Qin Yan, Wang Caizheng, Hou Xinran, Zhang Huijie, Tan Zhaoyang, Wang Xiaobin, Li Jingde, Wu Feichao
Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China.
Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China.
J Colloid Interface Sci. 2024 Nov 15;674:1092-1102. doi: 10.1016/j.jcis.2024.07.104. Epub 2024 Jul 14.
It is critical and challenging to develop highly active and low cost bifunctional electrocatalysts for the hydrogen/oxygen evolution reaction (HER/OER) in water electrolysis. Herein, we propose cerium-vanadium-based hollow nanopillar arrays supported on nickel foam (CeV-HNA/NF) as bifunctional HER/OER electrocatalysts, which are prepared by etching the V metal-organic framework with Ce salt and then pyrolyzing. Etching results in multidimensional optimizations of electrocatalysts, covering substantial oxygen vacancies, optimized electronic configurations, and an open-type structure of hollow nanopillar arrays, which contribute to accelerating the charge transfer rate, regulating the adsorption energy of H/O-containing reaction intermediates, and fully exposing the active sites. The reconstruction of the electrocatalyst is also accelerated by Ce doping, which results in highly active hydroxy vanadium oxide interfaces. Therefore, extremely low overpotentials of 170 and 240 mV under a current density of 100 mA cm are achieved for the HER and OER under alkaline conditions, respectively, with long-term stability for 300 h. An electrolysis cell with CeV-HNA/NF as both the cathode and anode delivers a small voltage of 1.53 V to achieve water electrolysis under 10 mA cm, accompanied by superior durability for 150 h. This design provides an innovative way to develop advanced bifunctional electrocatalysts for overall water electrolysis.
开发用于水电解中析氢/析氧反应（HER/OER）的高活性、低成本双功能电催化剂至关重要且具有挑战性。在此，我们提出了负载在泡沫镍上的铈钒基中空纳米柱阵列（CeV-HNA/NF）作为双功能HER/OER电催化剂，它是通过用铈盐蚀刻V金属有机框架然后热解制备的。蚀刻导致电催化剂的多维度优化，包括大量氧空位、优化的电子构型以及中空纳米柱阵列的开放型结构，这有助于加快电荷转移速率、调节含H/O反应中间体的吸附能并充分暴露活性位点。Ce掺杂还加速了电催化剂的重构，从而产生高活性的羟基钒氧化物界面。因此，在碱性条件下，HER和OER在100 mA cm的电流密度下分别实现了170和240 mV的极低过电位，具有300小时的长期稳定性。以CeV-HNA/NF作为阴极和阳极的电解槽在10 mA cm下实现水电解时提供1.53 V的小电压，并具有150小时的优异耐久性。这种设计为开发用于全水电解的先进双功能电催化剂提供了一种创新方法。
