兰州大学严纯华团队报道了稳定电催化析氧反应的氧硫分布表面包覆工程。相关研究成果于2024年8月26日发表在《德国应用化学》。

阳极氧化环境下不可避免的浸出和腐蚀极大地限制了大多数具有优异原始产氧活性的催化剂的寿命。

该文中，基于菲克定律，研究人员提出了一种表面包覆策略，通过构建具有受控表面厚度的精细包覆型NiO/NiS异质结构，通过界面电子的定向流动和强电子相互作用来减轻镍的溶解并稳定晶格氧的触发。多种原位表征技术表明，该策略可以有效防止不可逆的镍离子浸出，抑制晶格氧参与阳极反应。

结合密度泛函理论计算，研究发现稳定的界面O-Ni-S排列可以促进表面NiO侧的电子积累，削弱其Ni-O共价性。这将抑制镍的过度氧化，同时固定晶格氧，从而使催化剂在不牺牲其活性的情况下具有更高的耐腐蚀性。因此，这种包覆型NiO/NiS异质结构在500小时后表现出优异的性能，超电势低至256 mV。基于菲克定律，该项工作通过精确调节氧硫交换过程证明了表面改性的积极作用，为解决阳极氧化的不稳定性问题铺平了一条创新有效的道路。

附：英文原文

Title: Surface Cladding Engineering via Oxygen Sulfur Distribution for Stable Electrocatalytic Oxygen Evolution Reaction

Author: Li An, Shengjie Zi, Jiamin Zhu, Yue Zhai, Yang Hu, Nan Zhang, Shuhui Li, Luohua Liu, Pinxian Xi, Chun-Hua Yan

Issue&Volume: 2024-08-26

Abstract: Inevitable leaching and corrosion under anodic oxidative environment greatly restrict the lifespan of most catalysts with excellent primitive activity for oxygen production. Here, based on Fick’ s Law, we present a surface cladding strategy to mitigate Ni dissolution and stabilize lattice oxygen triggering by directional flow of interfacial electrons and strong electronic interactions via constructing elaborately cladding-type NiO/NiS heterostructure with controlled surface thickness. Multiple in-situ characterization technologies indicated that this strategy can effectively prevent the irreversible Ni ions leaching and inhibit lattice oxygen from participating in anodic reaction. Combined with density functional theory calculations, we reveal that the stable interfacial O-Ni-S arrangement can facilitate the accumulation of electrons on surficial NiO side and weaken its Ni-O covalency. This would suppress the overoxidation of Ni and simultaneously fixing the lattice oxygen, thus enabling catalysts with boosted corrosion resistance without sacrificing its activity. Consequently, this cladding-type NiO/NiS heterostructure exhibits excellent performance with a low overpotential of 256 mV after 500 h. Based on Fick’s law, this work demonstrates the positive effect of surface modification through precisely adjusting of the oxygen-sulfur exchange process, which has paved an innovative and effective way to solve the instability problem of anodic oxidation.

DOI: 10.1002/anie.202413348

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202413348