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

Bi-quantum-dot-modified Bi4V2O11 (BQDs/Bi4V2O11) hollow nanostructures were prepared via a two-step hydrothermal process and used as photocatalysts for CO2 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/Bi4V2O11 composites. The characterization results indicated that the loading of Bi quantum dots (BQDs) on Bi4V2O11 remarkably increases the photoabsorption performance, CO2 absorption capacity, and separation efficiency of photoinduced charge pairs in Bi4V2O11. Most importantly, a significantly enhanced photocatalytic activity toward CO, photoreduction was obtained over the BQDs/Bi4V2O11, composites under simulated sunlight irradiation. A possible enhancement mechanism of CO, photoreduction over BQDs/Bi4V2O11 composites was proposed in which the BQDs as cocatalysts can improve the photocatalytic activity by borrowing the redox conversion between CO2 and BQDs.