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电催化、光催化、光电催化等电化学技术以其高效、廉价、环保等特点被认为是一种极具前途的环境污染深度净化技术,在有机废水处理等方面得以广泛应用。本文借助电化学电量控制法制备了水钠锰矿电极,通过X射线衍射(XRD)、扫描电镜(SEM)表征其物相形貌,UV-Vis漫反射吸收谱结果表明水钠锰矿对300~600 nm波长范围可见光表现出良好吸收能力,计算其直接带隙约为2.14 e V,Mott-Schottky曲线计算其平带电位约1.15 V,0.1 mol/L Na2SO4介质中载流子浓度约为3.3×1019cm-3,是良好的可见光激发n型半导体材料。同时,本文以廉价高效的太阳能电池板取代了传统电化学工作站等外加电场设备,成功实现了协同强化水钠锰矿光电催化降解作用。协同作用下甲基橙60 min降解率为90.2%,效率远高于水钠锰矿光催化(2.2%)与电极电催化(33.6%)作用,强化了水钠锰矿光电催化降解反应,节省能耗的同时显著提高了降解效率。批次循环降解实验表明第4轮降解率(86.8%)较之第1轮(90.3%)降低程度<5%,表明其具有良好长时间运行稳定性。
Electrochemical, photocatalysis and photoelectrocatalytic electrochemical techniques are considered as a promising technology for the deep purification of environmental pollution due to their high efficiency, low cost and environmental protection. They are widely used in organic wastewater treatment and other fields. In this paper, birnessite electrode was prepared by electrochemical charge control method. The phase morphology was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results of UV-Vis diffuse reflectance absorption spectroscopy showed that birnessite has the best performance for 300-600 The visible bandgap shows good absorption in the wavelength range of nm. The calculated direct band gap is about 2.14 eV. The Mott-Schottky curve calculates the band potential of about 1.15 V. The carrier concentration in 0.1 mol / L Na2SO4 is about 3.3 × 10 19 cm -3, is a good visible light excited n-type semiconductor material. At the same time, this paper replaced the traditional electrochemical workstation and other external electric field equipment with cheap and efficient solar panels, and succeeded in the synergistic enhancement of photoelectrocatalytic degradation of birnessite. Under the synergistic action, the degradation rate of methyl orange for 60 min was 90.2%, which was much higher than that of birnessite (2.2%) and electrode electrocatalysis (33.6%), which enhanced the photoelectrocatalytic degradation reaction of birnessite and saved energy While significantly increasing the degradation efficiency. Batch cycle degradation experiments showed that the degradation rate of the fourth round (86.8%) was less than 5% compared with the first round (90.3%), indicating that it has good long-term operation stability.