Visible‐Light‐Driven Photocatalytic Hydrogen Production on Cd0.5Zn0.5S Nanorods with an Apparent Quantum Efficiency Exceeding 80%

Abstract 1D semiconductor nanomaterials have generated a high interest in heterogeneous photocatalysis. However, most 1D photocatalysts still suffer from poor charge separation and severe charge recombination. Herein, a unique approach via surface doping of phosphorus (P) atoms into 1D Cd 0.5 Zn 0.5 S (CZS) nanorods is demonstrated, leading to an imbalanced charge distribution and a localized built‐in electric field, verified by characterizations including photoluminescence and transient absorption spectra. The CZS‐P nanorods exhibit more than two orders of magnitude enhancement in photocatalytic H 2 production activity relative to pristine CZS under visible light. Further construction of spatially separated dual‐cocatalysts (Pt and PdS) on the tip and lateral surface of the CZS‐P nanorods enables a significant improvement in the photocatalytic activity, which results in an apparent quantum efficiency exceeding 89% at 420 nm. Such efficient photocatalytic hydrogen production is attributed to the synergistic effect of tuning the intrinsic built‐in electric field for spatial charge separation and simultaneously accelerating the reduction and oxidation reaction rates utilizing photogenerated charges. The idea of integrating spatial charge separation via morphology tailoring, additional built‐in electric field, and spatial separation of dual‐cocatalysts provides a pathway for rationally designing artificial photocatalysts for solar energy conversion.