Evaluating the Fe-doping effect on intermediate adsorption modulation for Co-based vanadates toward separation of hydrogen from water electrolysis

The optimization of intermediate adsorption is pivotal for enhancing the efficacy of catalysts in oxygen evolution reaction (OER). However, many Co-based catalysts exhibit excessive binding energy toward intermediates, thereby restricting the desorption process. To address this issue, we utilized the Co-based vanadates (CoV) as a model and observed that the incorporation of Fe can effectively mitigate the substantial accumulation of intermediates around the catalysts, achieving a balance between the adsorption and desorption. It can be attributed to the Fe-doping, which modulated the electronic structure of CoV, subsequently increasing the catalytic sites and intrinsic activity. As a result, the CoV-Fe exhibited a low overpotential of 260 mV at 20 mA cm −2 , which decreased by 82 mV compared to pristine CoV. Besides, the electrolyzer based on CoV-Fe maintained a low cell of 1.46 V for water splitting and held a considerable attenuation of 4.49 % after 200 h of long-term operation.