NiFe_2O_4/TiO_2纳米棒阵列薄膜光电化学性能和光催化性能研究

Photoelectrochemical and Photocatalytic Properties of NiFe_2O_4/TiO_2 Nanorod Arrays

用水热法制备一维有序纳米棒状TiO_2薄膜(TiO_2 NRAs),并采用浸渍沉积煅烧得到NiFe_2O_4/TiO_2 NRAs。借助SEM、TEM、XRD、Raman、XPS、UV-Vis等对样品的物相和形貌结构进行了表征,结果表明:NiFe_2O_4纳米颗粒均匀沉积在金红石相TiO_2 NRAs表面,使TiO_2光谱吸收范围拓展至可见光区。利用电化学工作站对其光电转换性能进行研究,发现NiFe_2O_4改性后的TiO_2在可见光下光电流响应显著增大,在电压-电流曲线和电流随时间开关灯变化中,NiFe_2O_4/TiO_2 NRAs的光电流密度分别是纯TiO_2 NRAs的12倍和8倍。NiFe_2O_4/TiO_2 NRAs可见光下降解偏二甲肼(UDMH)的效率是单纯TiO_2 NRAs降解率的3倍,并对光催化降解机理进行了探讨。

Highly ordered one-dimensional WiO2 nanorod arrays （TiO2 NRAs） film was prepared by hydrothermal method. Then through dipping deposition and calcination, the NiFe2O4 modified TiO2 NRAs （NiFe2O4/TiO2 NRAs） was obtained. To analyze the phase and morphology structure of the NiFe2O4/TiO2 NRAs, SEM, TEM, XRD, Raman spectra, XPS, and UV-Vis spectrophotoeter were used. The results showed that NiFe2O4 nanoparticles were uniformly deposited on the surface of rutile TiO2 NRAs, which led to a red shift in absorption spectrum. Considering the photo- electric conversion performance, it is discovered that photocurrent of NiFe2O4/TiO2 was greatly improved com- pared with that of bare TiO2 under visible light irradiation. The photocurrent density of NiFe2O4/TiO2 NRAs was 12 times that of bare TiO2 NRAs in the voltage-current curve, and 8 times that of bare TiO2 NRAs in the current changes with time switch light. Under visible light irradiation, degradation rate of UDMH by NiFe2O4/TiO2 NRAs was about 3 times as much as that of bare TiO2 NRAs. Furthermore, schematic of photocatalytic activity under visible light was explored.