Highly efficient photocatalytic overall water splitting in two-dimensional van der Waals MoS2/Hf2CO2 heterostructure

Abstract

Two-dimensional (2D) van der Waals (vdW) heterostructures have attracted much attention due to their unique properties in photocatalysis, electronics, and energy storage. This work comprehensively analyzed the electronic properties and photocatalytic efficiency properties of 2D vdW MoS2/Hf2CO2 heterostructure by first-principles calculations and molecular dynamics simulation. An ideal band gap of 1.44 eV was found for visible light absorption. Meanwhile, a high solar-to-hydrogen efficiency of 17.14% is obtained from the calculated band-edge positions, and a high power conversion efficiency of 13.84% is also confirmed by spectroscopy limited maximum efficiency simulation. We estimate the time scale for electron–hole transfer and recombination times using a combination of non-adiabatic molecular dynamics and time-dependent density functional theory. A suitable e-h recombination time of 1.86 ns and electron (hole) transfer time of 331 (978) fs are obtained in the 2D MoS2/Hf2CO2 heterostructure, which is expected to ensure high photocatalytic efficiency. Therefore, the constructed MoS2/Hf2CO2 heterostructures provide a new example for the prediction of high-performance nano optoelectronic devices.