Ni<sub>3</sub>V<sub>2</sub>O<sub>8</sub> Nanospheres for Sustained and Efficient Enhancement of Electrocatalytic H<sub>2</sub>O<sub>2</sub> Production in pH-Universal Solutions
Zhikang Bao, Wenjuan Fang, Jiayuan Li, Yizhen Shao, Yuanan Li, Shijie Zhang, Xiaoge Peng, Chenghang Jiang, Xing Zhong, Jianguo Wang
Abstract
Electrosynthesis of hydrogen peroxide (H 2 O 2 ) is an energy-efficient and environmentally friendly approach with the potential for on-site generation and application but is severely constrained by the lack of efficient and stable catalysts to activate the two-electron oxygen reduction reaction with high selectivity and generate H 2 O 2 in high yield. Herein, we report a nickel vanadate catalyst (Ni 3 V 2 O 8 -NS) featuring high selectivity, activity, and stability. The Ni 3 V 2 O 8 -NS catalyst exhibited high H 2 O 2 selectivity across pH-universal electrolytes (acidic 92.28%, neutral 92.76%, and basic 92.36%), giving a record high yield of 44,010 mmol h –1 g catalyst –1 (neutral) and 38,043 mmol h –1 g catalyst –1 (weakly acidic) in a customized flow cell and displayed good stability during a 10-cycles test (each cycle lasting 10 h) and at high concentration (10 wt %). Based on in situ spectroscopic and density functional theory calculations, the effect of Ni–V on the selectivity of H 2 O 2 is revealed, the introduction of V changing the coordination environment of surface Ni and providing a more suitable adsorption energy of the intermediate *OOH, resulting in its high catalytic activity. Furthermore, the concept of on-site application and production of H 2 O 2 was demonstrated through in situ oxidative degradation of dyes and antibiotics. This work has designed a metal catalyst with promising electrocatalytic performance, shedding light on the potential practicality of on-site generation and application of H 2 O 2 .