Synthesis And Properties Of Visible Photocatalysts For Metal Sulfide Composites

In recent years, due to the narrow bandgap metal sulfide, so it can absorb visible light, which has attracted wide attention. However, it also has a series of disadvantages, such as: low stability, prone to light rot thus limiting its application. So we study the synthesis of a different metal sulfide heterojunction, by constructing a heterojunction can broaden their band gap, improve the range of light absorption, and can successfully overcome the above drawbacks, the catalyst is visible recent new developments trend. The main contents of this paper are as follows:1. In this study, sea-urchin shaped Bi2S3/CdS hierarchical heterostructures are successfully synthesized via a simple and convenient one-pot route. The product is mainly composed of Bi2S3 nanorods and CdS nanoparticles grown on their surfaces. The formation mechanism was proposed based on the evolution of morphology as a function of solvothermal time, which involves the fast formation of initial sea-urchin shaped Bi2S3 nanoflowers, followed by the gradual growth of numerous CdS nanoparticles onto the surface of Bi2S3 namoflowers. The Bi2S3/CdS heterostructures display much higher photocatalytic activity towards the organic pollutants degradation compared with single Bi2S3 or CdS, which can be attributed to the synergistic effect of CdS nanoparticles and Bi2S3 nanoflowers.2. Hierarchical Ag/Ag2S/CuS ternary heterostructure has been obtained through cationic exchange between as-prepared CuS nanoflowers and AgNO3(synthesized under solvothermal condition) and subsequent in situ UV light reduction. The prepared CuS not only provides reactive sites for in situ ion exchange with Ag+, but also performs as clapboards to spatially separate Ag2 S nanoparticles, avoiding their excess aggregation. After exposure to UV light, uniform Ag/Ag2S/CuS ternary nanocomposites are obtained. In the composite, both Ag and Ag2 S are in direct contact with CuS, and Ag nanocrystals are mainly deposited on the surface of Ag2 S nanparticles. The prepared ternary heterostructure composite exhibited significant degradation ability for the elimination of some more hazardous pollutants under visible light irradiation, which is much higher than that of either the single component or two components. Moreover, the resultant ternary composites possess excellent stability.3. By the in situ solvothermal method growth, a novel ZnIn2S4/g-C3N4 nanosheets composite has been obtained. The introduction of g-C3N4 in the system is equivalent to the an electron collection means, can provide a good conductor of photogenerated electron transfer. So compared with the pure ZnIn2S4 photocatalyst, our prepared ZnIn2S4/g-C3N4 catalyst showed excellent performance in photolytic hydrogen production and also showed excellent cycle stability of hydrogen production.