Three-Dimensional Nanoporous Heterojunction of Monolayer MoS₂@rGO for Photoenhanced Hydrogen Evolution Reaction

Two-dimensional (2D) semiconductor materials with a large surface area, tunable band gap, and high catalytic activity are emerging as a new class of photoelectrocatalysts. However, the 2D photoelectrocatalysts usually suffer from lower photoelectrochemical efficiency because of the challenges in effectively utilizing the 2D photoelectrocatalysts in three-dimensional electrodes with a reserved surface area and 2D electronic properties. Here, we report novel nanoporous heterojunctions composed of 3D nanoporous reduced graphene oxide (rGO) as visible light absorber and 2D monolayer MoS2 as electron transfer bridge and hydrogen evolution reaction (HER) electrocatalyst for photoelectrochemical hydrogen production. With a designed band alignment between monolayer MoS2 and rGO and a large surface and contact interface, the photoelectrocatalyst shows an outstanding photoenhanced HER activity with a high solar-to-hydrogen conversion efficiency.