Bi-Quantum-Dot-Decorated Bi4V2O11 Hollow Nanocakes: Synthesis, Characterization, and Application as Photocatalysts for CO2 Reduction

Bi-quantum-dot-modified Bi 4 V 2 O 11 (BQDs/Bi 4 V 2 O 11 ) hollow nanostructures were prepared via a two-step hydrothermal process and used as photocatalysts for CO 2 photoreduction under simulated sunlight irradiation. Characterization techniques including X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, ultraviolet–visible diffuse reflection spectroscopy, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, N 2 adsorption–desorption, and photoelectrochemical measurements were utilized to investigate the crystal structure, morphology, optical property, and photoelectrochemical property of as-prepared BQDs/Bi 4 V 2 O 11 composites. The characterization results indicated that the loading of Bi quantum dots (BQDs) on Bi 4 V 2 O 11 remarkably increases the photoabsorption performance, CO 2 absorption capacity, and separation efficiency of photoinduced charge pairs in Bi 4 V 2 O 11 . Most importantly, a significantly enhanced photocatalytic activity toward CO 2 photoreduction was obtained over the BQDs/Bi 4 V 2 O 11 composites under simulated sunlight irradiation. A possible enhancement mechanism of CO 2 photoreduction over BQDs/Bi 4 V 2 O 11 composites was proposed in which the BQDs as cocatalysts can improve the photocatalytic activity by borrowing the redox conversion between CO 2 and BQDs.