欠氧态二氧化钛纳米片阵列膜的制备及光催化性能研究

摘要

Oriented TiO2 nanosheet arrays with tunable doping concentration of oxygen vacancies were successfully fabricated via sodium borohydride liquid-phase reduction method,and were investigated as the photocatalyst for the degra-dation of methyl orange(MO). The results show that the photocatalytic activity of the oxygen-deficient nanosheet arrays could be significantly improved,and the optimal photo degradation rate for MO degradation was achieved to be 0.6 h-1, about 1.5 times higher than that of the unreduced nanosheet arrays. These promising results would be attributed to the com-bination of their oriented sheet-like morphology and a suitable doping concentration of oxygen vacancies,which can in-crease redox site of photocatalytic reaction,expand the light absorption range,and improve the conductivity.%将水热法制备的TiO2纳米片阵列膜,在50℃下经硼氢化钠(NaBH4)溶液液相还原后成功制得具有可调氧空位掺杂浓度的欠氧态TiO2纳米片阵列膜,并将其用作光催化剂降解甲基橙溶液(MO),考察样品的光催化增强性能.结果表明,与纯的TiO2纳米片阵列膜相比,欠氧态TiO2纳米片阵列膜的光催化活性显著提高,其最佳光降解MO溶液的速率为0.6 h-1,比纯的TiO2纳米片阵列膜在相同条件下的光降解速率高约1.5倍.分析认为,这种欠氧态TiO2纳米片阵列膜光催化活性的显著增强,应归因于TiO2纳米片阵列膜取向的片状分布式形貌和恰当的氧空位浓度二者的协同效应,前者可有效增加样品光催化反应的氧化还原位点,后者可明显拓宽其光吸收范围和提高光生载流子的传导性.