Cupric oxide (CuO) is a promising candidate as a photocathode for visible‐light‐driven photo‐electrochemical (PEC) water splitting. However, the stability of the CuO photocathode against photo‐corrosion is crucial for developing CuO‐based PEC cells. This study demonstrates a stable and efficient photocathode through the introduction of graphene into CuO film (CuO:G). The CuO:G composite electrodes are prepared using graphene‐incorporated CuO sol–gel solution via spin‐coating techniques. The graphene is modified with two different types of functional groups, such as amine (NH₂) and carboxylic acid (COOH). The COOH‐functionalized graphene incorporation into CuO photocathode exhibits better stability and also improves the photocurrent generation compare to control CuO electrode. In addition, COOH‐functionalized graphene reduces the conversion of CuO phase into cuprous oxide (Cu₂O) during photo‐electrochemical reaction due to effective charge transfer and leads to a more stable photocathode. The reduction of CuO to Cu₂O phase is significantly lesser in CuO:G‐COOH as compared to CuO and CuO:G‐NH₂ photocathodes. The photocatalytic degradation of methylene blue (MB) by CuO, CuO:G‐NH₂ and CuO:G‐COOH is also investigated. By integrating CuO:G‐COOH photocathode with a sol–gel‐deposited TiO₂ protecting layer and Au–Pd nanostructure, stable and efficient photocathode are developed for solar hydrogen generation.

中文翻译：

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用于实现氢经济的纳米工程先进材料：用于高效太阳能制氢的功能化石墨烯掺入氧化铜催化剂。

氧化铜（CuO）是作为可见光驱动光电化学（PEC）水分解的光电阴极的有前途的候选者。然而，CuO 光电阴极的抗光腐蚀稳定性对于开发 CuO 基 PEC 电池至关重要。这项研究通过将石墨烯引入 CuO 薄膜 (CuO:G) 展示了一种稳定高效的光电阴极。CuO:G 复合电极是通过旋涂技术使用掺有石墨烯的 CuO 溶胶-凝胶溶液制备的。石墨烯被两种不同类型的官能团修饰，例如胺（NH ₂）和羧酸（COOH）。与对照 CuO 电极相比，将  COOH功能化石墨烯纳入 CuO 光电阴极表现出更好的稳定性，并且还提高了光电流的产生。此外，由于有效的电荷转移， COOH官能化石墨烯在光电化学反应过程中减少了CuO相向氧化亚铜（Cu ₂ O）的转化，从而形成更稳定的光电阴极。与CuO 和 CuO :G-NH ₂光电阴极相比，CuO:G-COOH 中 CuO 向 Cu ₂ O 相的还原明显较少。还研究了CuO、CuO:G-NH ₂和 CuO:G-COOH对亚甲基蓝 (MB) 的光催化降解。通过将CuO:G-COOH光阴极与溶胶-凝胶沉积的TiO ₂保护层和Au-Pd纳米结构相结合，开发出稳定高效的用于太阳能制氢的光阴极。