Ternary Dumbbell Nanowires for Photocatalytic Hydrogen Production

One-dimensional (1D) semiconductor heterojunctions with asymmetric or symmetric metal cocatalysts are promising systems for high-performance photocatalytic reactions such as solar-to-fuel conversion as the heterostructure junction enables improved charge separation. However, synthesizing such unique heterostructures with well-designed non-noble-metal cocatalysts in an affordable and scalable manner remains a challenging task. Herein, we report the sequential selective growth of ternary dumbbells composed of IrSe2@MoSe2-CdS nanowires (TDNWs), in which clusters of an IrSe2 core coated with a MoSe2 shell are selectively grown on both ends of CdS nanowires (NWs). This special configuration contributes to efficient charge separation. With this unique structure, the TDNWs exhibit a photocatalytic H2 production rate of as high as 137 mmol/g h and an apparent quantum efficiency (AQE) of ∼14.5% within 1 h, which is far superior to those of non-tipped CdS NWs and asymmetrical MoSe2-tipped CdS NWs (ANWs). Our facile synthetic strategy extends spatial anisotropic nanorod growth and enables the construction of advanced multifunctional nano-heterostructures, paving the path for new applications.