Application of TiO2 nanotube arrays for bipolar photocatalytic fuel cells
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摘要: 光催化燃料电池技术(Photocatalytic Fuel Cell, PFC)结合了光催化技术与燃料电池技术, 可以同时进行降解废水与发电, 对污水处理具有重要意义. 探索了TiO2纳米管阵列(TiO2 Nanotubes Arrays, TNAs)光阳极制备工艺对其形貌结构的影响; 通过扫描电子显微镜(Field Emission Scanning Electron Microscope, FESEM)证实了电解时间与TNAs管长正相关; 与Cu2O光阴极组合得到的具有更强光催化活性系统证实了 PFC 协同效应的存在, 最佳的电解工艺为4 h, 该工艺制备的电极对双氯酚酸光催化降解率在 2 h内为79%; 对 3 种标准物的分析说明, 在较高的浓度范围内, 通过 PFC 外电路的净电荷量与化学需氧量(Chemical Oxygen Demand, COD)线性相关, 而随着降解进行, 传质过程减弱, 两者之间的相关性减弱.Abstract: Photocatalytic fuel cell (PFC) technology is a combination of photocatalytic technology and fuel cell technology, which can degrade wastewater and generate electricity at the same time. The influence of the preparation process for photoanodes of TiO2 Nanotube Arrays (TNAs) on its morphology and structure was explored; a positive correlation between the electrolysis time and the tube length of TNAs was confirmed by a Field Emission Scanning Electron Microscope (FESEM). We can combine TNAs with Cu2O photoelectrodes to obtain a system with stronger photocatalytic activity, confirming the existence of a PFC synergistic effect. The optimal electrolysis process was 4 h, and the photocatalytic degradation rate of the electrode prepared by this process was more than 79% within 2 h. Analysis of the three standards showed an excellent linear correlation between the photocurrent of PFC and the chemical oxygen demand (COD); as the degradation proceeds, the mass transfer process is reduced and the correlation between the two is weakened.
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图 6 (a) TNAs电极、Cu2O电极与TNAs-Cu2O PFC光催化效果; (b) 不同电解时间的TNAs光阳级PFC的降解效率; (c) 不同DCF浓度对TNAs-Cu2O双极PFC的影响; (d)TNAs-Cu2O重复性
Fig. 6 (a) PFC performance of TNA anode, Cu2O cathode and TNA-Cu2O PFC; (b) PFC performance of TNA-Cu2O PFC with different electrolysis times; (c) PFC performance of TNA-Cu2O PFC with different fuel concentrations; and (d) repeatability of TNAs-Cu2O
表 1 不同电解时间下管长、管直径、纳米管的比表面积以及光催化性能
Tab. 1 The length, diameter, specific surface area, and photocatalytic properties of the nanotubes studied under different electrolysis times
管长/μm 管内径/nm 比表面积/(m2·g–1) DCF降解率/% TNAs-1 0.59 77 178.7 41 TNAs-2 1.2 84 266.4 52 TNAs-3 1.6 90 304.8 57 TNAs-4 2.0 98 340.1 79 TNAs-5 坍塌 坍塌 21.2 25 -
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