N掺杂C包覆NaTaO3复合材料制备及其可见光催化性能

Preparation and visible light catalytic performance of N-doped C coated NaTaO3 composites

以五氯化钽(TaCl5)、乙酸钠为原料,三聚氰胺为N源,十六烷基三甲基溴化铵(CTAB)和聚乙烯吡咯烷酮(PVP)为表面活性剂,通过溶胶-凝胶法制备了N掺杂C包覆NaTaO3复合材料。采用XRD、TEM、XPS、UV-Vis DRS等对样品进行表征,以罗丹明B(RhB)溶液为目标降解物,测试了不同N比例掺杂的复合材料的吸附性能和光催化性能。结果表明,加入的CTAB和PVP经过N2保护的热处理后在NaTaO3周围形成超薄的碳膜,不仅限制NaTaO3粒径增长,而且提高复合材料对目标污染物的吸附性。N掺杂C包覆NaTaO3复合材料具备良好的可见光催化活性,其中三聚氰胺与TaCl5的摩尔比n为1.5时,制备的N掺杂C包覆NaTaO3复合材料可见光催化效率最高,暗中吸附80 min、可见光照8 h时,RhB的去除率为96.46%,其光催化反应过程符合准一级反应动力学规律。

The N-doped C coated NaTaO3 composite was prepared through sol-gel method by using tantalic chloride(TaCl5)and sodium acetate as raw materials,melamine as N sources,cetyl trimethyl ammonium bromide(CTAB)and polyvinylpyrrolidone(PVP)as surfactant.The synthesized sample was characterized in detail by XRD,TEM,XPS and UV-Vis DRS.The dye rhodamine B(RhB)was used as a model contaminant to evaluate the adsorption and photocatalytic activity of N-doped carbon coated NaTaO3.The results indicate that CTAB and PVP form ultra-thin carbon film around NaTaO3,which not only limits the growth of NaTaO3 particles,but also improves the adsorbability to target pollutants.The composites with tripolynitrile amines to TaCl5 molar ratio n=1.5 have the best visible light catalytic performance and the removal ratio of RhB achieves 96.46%under dark adsorption for 80 min and irradiation for 8 h.The photodegradation of RhB is in accordance with the pseudo first order reduction kinetics model.