Efficient photocatalytic overall water-splitting characteristics driven by strain engineering in two-dimensional β-AuTe

Abstract

We discover that applying uniaxial strain from 6% to 12% along the a-direction on the two-dimensional (2D) noble-transition-metal chalcogenide (NTMC) monolayer β-AuTe can promote the emergence of efficient photocatalytic overall water-splitting behavior in acidic environments. Notably, this strain engineering results in a solar-to-hydrogen (STH) efficiency of up to 20.07% for the monolayer β-AuTe. This study provides a more straightforward and cost-effective approach than conventional heterojunction engineering in advanced photocatalytic systems. Under these strain conditions, the monolayer β-AuTe exhibits remarkable stability and flexibility. Its band gap value is well-suited for water-splitting photocatalysis, and the indirect nature of the band gap, combined with highly anisotropic carrier mobilities, significantly enhances photocatalytic activity by reducing the exciton recombination rate. Moreover, within this strain regime, the material demonstrates high absorption coefficients, reaching 10⁴–10⁵ cm⁻¹ in both visible (VIS) and ultraviolet (UV) regions. This study offers theoretical support and practical guidance for applying 2D NTMC materials in advanced photocatalytic systems.