Zhao Ling, Tao Zetian, You Maosheng, Xiao Huangwei, Wang Sijiao, Ma Wenjia, Huang Yonglong, He Beibei, Chen Qi
School of Marine Science and Engineering, Hainan University, Haikou, 570228, P. R China.
Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, P. R. China.
Adv Sci (Weinh). 2024 Jun;11(24):e2309750. doi: 10.1002/advs.202309750. Epub 2024 Apr 2.
The pursuit of efficient and durable bifunctional electrocatalysts for overall water splitting in acidic media is highly desirable, albeit challenging. SrIrO based perovskites are electrochemically active for oxygen evolution reaction (OER), however, their inert activities toward hydrogen evolution reaction (HER) severely restrict the practical implementation in overall water splitting. Herein, an Ir@SrIrO heterojunction is newly developed by a partial exsolution approach, ensuring strong metal-support interaction for OER and HER. Notably, the Ir@SrIrO-175 electrocatalyst, prepared by annealing SrIrO in 5% H atmosphere at 175 °C, delivers ultralow overpotentials of 229 mV at 10 mA cm for OER and 28 mV at 10 mA cm for HER, surpassing most recently reported bifunctional electrocatalysts. Moreover, the water electrolyzer using the Ir@SrIrO-175 bifunctional electrocatalyst demonstrates the potential application prospect with high electrochemical performance and excellent durability in acidic environment. Theoretical calculations unveil that constructing Ir@SrIrO heterojunction regulates interfacial electronic redistribution, ultimately enabling low energy barriers for both OER and HER.
尽管具有挑战性，但在酸性介质中寻找高效耐用的双功能电催化剂用于全水解仍是非常必要的。基于SrIrO的钙钛矿对析氧反应（OER）具有电化学活性，然而，它们对析氢反应（HER）的惰性严重限制了其在全水解中的实际应用。在此，通过部分析出来新开发了一种Ir@SrIrO异质结，确保了对OER和HER的强金属-载体相互作用。值得注意的是，通过在5%H气氛中于175°C对SrIrO进行退火制备的Ir@SrIrO-175电催化剂，在10 mA cm时对OER的过电位超低，为229 mV，对HER的过电位为28 mV，超过了最近报道的双功能电催化剂。此外，使用Ir@SrIrO-175双功能电催化剂的水电解槽在酸性环境中显示出具有高电化学性能和优异耐久性的潜在应用前景。理论计算表明，构建Ir@SrIrO异质结可调节界面电子重新分布，最终实现OER和HER的低能垒。
