Anchoring Black Phosphorus Nanoparticles onto ZnS Porous Nanosheets: Efficient Photocatalyst Design and Charge Carrier Dynamics.

Abstract

Black phosphorus nanoparticles (BP NPs) possess great advantages in photocatalysis owing to the rich surface active sites, extremely high carrier mobility, and strong visible-near-infrared light response. However, the complex preparation process, poor stability, and rapid carrier recombination restrict their successful application in photocatalysis. Herein, the above problems are resolved by preparing BP NPs through a facile sonication-assisted hydrothermal method. To further improve the stability and photocatalytic activity, BP NPs are tightly anchored onto ZnS to prepare ZnS-BP porous nanosheets. With the Zn-P coordination bond built between them, higher stability, enhanced carrier transport ability, and excellent hydrogen adsorption and desorption equilibrium of photocatalysts are achieved. An efficient and recyclable photocatalytic hydrogen evolution rate of 1561 μmol h-1 g-1 is obtained under visible-light irradiation, which is superior to that of previously reported BP-based photocatalysts. Besides, the photocatalytic mechanism is investigated based on the theoretical calculations and experimental characterizations. The charge transfer dynamics are studied by surface photovoltage (SPV), ultrafast transient absorption (TA), X-ray absorption spectra (XAS), electrochemical impedance spectroscopy (EIS), and steady-state photoluminescence (PL) spectra. This work set a reference for the design of high-performance BP-related nanomaterials in solar energy storage and conversion.