Dong Qinglong, Zang Lijie, Sun Dipeng, Xu Yongqi, Zhao Dong, Lyu Xiao
School of Materials Science and Engineering, Shenyang Ligong University, Shenyang 110159, China.
School of Materials Science and Engineering, Shenyang Ligong University, Shenyang 110159, China.
J Colloid Interface Sci. 2025 Nov 15;698:138053. doi: 10.1016/j.jcis.2025.138053. Epub 2025 Jun 2.
Electrocatalytic water splitting for hydrogen production is recognized as one of the most advanced sustainable new energy resources. The design of bifunctional electrocatalysts for water splitting at the two electrodes, which involved in anodic oxygen evolution reaction (OER) and cathodic hydrogen evolution reaction (HER) is crucial for the development and utilization of water splitting. Herein, the sulfur (S)-doping defective CuCoO (S-r-CCO) electrocatalyst was synthesized by doping S ions into oxygen-defect-riched CuCoO as bifunctional electrocatalysts for both OER and HER in this work. Due to the synergistic effect by S-doping and oxygen vacancy strategy, the S-r-CCO electrocatalyst presented an enhanced electrocatalytic performance. S-r-CCO electrocatalyst achieved a low overpotential of 248 mV at a current density of 10 mA cm with Tafel slopes of 37.7 mV dec for OER and an overpotential of 113 mV at a current density of 10 mA cm with Tafel slopes of 76.5 mV dec for HER. In addition, the assembled S-r-CCO||S-r-CCO electrodes only required a cell voltage of 1.78 V to achieve a current density of 10 mA cm, which is superior to that of the commercial IrO||Pt/Ti electrolyzer (1.93 V) for anion exchange membrane (AEM) electrolyzer. The density functional theory (DFT) result illustrated that the synthesized massive oxygen vacancies, which provided more sites for trapping S atoms to form Co(Cu)-S coordination sites, efficiently regulated the electronic structure of S-r-CCO and improved its electrical conductivity. In addition, the introduction of S could stabilize the catalytic activity for oxygen vacancies, which greatly improved the catalytic stability of S-r-CCO electrocatalyst. Therefore, this study provides a new path for the design of effective non-noble metal bifunctional electrocatalysts for electrocatalytic water splitting.
电催化水分解制氢被认为是最先进的可持续新能源之一。用于两电极水分解的双功能电催化剂的设计，涉及阳极析氧反应（OER）和阴极析氢反应（HER），对于水分解的开发和利用至关重要。在此，通过将硫（S）离子掺杂到富含氧缺陷的CuCoO中，合成了硫（S）掺杂缺陷型CuCoO（S-r-CCO）电催化剂，作为用于OER和HER的双功能电催化剂。由于S掺杂和氧空位策略的协同作用，S-r-CCO电催化剂表现出增强的电催化性能。S-r-CCO电催化剂在电流密度为10 mA cm时，OER的过电位低至248 mV，塔菲尔斜率为37.7 mV dec；在电流密度为10 mA cm时，HER的过电位为113 mV，塔菲尔斜率为76.5 mV dec。此外，组装的S-r-CCO||S-r-CCO电极在电流密度为10 mA cm时仅需1.78 V的电池电压，这优于用于阴离子交换膜（AEM）电解槽的商业IrO||Pt/Ti电解槽（1.93 V）。密度泛函理论（DFT）结果表明，合成的大量氧空位为捕获S原子形成Co（Cu）-S配位位点提供了更多位点，有效调节了S-r-CCO的电子结构并提高了其电导率。此外，S的引入可以稳定氧空位的催化活性，大大提高了S-r-CCO电催化剂的催化稳定性。因此，本研究为设计用于电催化水分解的有效非贵金属双功能电催化剂提供了一条新途径。
