Densely populated tiny RuO2 crystallites supported by hierarchically porous carbon for full acidic water splitting

• Published in: Materials horizons Vol. 10; no. 10; pp. 4589 - 4596
• Main Authors: Yu, Bo, Jin-Hang, Liu, Guo, Shuaibiao, Huang, Guanlin, Zhang, Shengjia, Chen, Shuangqiang, Li, Xiaopeng, Wang, Yong, Li-Ping, Lv
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 02.10.2023
• Subjects: Acid resistance; Acidic water; Carbon; Corrosion resistance; Crystallites; Electrocatalysts; Heterostructures; Hydrogen evolution reactions; Mass transfer; Molten salts; Nanoparticles; Oxygen evolution reactions; Ruthenium; Ruthenium oxide; Sulfuric acid; Water splitting
• ISSN: 2051-6347; 2051-6355; 2051-6355
• DOI: 10.1039/d3mh00587a

The exploitation of highly active bifunctional electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in acidic media has been a subject receiving immense interest. However, the existing catalysts usually suffer from low catalytic efficiency and poor corrosion resistance under acidic conditions. Herein, we report a facile molten salt method to fabricate ruthenium dioxide nanoparticles supported by hierarchically porous carbon (RuO2/PC) as a bifunctional electrocatalyst for full water splitting under strong acidic conditions. The formation of a densely populated nanocrystalline RuO2/carbon heterostructure helps expose catalytic sites, accelerates the mass transfer rate, and further enhances the acid resistance of RuO2 nanoparticles. The as-synthesized RuO2/PC consequently exhibits superior catalytic performance for the OER with an overpotential of 181 mV upon 10 mA cm−2 compared to that of the commercial RuO2 (343 mV) and a comparable performance to Pt/C for the HER (47.5 mV upon 10 mA cm−2) in 0.5 M H2SO4. The RuO2/PC shows promising stability with little degradation over ∼24 h. Impressively, the water electrolyzer based on RuO2/PC shows an overpotential of 326 mV at 10 mA cm−2, much lower than that of the electrolyzer based on the combination of Pt/C and RuO2 (400 mV), indicating its great potential towards practical application.