Ibrahim Kassa Belay, Shifa Tofik Ahmed, Bordin Matteo, Moretti Elisa, Wu Heng-Liang, Vomiero Alberto
Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Mestre, 30170, Italy.
Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan.
Small Methods. 2023 Oct;7(10):e2300348. doi: 10.1002/smtd.202300348. Epub 2023 Jun 23.
Basic insight into the structural evolution of electrocatalysts under operating conditions is of substantial importance for designing water oxidation catalysts. The first-row transition metal-based catalysts present state-of-the-art oxygen evolution reaction (OER) performance under alkaline conditions. Apparently, confinement has become an exciting strategy to boost the performance of these catalysts. The van der Waals (vdW) gaps of transition metal dichalcogenides are acknowledged to serve as a suitable platform to confine the first-row transition metal catalysts. This study focuses on confining Ni(OH) nanoparticle in the vdW gaps of 2D exfoliated SnS (Ex-SnS ) to accelerate water oxidation and to guarantee long term durability in alkaline solutions. The trends in oxidation states of Ni are probed during OER catalysis. The in situ studies confirm that the confined system produces a favorable environment for accelerated oxygen gas evolution, whereas the un-confined system proceeds with a relatively slower kinetics. The outstanding OER activity and excellent stability, with an overpotential of 300 mV at 100 mA cm and Tafel slope as low as 93 mV dec results from the confinement effect. This study sheds light on the OER mechanism of confined catalysis and opens up a way to develop efficient and low-cost electrocatalysts.
深入了解电催化剂在工作条件下的结构演变对于设计析氧催化剂至关重要。第一排过渡金属基催化剂在碱性条件下展现出了最先进的析氧反应（OER）性能。显然，限域已成为提高这些催化剂性能的一种令人兴奋的策略。过渡金属二硫属化物的范德华（vdW）间隙被认为是限域第一排过渡金属催化剂的合适平台。本研究聚焦于将Ni(OH)纳米颗粒限域在二维剥离的SnS（Ex-SnS）的vdW间隙中，以加速析氧并确保在碱性溶液中的长期耐久性。在OER催化过程中探究了Ni的氧化态变化趋势。原位研究证实，限域体系为加速析氧产生了有利环境，而非限域体系的反应动力学相对较慢。在100 mA cm时过电位为300 mV且塔菲尔斜率低至93 mV dec的出色OER活性和优异稳定性源于限域效应。本研究阐明了限域催化的OER机理，并为开发高效低成本的电催化剂开辟了一条道路。
