Mo2C-MXene/CdS Heterostructures as Visible-Light Photocatalysts with an Ultrahigh Hydrogen Production Rate

Here, we report a visible-light photocatalyst (Mo 2 C-MXene/CdS) with H 2 production rate higher than that of state-of-the-art catalysts based on noble metals or other MXenes. The photocatalyst was constructed from Mo 2 C MXene, Cd(NO 3 ) 2 ·4H 2 O, and thiourea with ethylenediamine, which has an acanthosphere structure with Mo 2 C two-dimensional (2D) sheets covered by wurtzite CdS nanocrystals. From theoretical calculation, Mo sites in the Mo 2 C-MXene/CdS(110) heterostructure provide an efficient reaction site for the hydrogen evolution reaction (Δ G H* = −0.18 eV). The electronic structures demonstrate that this heterostructure has favorable band gap and band edge position for water splitting. In experimental measurements, the photocatalyst shows a H 2 production rate of 17 964 μmol g –1 h –1 . The H 2 production is ca. 20% higher than the previously reported value of Ti 3 C 2 MXene catalysts and ca. 11% higher than that of noble-metal catalysts. Therefore, Mo 2 C-MXene/CdS heterostructure is a promising catalyst with ultrahigh performance to replace noble-metal catalysts.