.cds / Zno Photocatalytic Decomposition Of Hydrogen Sulfide

CdS/ZnO composite photocatalysts which were treated by calcinations, hydrothermal synthesis and microwave-hydrothermal synthesis had been prepared by sol-gel and precipitation method. The above-prepared photocatalysts had been characterizaed by XRD, UV-Vis and SEM to analysis their structure and surface morphology. The effect of reaction temperature, reaction time and percentage of CdS on structure of CdS/ZnO and their photocatalytic properties on H2 production had been investigated.The optimum preparation condations for CdS/ZnO treated by calcinations had been obtained as follows: ammoia was used as peptizing agent, the percentage of CdS was 50%, the reaction temperature and calcinations temperature were 30℃, 400℃, and ultrasonic time was 30min. CdS(50)/ZnO-400 prepared by the above condations had been characterized by XRD, UV-Vis and SEM, and the result showed that CdO was generated during calcinations process in air, the catalyst after calcinations was hexagonal structure, and the absorption scope of CdS/ZnO increased. The photocatalyst had been used for the photocatalytic decomposition of H2S to produce H2 and the H2 production rate was 5 mmol/g·h which was higher than that of singel CdS and ZnO.The optimum preparation condations for CdS/ZnO treated by hydrothermal method had been obtained as follows: Na2S was used as sulfur source, the percentage of CdS was 50%, and the hydrothermal temperature was 240℃. CdS (50)/ZnO-240 photocatalyst was hexagonal structure, the absorption edge shifted to visible region, and the partical size was small. The photocatalyst had been used for the photocatalytic decomposition of H2S to produce H2 and the H2 production rate was 7.3 mmol/g·h.The optimum preparation condations for CdS/ZnO treated by microwave-hydrothermal method had been obtained as follows: the reaction time was 60min, microwave temperature was 210℃, and the percentage of CdS was 30%. The XRD characterization result of CdS(30)/ZnO-210 showed that only characteristic peaks of CdS had been observed and there were no peaks of ZnO. The UV-Vis characterization result showed that the absorption edge of CdS(30)/ZnO-210 was 500nm. It could be seen from SEM image that the catalyst particles were well dispered and the size was about 20nm. The photocatalyst had been used for the photocatalytic decomposition of H2S to produce H2 and the H2 production rate was 5.3 mmol/g·h.