Studies On Preparation And Photocatalytic Properties Of Cuprous Based Catalyst

With the development of the economic,the environment problem become more and more serious.The wastewater of industrial as one of the most common components of the environmental pollution,traditional processing technology is not very effective.So,many researchers are seeking for a highly efficient and continuable way of catalytic degradation of pollutant.Selective degradation reactions in mild reaction conditions are highly desirable for both economic and environmental reasons,then the photocatalytic degradation of pollutants technology has attracted a lot of attention and application due to the advantages of mild clean and sustainability.Besides,to seek a kind of high efficient photocatalyst is the key of the photocatalytic technology.Then copper?Cu?based materials have been studied extensively in the last decade.Cu₂O as a p-type semiconductor become a kind of novel and promising material for photocatalysis with absorption of visible light and low cost has been developed.But the performance of the single component of Cu₂O is limited and unstable and was oxidized easily to CuO which have not photocatalytic performance.Therefore.it is necessary to produce a modified catalyst to enhance the photocatalytic performance.A large number of studies have shown that the metal modified and morphology control can effectively increase the activity of photocatalyst.The main subject of the dissertation mainly investigated the preparation the Cu/Cu₂O core-hell submicro/nano catalysts by a fast chemical reduction method and discussed the formation mechanism and photocatalytic performance.In this paper,CuSO₄ was used as the precursor,hydrazine hydrate and ascorbic acid as reducing agent to synthesis of Cu/Cu₂O composite material by a liquid phase reduction method.The key of the approach relies on the EDTA-2Na ligands adhere to the surface of Cu particles by adsorptive action,then Cu²⁺ reacts with the EDTA-2Na ligands to form complex,which facilitates the approach of Cu²⁺ toward Cu metal surface and for the subsequent Cu₂O generation.As a result of the Cu²⁺-EDTA-2Na binding,which enables exclusive deposition of Cu₂O onto the Cu metal surface,hence the formation of Cu/Cu₂O core-shell particles.The characterizations of Cu/Cu₂O were carried out by BET,XRD,XPS and TEM.The results show the catalyst is a complex include Cu₂O and Cu,in which Cu₂O is predominant,the particle size is about 359.58±48.58nm and conform to the submicron level with high purity.To demonstrate the photocatalytic activities of the catalysts,the photocatalytic degradation of the Cr?VI?and RhB in a solution under visible-light irradiation by two different reaction system was choosen as the model reaction.The results show that the catalyst showed good degradation efficiency in both two different photocatalytic reaction system.Under the optimal conditions:150ml Cr?VI?solution,initial concentration 10mg/L,pH 3,150ml RhB solution,pH 7,initial concentration 20mg/L,catalyst 0.5g,H2O2 0.5ml,,the photodegradation efficiency could reach 91%and 81.14%,respectively and the reaction follows the first-order reaction kinetics.