Ni and CeO₂ Nanoparticles Anchored on Cicada-Wing-like Nitrogen-Doped Porous Carbon as Bifunctional Catalysts for Water Splitting

Abstract

Slow reaction kinetics, significant overpotential, and high cost remained significant barriers to electrocatalytic water splitting. To address such issues, “cicada-wing-like” nitrogen-doped porous carbon-anchored Ni and CeO2 nanoparticles (CeO2/Ni/NC) were developed and manufactured as a bifunctional catalyst utilizing a modified electrospinning process for overall water splitting. It is worth mentioning that the resulting CeO2/Ni/NC catalyst had excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalytic performance, as well as superior alkaline electrolyte durability. Compared with other nitrogen-doped carbon catalysts, in the OER, it revealed with a lower OER overpotential of 390 mV at 10 mA·cm–2 and a smaller value of the Tafel slope (123 mV·dec–1), while in the HER, it showed an overpotential of 320 mV at 10 mA·cm–2 and a Tafel slope of 150 mV·dec–1. The metallic Ni was the main center of excellent catalytic activity, and the abundant oxygen vacancies and outstanding oxidation/reduction capabilities in CeO2 promoted the overall water splitting. Moreover, the porous nanoarchitecture of matrix material well controlled the size of Ni and CeO2, providing a wealth of active sites, facilitating the electron/ion transfer. This work provided ideas for non-metal-doped carbon-supported catalyst particles, and the catalytic material obtained by the cheap and simple preparation method had an ultrathin microscopic appearance like cicada-wing-like and excellent bifunctional catalytic activity.