Graphene composites with Ru-RuO2 heterostructures: Highly efficient Mott-Schottky-type electrocatalysts for pH-universal water splitting and flexible zinc-air batteries

作者：Wang, Nan; Ning, Shunlian; Yu, Xiaolong; Chen, Di; Li, Zilong; Xu, Jinchang; Meng, Hui^*; Zhao, Dengke; Li, Ligui^*; Liu, Qiming; Lu, Bingzhang; Chen, Shaowei^*

来源：Applied Catalysis B: Environmental , 2022, 302: 120838.

DOI：10.1016/j.apcatb.2021.120838

• Mott-Schottky junction
• Graphene nanocomposite
• Ru-RuO2 heterostructure
• Water splitting
• Metal-air battery

Development of high-efficiency electrocatalysts for pH-universal overall water splitting is a critical step towards a sustainable hydrogen economy. Herein, graphene nanocomposites with Ru-RuO2 Mott-Schottky heterojunctions (Ru-RuO2@NPC) are prepared pyrolytically and exhibit a remarkable electrocatalytic activity at pH = 0-14 towards both oxygen/hydrogen evolution reactions and overall water splitting, as compared to commercial RuO2 and Pt/C. Ru-RuO2@NPC can also be used as an effective air cathode catalyst for flexible, rechargeable zinc-air batteries. Density functional theory calculations show that the formation of Ru-RuO2 heterojunctions moderately enhances the surface charge density of metallic Ru and brings the d states closer to Fermi level, as compared to that of RuO2 alone, leading to improved intrinsic electrocatalytic activity towards these important reactions. These results demonstrate the significance of Mott-Schottky heterojunctions in the development of high-efficiency electrocatalysts for various new energy technologies.

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  茂名学院