Sulfur‐Modified Oxygen Vacancies in Iron–Cobalt Oxide Nanosheets: Enabling Extremely High Activity of the Oxygen Evolution Reaction to Achieve the Industrial Water Splitting Benchmark
Linzhou Zhuang, Yi Jia, Hongli Liu, Zhiheng Li, Mengran Li, Longzhou Zhang, Xin Wang, Dongjiang Yang, Zhonghua Zhu, Xiangdong Yao
Abstract
Abstract The oxygen vacancies of defective iron–cobalt oxide (FeCoO x ‐Vo) nanosheets are modified by the homogeneously distributed sulfur (S) atoms. S atoms can not only effectively stabilize oxygen vacancies (Vo), but also form the Co−S coordination with Co active site in the Vo, which can modulate the electronic structure of the active site, enabling FeCoO x ‐Vo‐S to exhibit much superior OER activity. FeCoO x ‐Vo‐S exhibits a mass activity of 2440.0 A g −1 at 1.5 V vs. RHE in 1.0 m KOH, 25.4 times higher than that of RuO 2 . The Tafel slope is as low as 21.0 mV dec −1 , indicative of its excellent charge transfer rate. When FeCoO x ‐Vo‐S (anode catalyst) is paired with the defective CoP 3 /Ni 2 P (cathode catalyst) for overall water splitting, current densities of as high as 249.0 mA cm −2 and 406.0 mA cm −2 at a cell voltage of 2.0 V and 2.3 V, respectively, can be achieved.