Conformally-coated Nickel-Carbon Nitride on Structured Pyrolytic Carbon Electrodes for Enhanced Hydrogen Evolution

TL;DR

This paper introduces a novel 3D pyrolytic carbon electrode with conformal Ni and CN coatings, significantly enhancing hydrogen evolution reaction performance, corrosion resistance, and durability for sustainable hydrogen production.

Contribution

It presents the first application of CN/Ni/RCD-PyC electrodes for HER, achieving high surface area, improved catalytic activity, and durability in a scalable, cost-effective design.

Findings

Overpotential reduced to 0.6 V in acid and 0.4 V in alkaline media at 10 mA/cm²

Electrode surface area increased over 80 times the geometric area

Maintains performance over 2000 cyclic voltammetry cycles

Abstract

This study presents a three-dimensional electrode for hydrogen evolution reaction (HER), tackling challenges in corrosion resistance, catalytic activity, and durability. The electrode features a rod-connected diamond structure made of pyrolytic carbon (PyC), with sequential Ni and CN conformal coatings, resulting in an increase of its electrochemical active surface area more than 80 times their geometric surface area, marking the first application of CN/Ni/RCD-PyC electrodes for HER. The CN layer enhances corrosion resistance under acidic and alkaline conditions, while synergizing with Ni boosts catalytic activity. We demonstrate that the CN/Ni/RCD-PyC electrode exhibited superior HER activity, achieving lower overpotentials of 0.6 V and 0.4 V for a current density of $\mathrm{10~mA\cdot cm^{-2}}$ in acidic and alkaline media, respectively. The electrode demonstrates excellent durability with performance over 2000 cycles of cyclic voltammetry at high scan rates with no significant decay. Therefore, this electrode offers a scalable, cost-effective solution for sustainable hydrogen production.