School of Chemical Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China.
Department of Chemical Engineering, University College London, London, WC1E 6 EB, UK.
Adv Sci (Weinh). 2023 May;10(14):e2206952. doi: 10.1002/advs.202206952. Epub 2023 Mar 22.
The development of high-performance, low-cost and rapid-production bifunctional electrocatalysts towards overall water splitting still poses huge challenges. Herein, the authors utilize a facile hydrothermal method to synthesize a novel structure of Co-doped ammonium lanthanum molybdate on Ni foams (Co-ALMO@NF) as self-supported electrocatalysts. Owing to large active surfaces, lattice defect and conductive channel for rapid charge transport, Co-ALMO@NF exhibits good electrocatalytic performances which requires only 349/341 mV to achieve a high current density of 600 mA cm for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Besides, a low cell voltage of 1.52 V is required to reach the current density of 10 mA cm in alkaline medium along with an excellent long-term stability for two-electrode configurations. Density functional theory calculations are performed to reveal the reaction mechanism on Co-ALMO@NF, which shows that the Mo site is the most favorable ones for HER, while the introduction of Co is beneficial to reduce the adsorption intensity on the surface of Co-ALMO@NF, thus accelerating OER process. This work highlighted the importance of the structural design for self-supporting electrocatalysts.
开发高性能、低成本和快速生产的双功能电催化剂以实现整体水分解仍然面临巨大挑战。在此,作者利用简便的水热法在泡沫镍上合成了一种新型的钴掺杂钼酸铵镧(Co-ALMO@NF)作为自支撑电催化剂。由于具有较大的活性表面、晶格缺陷和快速电荷传输的导电通道,Co-ALMO@NF 表现出良好的电催化性能,HER 和 OER 分别仅需 349/341 mV 即可达到 600 mA cm 的高电流密度。此外,在碱性介质中,需要 1.52 V 的低电池电压即可达到 10 mA cm 的电流密度,并且具有出色的两电极配置的长期稳定性。进行了密度泛函理论计算以揭示 Co-ALMO@NF 上的反应机制,结果表明 Mo 位是 HER 最有利的位置,而 Co 的引入有利于降低 Co-ALMO@NF 表面的吸附强度,从而加速 OER 过程。这项工作强调了自支撑电催化剂结构设计的重要性。