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

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 Cd0.5Zn0.5S (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.