Helal Gouda, Xu Zhenhang, Zuo Wei, Yu Yueying, Liu Jinyan, Su Hongping, Xu Jianxin, Li Houbin, Cheng Gongzhen, Zhao Pingping
College of Chemistry and Molecular Sciences, Wuhan University Wuhan Hubei 430072 P. R. China
Faculty of Science, Benha University Benha City Kalyobiya Egypt.
RSC Adv. 2024 Mar 27;14(15):10182-10190. doi: 10.1039/d4ra00146j. eCollection 2024 Mar 26.
Transition metal-based catalysts are commonly used for water electrolysis and cost-effective hydrogen fuel production due to their exceptional electrochemical performance, particularly in enhancing the efficiency of the oxygen evolution reaction (OER) at the anode. In this study, a novel approach was developed for the preparation of catalysts with abundant active sites and defects. The MoCoFe-phosphide catalyst nanosheets were synthesized using a simple one-step hydrothermal reaction and chemical vapor deposition-based phosphorization. The resulting MoCoFe-phosphide catalyst nanosheets displayed excellent electrical conductivity and a high number of electrochemically active sites, leading to high electrocatalytic activities and efficient kinetics for the OER. The MoCoFe-phosphide catalyst nanosheets demonstrated remarkable catalytic activity, achieving a low overpotential of only 250 mV to achieve the OER at a current density of 10 mA cm. The catalyst also exhibited a low Tafel slope of 43.38 mV dec and maintained high stability for OER in alkaline media, surpassing the performance of most other transition metal-based electrocatalysts. The outstanding OER performance can be attributed to the effects of Mo and Fe, which modulate the electronic properties and structures of CoP. The results showed a surface with abundant defects and active sites with a higher proportion of Co active sites, a larger specific surface area, and improved interfacial charge transfer. X-ray photoelectron spectroscopy (XPS) analysis revealed that the catalyst's high activity originates from the presence of Mo/Mo and Co/Co redox couples, as well as the formation of active metal (oxy)hydroxide species on its surface.
基于过渡金属的催化剂因其优异的电化学性能，特别是在提高阳极析氧反应（OER）效率方面的性能，常用于水电解和具有成本效益的氢燃料生产。在本研究中，开发了一种制备具有丰富活性位点和缺陷的催化剂的新方法。采用简单的一步水热反应和基于化学气相沉积的磷化反应合成了MoCoFe-磷化物催化剂纳米片。所得的MoCoFe-磷化物催化剂纳米片表现出优异的导电性和大量的电化学活性位点，从而导致OER具有高电催化活性和高效动力学。MoCoFe-磷化物催化剂纳米片表现出显著的催化活性，在电流密度为10 mA cm时实现OER的过电位低至仅250 mV。该催化剂还表现出43.38 mV dec的低塔菲尔斜率，并在碱性介质中对OER保持高稳定性，超过了大多数其他基于过渡金属的电催化剂的性能。优异的OER性能可归因于Mo和Fe 的作用，它们调节了CoP的电子性质和结构。结果表明，该表面具有丰富的缺陷和活性位点，Co活性位点比例更高，比表面积更大，界面电荷转移得到改善。X射线光电子能谱（XPS）分析表明，催化剂的高活性源于Mo/Mo和Co/Co氧化还原对的存在，以及其表面活性金属（氧）氢氧化物物种的形成。
