,methyl orange（MO）and rhodamine B（RhB）,the degradation ability of organic dyes was evaluated,and the photocatalytic mechanism was clarified..The results show that the hydrothermal synthesis process has a great influence on the morphology of Cu₂O particles.The sizes of Cu₂O particles are different when the reaction temperature is low and the reaction time is short.The Cu₂O particles will become larger and the dispersion will become worse when the reaction temperature is too high and the reaction time is too long.When the content of NaOH and ascorbic acid is too little or too much,the Cu₂O particles will have irregular shape,different sizes and poor dispersion.The Cu₂O particles with a diameter of about 0.8-1.4μm were synthesized at140°C for 5 h using 5 mmol CuSO₄·5H₂O,30 mmol NaOH,and 1 mmol ascorbic acid as the source materials.At this time,the morphologies of the Cu₂O are the best.The shape of the Cu₂O is polyhedron,and the specific surface area is 1.44 cm³g^-1.Under the conditon of 500 W mercury lamp for 120 mins,the degradation rates of RhB,MB,and MO were 70.0%,61.9%,and 46.1%,respectively.The particle sizes of the Cu₂O become smaller and the photocatalytic performance is getting better by doping with Zn（CH₃COO）₂·2H₂O.The product has high purity and good crystallinity.Compared with undoped Cu₂O,the specific surface area becomes larger,and the photocatalytic degradation rates of RhB,MB and MO are increased by21.9%,22.4%and 5.6%,respectively.The particle size of Cu₂O was refined and the photocatalytic performance was improved when using g-C₃N₄as template.The specific surface area of g-C₃N₄/Cu₂O composites is 42.75 cm³g^-1.when irradiated by 500 W mercury lamp for 120 mins,the degradation rates of RhB,MB and MO are 73.9%,64.0%and 52.5%,respectively,which is better than single g-C₃N₄and Cu₂O.This paper has 36 figures,6 tables and 96 references.