서강대학교

초록/요약 도움말

Monoclinic BiVO4 monolayers with exposed (040) facet were fabricated successfully by finger rubbing and spin coating methods to use as a seed layer of BiVO4 nanocrystals for the secondary growth. The fabricated monolayer of BiVO4 nanocrystal monolayers were allowed to do the secondary growth by hydrothermal reaction with a seed layer coated on the FTO glass. The effects of the pH, addition of TiCl3, reaction time and different concentration were comparatively studied to get the most efficient synthesis of BiVO4 nanocrystal films exposed with (040) facet dominantly. The addition of TiCl3 was done as a selective (040) facet grow-ing control agent during the secondary growth reaction by suppressing the growth of other facets. The characterization on the structure of the films was carried out by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The photoactivity of the films was characterized with current-voltage curves. The dominant exposure of (040) facet of BiVO4 is leading to higher photoactivity to give higher photocurrent value and the films also can be used by photoanode to produce O2 gas evolution by water splitting. For the theoretical calculation of surface energy of BiVO4 crystal facets to know the highest photoactive facet of BiVO4 nanocrystals, the optimization of unit cell of monoclinic BiVO4 was performed by using the Vienna ab initio simulation package (VASP). The theoretical prediction was comparatively studied with the experimental results of photo-current values and O2 evolution data with IPCE and GC to get the optimized preparation conditions for the highest efficiency of water splitting reaction. Surface charge value was de-termined with zeta potentiometer.