Hydrothermal Preparation and Photocatalytic Activity of Zn1-xCdxS Solid Solution Nanoparticles

Background: The current environment problem and energy crisis become two major bottleneck restricting the development of human. Photocatalytic technology is expected to become the effective approach to solve the problem of environment and energy. Since it is a "green" technology for removing toxic organic pollutants and photocatalytic degradation to solve the problem of environment. The aims of this paper are to introduce the new composite photocatalysts which improve photocatalytic activities and discuss reasons for mechanism of photocatalytic degradation. Methods: A series of Zn1-xCdxS solid solution nanoparticles were synthesized via the simple hydrothermal method. Then these samples were characterized by XRD, SEM, TEM, HRTEM, EDS and UV-vis techniques, while the photocatalytic activity of the samples for the degradation of RhB was evaluated under visible light illumination. Results: The band gaps of various Zn1-xCdxS were calculated. It was shown that when the redox power together with light absorption capacity in the Zn0.5Cd0.5S nanoparticles reach a balance which probably leads to a higher photocatalytic efficiency under visible light irradiation. When EDTA-2Na is added to the solution, the photocatalytic activities of all the Zn1-xCdxS photocatalysts have been greatly enhanced compared with no EDTA-2Na system. The result indicates that the addition of EDTA improves the separation efficiency of electrons and holes. Conclusion: The Zn1-xCdxS solid solution nanoparticles as visible-light induced photocatalyst was successfully synthesized by a simple hydrothermal method. We got the best ratio of ZnS to CdS which possessed an appropriate band-gap structure and exhibited the enhanced and highest photocatalytic activities under visible light irradiation. In addition, the enhancement of the photocatalytic performance of Zn1-xCdxS solid solution by the addition of EDTA-2Na may improve separation efficiency of electrons and holes.