Fabrication of MnO2/TiO2 nano-tube arrays photoelectrode and its enhanced visible light photoelectrocatalytic performance and mechanism
Fabrication of MnO2/TiO2 nano-tube arrays photoelectrode and its enhanced visible light photoelectrocatalytic performance and mechanism
复制标题
MnO2/TiO2纳米管阵列光电极的制备及其增强可见光光电催化性能和机理
DOI：
10.1016/j.seppur.2017.08.007
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发表时间：
2017-12-22
影响因子：
8.6
通讯作者：
Cheng, Qingfeng
中科院分区：
文献类型：
--
作者：
Ma, Qiuling;Wang, Haitao;Cheng, Qingfeng
采用阳极氧化法和电沉积法制备了MnO 2/TiO 2纳米管阵列（MnO 2/TiO 2 NTAs）光电极，并对制备条件进行了优化。利用扫描电子显微镜（SEM）和X射线衍射仪（XRD）对所制备的光电极的结构进行了表征。通过紫外维斯漫反射光谱（UV维斯DRS）、光电流响应（PCR）和电化学阻抗谱（EIS）研究了其光吸收性能和光电化学性能。此外，这些光电极用于光电催化（PEC）降解亚甲基橙子（MO）在氙灯照射下。此外，通过清除效应和光致发光（PL）光谱进一步证实了增强PEG机制。结果表明，成功制备了内径为300 nm、厚度为60 nm的高度有序的TiO 2纳米管阵列光电极。此外，还发现这种新型的MnO 2/TiO 2 NTAs光电极不仅能使400 ~ 700 nm的光吸收峰红移到可见光区，而且能显著增强在PEC体系中起重要作用的羟基自由基的产生。结果表明，在优化条件下制备的MnO 2/TiO 2 NTAs光电极对MO具有较高的PEC降解活性，在外加电位（+ 2.0 V）下，1h内的降解效率可达95.2%。更重要的是，这些新的MnO 2/TiO 2 NTAs光电极被证明具有良好的稳定性和可重复使用性，将有很大的潜力，在废水处理中的有机污染物的降解。
MnO2/TiO2 nano-tube arrays (MnO2/TiO2 NTAs) photoelectrode was synthesized through anodization and electrodeposition, followed by the prepared conditions optimized. Subsequently, structures of the as-prepared photoelectrodes were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Besides, the light absorption capacities and photoelectrochemical (PECH) properties were investigated through UV vis diffuse reflectance spectrophotometer (UV vis DRS), photocurrent response (PCR) and electrochemical impedance spectroscopy (EIS). In addition, these photoelectrodes were used for the photoelectrocatalytic (PEC) degradation of methylene orange (MO) under Xenon lamp irradiation. Moreover, the enhanced PEG mechanism was further confirmed through scavengering effect and photoluminsecence (PL) spectra. Results presented that the highly ordered TiO2 nano-tube arrays photoelectrodes processed a uniform sizes of inner diameter of 300 nm and well thickness of 60 nm with MnO2 nanoparticles successfully deposited. Furthermore, it was found that these novel MnO2/TiO2 NTAs photoelectrodes could not only red-shift the light absorption to visible region between 400 nm and 700 nm, but also significantly enhance the generation of hydroxyl radicals COH) which played an important role in the PEC system. Noticeably, the MnO2/TiO2 NTAs photoelectrodes made in the optimized conditions exhibited much higher PEC activity toward MO degradation with the efficiency up to 95.2% within 1 h when external potential ( + 2.0 V) was applied. More importantly, these novel MnO2/TiO2 NTAs photoelectrodes proved to have excellent stability and reusability that would have great potentials for organic contaminants degradation in wastewater treatment.