Ultrafine Ru nanoparticles confined in 3D nitrogen-doped porous carbon nanosheet networks for alkali-acid Zn-H2 hybrid battery

The rational design of a highly active, stable and Pt-free electrocatalyst for hydrogen evolution reaction (HER) is critical to the development of renewable energy conversion systems but extremely challenging. Herein, a facile top-down strategy is presented to synthesize ultrafine Ru nanoparticles confined in three-dimensional (3D) porous nitrogen-doped carbon nanosheets (Ru/3DNCN). Compared with the state-of-the-art Pt/C catalyst, the Ru/3DNCN exhibits significantly boosted HER activity and stability over a wide pH range, which only requires the overpotential as low as 37 mV, 66 mV, and 17 mV to achieve a current density of 10 mA cm(-2) in 0.5 M H2SO4, 1.0 M PBS, and 1.0 M KOH, respectively. Moreover, an alkali-acid Zn-H-2 battery is assembled by using the Ru/3DNCN as acid cathode and Zn plate as alkaline anode. Such hybrid battery can fulfill simultaneously hydrogen evolution and electricity generation, thanks to harvesting energy from both neutralization and Zn oxidation.

Automated summary

The study presents a facile top-down strategy to synthesize Ru nanoparticles confined in 3D porous nitrogen-doped carbon nanosheets, named Ru/3DNCN, which exhibits significantly boosted HER activity and stability compared to Pt/C catalyst. The Ru/3DNCN only requires low overpotentials to achieve high current densities in various pH environments, and can be used as a catalyst in a hybrid battery for hydrogen evolution and electricity generation.