# Engineering Doping and Vacancy in a C3N4 Electrocatalyst with Ni4Mo Cocatalyst for Efficient Alkaline Hydrogen Evolution

## TL;DR

This paper introduces a phosphorus-doped carbon nitride electrocatalyst with a Ni4Mo cocatalyst that efficiently produces hydrogen in alkaline conditions.

## Contribution

The novel use of phosphorus doping and nitrogen vacancies in C3N4 with a Ni4Mo cocatalyst achieves high HER performance without noble metals.

## Key findings

- Phosphorus doping improves electronic conductivity and creates active sites for hydrogen evolution.
- The catalyst achieves a low overpotential of 93 mV at −10 mA·cm–2 and a Tafel slope of 88 mV·dec–1.
- Nitrogen vacancies and Ni4Mo cocatalyst synergistically enhance catalytic activity.

## Abstract

To meet the growing
demand for sustainable hydrogen production,
robust and cost-effective electrocatalysts are essential, especially
under alkaline conditions. Herein, we report a phosphorus-doped carbon
nitride (P–C3N4) electrocatalyst exhibiting
remarkable hydrogen evolution reaction (HER) performance in an alkaline
electrolyte. Phosphorus doping was found to promote electronic conductivity
and create Lewis acidic active sites, facilitating water dissociation
and hydrogen adsorption. Electrochemical measurements revealed a significant
reduction in overpotential and Tafel slope upon optimal P-doping (2.0
at%). Further introduction of nitrogen vacancies (NV) and coloading
with Ni4Mo bimetallic alloy synergistically enhanced the
catalytic activity, delivering an overpotential (η10) as low as 93 mV at −10 mA·cm–2 and
a Tafel slope of 88 mV·dec–1, without reliance
on noble metals. These results underscore the promise of defect-engineered
C3N4 systems as viable catalysts for green hydrogen
generation.