Tuning Catalytic Efficiency: Thermodynamic Optimization of Zr-Doped \ce{Ti3C2} and \ce{Ti3CN} MXenes for HER Catalysis

TL;DR

This study uses first-principles calculations to optimize Zr-doped MXenes, demonstrating their potential as cost-effective, high-performance catalysts for hydrogen evolution, advancing sustainable energy solutions.

Contribution

It introduces Zr doping in MXenes as a novel approach to enhance HER catalytic activity through thermodynamic and electronic property optimization.

Findings

Zr doping reduces work function to 3.5-4.5 eV.

Near-zero Gibbs free energy (gh) of 0.16-0.18 eV achieved.

Charge redistribution enhances catalytic performance.

Abstract

Hydrogen production via the Hydrogen Evolution Reaction (HER) is critical for sustainable energy solutions, yet the reliance on expensive platinum (Pt) catalysts limits scalability. Zirconium-doped (\ce{Zr}-doped) MXenes, such as \ce{Ti3C2} and \ce{Ti3CN}, emerge as transformative alternatives, combining abundance, tunable electronic properties, and high catalytic potential. Using first-principles density functional theory (DFT), we show that \ce{Zr} doping at 3\% and 7\% significantly enhances HER activity by reducing the work function to the optimal range of 3.5-4.5~eV and achieving near-zero Gibbs free energy (\dgh) values of 0.18-0.16~eV, conditions ideal for efficient hydrogen adsorption and desorption. Bader charge analysis reveals substantial charge redistribution with enhanced electron accumulation at \ce{Zr} and \ce{N} sites, further driving catalytic performance. This synergy between optimized electronic structure and catalytic properties establishes \ce{Zr}-doped MXenes as cost-effective, high-performance alternatives to noble metals for HER. By combining exceptional catalytic efficiency with scalability, our work positions \ce{Zr}-doped MXenes as a breakthrough for green hydrogen production, offering a robust pathway toward renewable energy technologies and advancing the design of next-generation non-precious metal catalysts.