Gan Weijiang, Mathi Selvam, Li Jingting, Ipadeola Adewale K, Deng Jianqiu, Abdullah Aboubakr M, Balogun M-Sadeeq, Wang Zhongmin
State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, Guangxi 530007, China.
College of Materials Science and Engineering, Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy, Hunan University, Changsha, 410082, People's Republic of China.
Nanoscale. 2025 May 23;17(20):12660-12672. doi: 10.1039/d5nr00801h.
Strategic modulation of the electronic structure and surface chemistry of electrocatalysts is crucial for achieving highly efficient and cost-effective bifunctional catalysts for water splitting. This study demonstrated the strategic incorporation of redox-active elements (vanadium (V) and iron (Fe)) to optimize the catalytic interface of mixed-valence cobalt-based nanowires (CoN and CoP), which enhanced their hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic activity. Experimental and theoretical analyses revealed that the dual-cation doping increased the surface area and optimized the electronic structure of the nanowires, which promoted rapid water dissociation, favoured hydrogen adsorption kinetics, and stabilized the oxygen intermediates. Consequently, the V,Fe-CoN and V,Fe-CoP nanowire electrocatalysts achieved low overpotentials of 55/251 and 63/265 mV for HER/OER at 10 mA cm in 1 M KOH electrolyte, respectively, outperforming their pristine and single-cation-doped counterparts. The alkaline overall water-splitting devices assembled based on these bifunctional catalysts required an overall voltage of only 1.64 V and 1.66 V at 100 mA cm and also demonstrated excellent durability. This work provides valuable insights into enhancing transition metal-based catalysts through the incorporation of redox-active elements for efficient water splitting.
对电催化剂的电子结构和表面化学进行策略性调控对于实现用于水分解的高效且经济高效的双功能催化剂至关重要。本研究展示了氧化还原活性元素（钒（V）和铁（Fe））的策略性引入，以优化混合价态钴基纳米线（CoN和CoP）的催化界面，从而增强其析氢反应（HER）和析氧反应（OER）的催化活性。实验和理论分析表明，双阳离子掺杂增加了纳米线的表面积并优化了其电子结构，促进了水的快速解离，有利于氢吸附动力学，并稳定了氧中间体。因此，V,Fe-CoN和V,Fe-CoP纳米线电催化剂在1 M KOH电解液中，在10 mA cm下HER/OER的过电位分别低至55/251和63/265 mV，优于其原始和单阳离子掺杂的对应物。基于这些双功能催化剂组装的碱性全水分解装置在100 mA cm下仅需1.64 V和1.66 V的全电压，并且还表现出优异的耐久性。这项工作为通过引入氧化还原活性元素来增强过渡金属基催化剂以实现高效水分解提供了有价值的见解。
