Abstract Electrochemical hydrogen evolution reaction (HER) using non-precious compounds has gained substantial interest in the development of water electrolyzers. Herein, we report the synthesis of Copper sulfide (Cu2S) micro-hexagons via a hydrothermal method, followed by some of the important physiochemical characterizations and electrochemical measurements towards the HER. Cu2S micro-hexagons could catalyze the HER in both basic (1 M KOH) and acidic solutions (0.5 M H2SO4), corresponding to the extreme pH values of 14 and 0, respectively. As manifested from the polarization curve, Cu2S micro-hexagons required an overpotential of −330 mV and −312 mV to deliver a benchmark catalytic current density of 10 mA cm−2 in basic and acidic solutions, respectively. Furthermore, lower overpotentials are complemented with the prominent long-term stability of 24 h, as evident from chronopotentiometric analysis. The superior electrochemical performance of these Cu2S micro-hexagons demonstrates their promising suitability for water-splitting applications.

中文翻译：

---

硫化铜微六边形在极端pH条件下的析氢反应

摘要 使用非贵重化合物的电化学析氢反应 (HER) 在水电解槽的开发中引起了极大的兴趣。在此，我们报告了通过水热法合成硫化铜 (Cu2S) 微六边形，然后是一些重要的理化表征和电化学测量对 HER。Cu2S 微六边形可以在碱性 (1 M KOH) 和酸性溶液 (0.5 M H2SO4) 中催化 HER，分别对应于 14 和 0 的极端 pH 值。从极化曲线可以看出，Cu2S 微六边形需要 -330 mV 和 -312 mV 的过电位，以分别在碱性和酸性溶液中提供 10 mA cm-2 的基准催化电流密度。此外，从计时电位分析可以看出，较低的过电位与 24 小时的突出长期稳定性相辅相成。这些 Cu2S 微六边形的优异电化学性能表明它们非常适合水分解应用。