Qin Yue, Xu Qingli, Zhao Rong, Wang Qingfa
State Key Laboratory of Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, P. R. China.
Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, P. R. China.
ChemSusChem. 2024 Dec 20;17(24):e202400961. doi: 10.1002/cssc.202400961. Epub 2024 Aug 8.
Developing low-cost and highly efficient electrocatalysts toward oxygen evolution reaction (OER) is of vital significance for electrochemical water splitting. Herein, we fabricate a heterostructure NiS/Ni(OH) electrocatalyst (Ni-S-n) with regenerative oxygen vacancies via electro-deposition on nickel foam (NF) followed by a facile NaBH reduction. The resulting Ni-S-5 catalyst with appropriate amount of oxygen vacancies (O) exhibits extraordinary activity for alkaline OER with overpotential of 142 mV and 248 mV to reach the current density of 10 mA cm and 100 mA cm, respectively. This catalyst also shows remarkable durability with 40 h. After the stability test, the excellent OER performance is well recovered by regenerating the surface oxygen vacancies (O) significantly with additional NaBH reduction. The Ni-S-5 catalyst still displays good activity even after repeating it three times (180 h). The surface oxygen vacancies act as vital active sites for OER. A mechanism of O species transformation and regeneration based on the Ni-S-5 catalyst is proposed, which provides a new direction for exploring ultrastable and efficient OER electrocatalysts with renewable active species.
开发低成本、高效的析氧反应（OER）电催化剂对于电化学水分解具有至关重要的意义。在此，我们通过在泡沫镍（NF）上电沉积，随后进行简便的硼氢化钠还原，制备了一种具有再生氧空位的异质结构NiS/Ni(OH)电催化剂（Ni-S-n）。所得具有适量氧空位（O）的Ni-S-5催化剂对碱性OER表现出非凡的活性，过电位分别为142 mV和248 mV时，电流密度可分别达到10 mA cm和100 mA cm。该催化剂还表现出长达40 h的显著耐久性。稳定性测试后，通过额外的硼氢化钠还原显著再生表面氧空位（O），优异的OER性能得以很好地恢复。即使重复三次（180 h）后，Ni-S-5催化剂仍显示出良好的活性。表面氧空位是OER的重要活性位点。提出了基于Ni-S-5催化剂的O物种转化和再生机制，为探索具有可再生活性物种的超稳定、高效OER电催化剂提供了新方向。
