Carbon-Encapsulated Nickel via Cellulose Acetate Coordination for Efficient Hydrogen Evolution Reactions

Developing efficient and stable electrocatalysts for hydrogen evolution reactions (HERs) is critical for sustainable green hydrogen production. Carbon-coated metal materials are highly promising HER electrocatalysts, offering excellent conductivity, stability, and abundant catalytic sites. However, the synthesis of carbon-coated materials frequently requires expensive precursors or catalysts and may encounter challenges such as poor uniformity in the distribution of the carbon layer. In this work, we employed a straightforward approach that leverages the synergistic chelation effect between cellulose acetate and cotton fabric to coordinate nickel ions, facilitating precursor preparation. The self-supported carbon-coated nickel nanoparticle (CF-C/Ni_x-y) electrocatalyst, characterized by a carbon-encapsulated structure, was successfully synthesized through a one-step pyrolysis process. Through process optimization, the CF-C/Ni₂-900 electrocatalyst pyrolyzed at 900 °C exhibited optimal HER performance in a 1 M KOH electrolyte, achieving an overpotential of 292 mV at a current density of 100 mA cm^-2 and a Tafel slope of 126.4 mV dec^-1. Furthermore, it exhibited sustained high activity for 50 h at a current density of 100 mA cm^-2. This work proposes a rational and feasible strategy for designing self-supported carbon-coated nickel nanoparticle electrocatalysts, offering valuable insights into their potential industrial application in hydrogen production.