Effects of bath pH on structural and electrochemical performance of Cu₂O

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• 作者：Guangli Li ; Yaohan Huang ; Qingfei Fan ; Meili Zhang ; Qi Lan ; Ximei Fan…
• 关键词：Cu2O films ; Potentiostatic deposition ; Diffusion coefficient ; pH
• 刊名：Ionics
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：22
• 期：11
• 页码：2213-2223
• 全文大小：2,070 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Electrochemistry
  Materials Science
  Physical Chemistry
  Condensed Matter
  Renewable Energy Sources
  Electrical Power Generation and Transmission
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1862-0760
• 卷排序：22

文摘

Well-defined cuprous oxides (Cu₂O) with different morphologies were successfully deposited on fluorine-doped tin oxide (FTO)-covered glass substrates by potentiostatic deposition. The effect of the pH values on the crystal morphologies of Cu₂O was studied. The as-prepared products were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and UV-visible spectroscopy. The typical XRD patterns revealed that all Cu₂O thin films were pure Cu₂O phase. Different crystal morphologies of Cu₂O could be obtained by varying pH. The Cu₂O thin film was composed of a large number of star-like shape grains with the pH of 4.8. With a further increase of the pH, the Cu₂O film showed the uniform dendrite morphology. LSV uncovered that E_R (reduction potential of Cu2+ to Cu+) increased with the pH value enlargement. According to the EIS, diffusion coefficient of Cu2+ ion was reduced with the increase of the pH. The UV-vis absorption spectra revealed that the broad absorption peaks were from 300 to 500 nm and the evaluated band gap of the films was tunable in the range of 2.02–2.67 eV, with the variation of the pH values. According to the experiment and relevant literatures, the probable electrodeposition mechanism of the Cu₂O was discussed.