以煤系高岭土（CK）、双氰胺为原料，采用热聚合法制得g-C₃N₄/煤系高岭土（g-C₃N₄/CK）复合材料，并用于光催化氧化As （Ⅲ）。通过XRD、SEM、UV-DRS、PL光谱等分析手段对g-C₃N₄/CK复合材料进行表征。结果表明，g-C₃N₄与CK复合后改善了g-C₃N₄片层团聚状态，抑制了光生电子和空穴的复合，具有更强的光催化氧化As （Ⅲ）能力。在所构造的复合催化剂中，g-C₃N₄/CK-15%光催化氧化As （Ⅲ）效果最佳，在光照210 min的条件下，As （Ⅲ）的氧化率可达90.54%；g-C₃N₄/CK-15%稳定性较佳，循环使用4次后仍有较强的光催化氧化能力。机理分析结果表明，空穴和超氧自由基是As （Ⅲ）氧化的主要活性基团。

Novel g-C₃N₄/coal-bearing kaolin (g-C₃N₄/CK) composites are prepared by thermal polymerization method using coal-bearing kaolin (CK) and dicyandiamide as raw materials,and used for the photo-catalytic oxidation of As(Ⅲ).The properties of the prepared composites samples are characterized through X-ray diffraction,scanning electron microscopy,UV-visible diffuse reflectance spectroscopy and photoluminescence spectroscopy.The results show that compared with pure g-C₃N₄,the prepared g-C₃N₄/CK composites exhibit an enhanced ability in photo catalytic oxidation of As (Ⅲ),which may be due to that the composition between g-C₃N₄ and CK has improved the aggregation state of g-C₃N₄ lamellae,thus suppressing the recombination between electron and hole.Among the prepared composite catalysts,g-C₃N₄/CK-15% composite exhibits the best photo catalytic activity,over which the photo catalytic oxidation rate of As(Ⅲ) can reach 90.54% after 210 min of visible light illumination.Moreover,g-C₃N₄/CK-15% composite has good reusability.After being used for 4 cycles,the photo catalytic ability of g-C₃N₄/CK-15% remains strong.Mechanism analysis shows that photo generated holes and superoxide radicals are the main active species responsible for the oxidation of As(Ⅲ).

杨权成(1986-),男,博士,讲师,主要从事环境纳米材料和固废综合利用研究,yangquancheng@126.com