一步温和水热法制备具有改善光催化活性和稳定性的碳包覆CdS纳米粒子

首次报道在130oC低温条件下，以乙酸镉和葡萄糖分别作为镉源和碳源，硫脲同时充当硫源和葡萄糖水热碳化的催化剂，通过一步水热碳化法制备了碳包覆的CdS (CdS@C)纳米材料。与相同条件下制备的纯CdS相比，合成的CdS@C粒子具有更小的粒子尺寸、良好的分散性以及更均匀的粒子分布。而且，葡萄糖在水热碳化过程中能够促使CdS优先形成立方晶相。此外，粒子表面的碳物种能拓宽CdS的可见光吸收范围，稍微降低它的带隙能，减缓CdS的光生电子-空穴对的复合和光腐蚀。因此，它能改善CdS在可见光辐射下催化氧化降解甲基橙的活性和稳定性。

Mild,one-step hydrothermal synthesis of carbon-coated CdS nanoparticles with improved photocatalytic activity and stability

Carbon-coated CdS (CdS@C) nanoparticles were conveniently prepared by a one-step hydrothermal carbonization method at temperature as low as 130 °C, in which cadmium acetate and glucose were used as the cadmium and carbon sources, respectively, and thiourea was used as the sulfur source and catalyst for the hydrothermal carbonization of glucose. The prepared CdS@C particles possess a smaller size, better dispersion, and more uniform distribution than pure CdS particles prepared under the same conditions. Furthermore, the hydrothermal carbonization of glucose easily induces the prior formation of metastable cubic CdS crystals. In addition, the carbonaceous species coated on the surface of CdS expands the range of absorption light and slightly decreases the band gap of CdS, as well as reduces the recombination of the photogenerated electron-hole pairs of CdS and its photo-oxidative corrosion, which can improve the photocatalytic activity and stability of CdS for the photo-oxidative degradation of methyl orange in aqueous solution under visible light irradiation.