# Nitrogen plasma engineered MoS2 for catalyzing hydrogen evolution reaction

## TL;DR

This paper introduces a nitrogen plasma treatment to enhance the hydrogen evolution reaction performance of molybdenum disulfide by activating its basal plane.

## Contribution

A remote nitrogen plasma method is proposed to dope and activate monolayer MoS2 for improved electrocatalytic activity.

## Key findings

- N-doped monolayer MoS2 achieves a HER overpotential of 348 mV at 10 mA cm−2.
- Nitrogen incorporation increases active-site density and induces charge redistribution.
- Theoretical calculations reveal a reduced band gap and optimized ΔGH of 0.10 eV.

## Abstract

Monolayer molybdenum disulfide (MoS2) possesses exceptional electrical characteristics and a substantial specific surface area, rendering it an optimal material for electrocatalysis. However, its inert basal planes account for a relatively large proportion, and the limited exposure of active edge sites restricts its further utilization and development. Here, we report a remote nitrogen (N)-plasma treatment that incorporates substituted N into monolayer MoS2 (ML-MoS2) and activates its basal plane for the hydrogen evolution reaction (HER). The optimized N-doped ML-MoS2 delivers an overpotential of 348 mV at 10 mA cm−2 and a Tafel slope of 94 mV·dec−1. Experimental and theoretical results show that nitrogen incorporation induces lattice defects and charge redistribution and increases active-site density, thereby enhancing HER activity. This plasma-based, controllable surface activation strategy provides a scalable route to tune the catalytic performance of two-dimensional transition-metal dichalcogenides.

•Remote N-plasma treatment enables controlled doping in monolayer MoS2•N-doping activates the inert basal plane via charge redistribution•Optimized MoS2 exhibits a low HER overpotential of 348 mV•Calculations show reduced band gap and optimized ΔGH of 0.10 eV

Remote N-plasma treatment enables controlled doping in monolayer MoS2

N-doping activates the inert basal plane via charge redistribution

Optimized MoS2 exhibits a low HER overpotential of 348 mV

Calculations show reduced band gap and optimized ΔGH of 0.10 eV

Electrochemistry; Applied sciences