Engineering a hierarchical 1D nanorod/3D nanoflower heterojunction via a bimetallic solid solution for enhanced photocatalytic hydrogen evolution

A novel one-dimensional (1D)/three-dimensional (3D) hierarchical heterojunction photocatalyst was rationally designed and synthesized via electrostatic self-assembly, in which 1D Mn0.2Cd0.8S (MCS) nanorods were anchored onto the surface of 3D flower-like MoWS2 (MWS) microspheres. Benefiting from the intimate heterojunction interface, shortened electron transport pathways, and unsaturated sulfur/metal active sites exposed by the 3D flower-like architecture, the optimal composite MM-2 exhibited a superior hydrogen evolution rate (8379.1 μmol·g−1·h−1) under visible light irradiation. In-situ X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations verified the direction of electron transfer from MCS to MWS, confirming the advantage of interfacial electron transfer in bimetallic solid-solution heterojunctions. In addition, transient fluorescence and photoelectrochemical measurements confirmed the existence of an ultrafast electron transfer pathway at the interface between MCS and MWS, which effectively suppresses electron-hole recombination and accelerates charge transfer at the interface. This study provides significant insights into non-noble-metal-based dual solid-solution heterostructures for efficient solar-to-chemical energy conversion, energy substitution, greenhouse gas mitigation, and environmental protection.