Synergy of charge migration direction-manipulated Z-scheme heterojunction of BiVO4 quantum dots/perylenetetracarboxylic acid and nanosized Au modification for artificial H2O2 photosynthesis

Abstract

Herein, perylenetetracarboxylic acid (PTA) nanosheets with anisotropic charge migration driven by the formed internal electric fields are synthesized through a facile hydrolysis-reassembly process. Strategically, a Z-scheme heterojunction with free-flowing interfacial charge transfer and spatially separated redox centers is constructed based on the distinct photogenerated electrons and holes accumulation regions of PTA nanosheets by in-situ introducing BiVO₄ quantum dots (BQD) and nanosized Au. The optimized BQD/PTA-Au exhibits a ca. 6.4-fold and 4.8-fold enhancement in H₂O₂ production rate and apparent quantum yield at 405 nm compared with pristine PTA, respectively. The exceptional activities are attributed to the cascade Z-scheme charge transfer followed the matched charge migration orientation, as well as the Au active sites for accelerating 2e^– oxygen reduction pathway induced by superoxide radicals, as unraveled by electron paramagnetic resonance, in-situ irradiated X-ray photoelectron spectroscopy and in-situ diffuse reflectance infrared Fourier transformation spectroscopy. This work provides a strategy to design an efficient Z-scheme system towards solar-driven H₂O₂ production.