Carbon hollow matrix anchored by isolated transition metal atoms serving as a single atom cocatalyst to facilitate the water oxidation kinetics of bismuth vanadate.
J Colloid Interface Sci
; 616: 631-640, 2022 Jun 15.
Article
en En
| MEDLINE
| ID: mdl-35240441
ABSTRACT
Here, nitrogen doped carbon hollow matrix anchored by isolated transition metal atoms (M@NC, M = Fe, Co or Ni) are firstly utilized as new single atom cocatalysts (SACCs) to enhance the PEC performance of Mo, W ions co-doped BiVO4 (Mo, W BVO) through a simple spin-coating method. It is found that Mo, W BVO modified with Fe@NC exhibits higher photocurrent density than the one decorated with Co@NC or Ni@NC due to the relatively low redox potential of Fe3+/Fe2+ (0.77 V vs SHE). During the photoelectrochemical (PEC) process, the Fe2+ ions are easier to accept the photogenerated holes of BVO and be oxidized to Fe3+ ions. Then, Fe3+ ions are reduced to Fe2+ again by accepting the electrons of water, and evolve oxygen simultaneously. Hence, Fe@NC could facilitate the water oxidation kinetics through the redox cycle of Fe ions and promote the charge separation efficiency by capturing the photogenerated holes. Theoretical calculations demonstrate that the deposition of Fe atoms make NC negatively charged, which is conducive to receiving the photogenerated holes. As a result, Mo, W BVO/Fe@NC exhibits higher photocurrent density (3.2 mA/cm2 vs RHE) than other BVO-based samples. This work opens up a new application field of SACCs serving as OER cocatalysts, and may provide a universal strategy to construct the efficient PEC photoelectrodes.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
J Colloid Interface Sci
Año:
2022
Tipo del documento:
Article
País de afiliación:
China