Peng Qimin, Zhuang Xiaoling, Wei Longgui, Shi Luyan, Isimjan Tayirjan Taylor, Hou Ruobing, Yang Xiulin
Guangxi Key Laboratory of Low Carbon Energy Materials, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, P. R. China.
Saudi Arabia Basic Industries Corporation (SABIC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
ChemSusChem. 2022 Aug 19;15(16):e202200827. doi: 10.1002/cssc.202200827. Epub 2022 Jul 6.
Developing cost-effective, highly active, and robust electrocatalysts for oxygen evolution reaction (OER) at high current density is a critical challenge in water electrolysis since the sluggish kinetics of the OER significantly impedes the energy conversion efficiency of overall water splitting. Here, a 1D nanothorn-like Nb-CoSe /CC (CC=carbon cloth) structure was developed as an efficient OER catalyst. The optimized Nb-CoSe /CC catalyst exhibited remarkable OER performance with the low overpotentials of 220 mV at 10 mA cm and 297 mV 200 mA cm and a small Tafel slope (54.1 mV dec ) in 1.0 m KOH electrolyte. More importantly, the Nb-CoSe /CC electrode displayed superior stability after 60 h of continuous operation. In addition, cell voltages of 1.52 and 1.93 V were required to achieve 10 and 500 mA cm for the electrolyzer made of Nb-CoSe /CC (anode) and the Pt/C (cathode). Density functional theory (DFT) calculations combined with experimental results revealed that incorporating niobium into the CoSe could optimize the adsorption free energy of the reaction intermediates and enhance the conductivity to improve the catalytic activity further. Additionally, the super-hydrophilicity of Nb-CoSe /CC resulting from the surface defects increased the surface wettability and facilitated reaction kinetics. These results indicate that Nb-CoSe /CC intrinsically enhances OER performance and possesses potential practical water electrolysis applications.
开发用于在高电流密度下进行析氧反应（OER）的具有成本效益、高活性且稳健的电催化剂是水电解中的一项关键挑战，因为OER缓慢的动力学显著阻碍了整体水分解的能量转换效率。在此，一种一维纳米刺状的Nb-CoSe₂/CC（CC = 碳布）结构被开发为一种高效的OER催化剂。优化后的Nb-CoSe₂/CC催化剂表现出卓越的OER性能，在1.0 M KOH电解液中，在10 mA cm⁻²时过电位低至220 mV，在200 mA cm⁻²时为297 mV，且塔菲尔斜率较小（54.1 mV dec⁻¹）。更重要的是，Nb-CoSe₂/CC电极在连续运行60小时后显示出优异的稳定性。此外，由Nb-CoSe₂/CC（阳极）和Pt/C（阴极）制成的电解槽在达到10和500 mA cm⁻²时所需的电池电压分别为1.52和1.93 V。密度泛函理论（DFT）计算与实验结果相结合表明，将铌掺入CoSe₂中可以优化反应中间体的吸附自由能并提高电导率，从而进一步提高催化活性。此外，由表面缺陷导致的Nb-CoSe₂/CC的超亲水性增加了表面润湿性并促进了反应动力学。这些结果表明，Nb-CoSe₂/CC本质上提高了OER性能，并具有潜在的实际水电解应用前景。
