Carbon quantum dots coated BiVO4 inverse opals for enhanced photoelectrochemical hydrogen generation.

Carbon quantum dots (CQDs) coated BiVO₄ inverse opal (io-BiVO₄) structure that shows dramatic improvement of photoelectrochemical hydrogen generation has been fabricated using electrodeposition with a template. The io-BiVO₄ maximizes photon trapping through slow light effect, while maintaining adequate surface area for effective redox reactions. CQDs are then incorporated to the io-BiVO₄ to further improve the photoconversion efficiency. Due to the strong visible light absorption property of CQDs and enhanced separation of the photoexcited electrons, the CQDs coated io-BiVO₄ exhibit a maximum photo-to-hydrogen conversion efficiency of 0.35%, which is 6 times higher than that of the pure BiVO₄ thin films. This work is a good example of designing composite photoelectrode by combining quantum dots and photonic crystal. [ABSTRACT FROM AUTHOR]