Abstract The field of TiO2 photo-electrode synthesis is fast-growing, due to the competitive performance of TiO2 in light-harvesting applications such as photo-electrochemical water splitting. Real-time monitoring of TiO2 nanotube array (NTA) synthesis is critical for reproducibility in a production chain of identical photo-electrodes. By analysing the transient stage of a current density signal, this work demonstrates the expected responses to changes in anodic voltage and electrolyte content. Seven titanium foil substrates were anodized in an anhydrous polar organic electrolyte mixed with NH4F as the etching agent. The current density increased with voltage and the first steady state of the transient, that indicates the onset of chemical dissolution, was reached earlier when using higher quantities of NH4F. Changes in film pore size and morphology of un-etched regions of the NTAs correlated with the growth parameters. A flowchart that can be used to formulate set points, in order to detect deviations from desired anodization parameters, and hence declare a sample rejected or otherwise, is proposed for applications requiring a closed-loop control system to accurately monitor the anodic growth of TiO2 in ethylene glycol + NH4F electrolytes.

中文翻译：

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TiO2纳米管阳极生长过程中合成参数变化的电流密度瞬态响应

摘要 由于二氧化钛在光电化学分解水等捕光应用中的竞争性能，二氧化钛光电极合成领域发展迅速。TiO2 纳米管阵列 (NTA) 合成的实时监控对于相同光电极生产链中的重现性至关重要。通过分析电流密度信号的瞬态阶段，这项工作展示了对阳极电压和电解质含量变化的预期响应。在混合有 NH4F 作为蚀刻剂的无水极性有机电解质中对七个钛箔基材进行阳极氧化。电流密度随着电压的增加而增加，并且当使用较高量的 NH4F 时，会更早地达到瞬态的第一个稳态，这表明化学溶解的开始。NTAs 未蚀刻区域的薄膜孔径和形态的变化与生长参数相关。可用于制定设定点的流程图，以便检测与所需阳极氧化参数的偏差，从而宣布样品被拒绝或以其他方式拒绝，适用于需要闭环控制系统以准确监控 TiO2 阳极生长的应用。乙二醇 + NH4F 电解质。