In:
Nano-Micro Letters, Springer Science and Business Media LLC, Vol. 14, No. 1 ( 2022-12)
Abstract:
Although bismuth vanadate (BiVO 4 ) has been promising as photoanode material for photoelectrochemical water splitting, its charge recombination issue by short charge diffusion length has led to various studies about heterostructure photoanodes. As a hole blocking layer of BiVO 4 , titanium dioxide (TiO 2 ) has been considered unsuitable because of its relatively positive valence band edge and low electrical conductivity. Herein, a crystal facet engineering of TiO 2 nanostructures is proposed to control band structures for the hole blocking layer of BiVO 4 nanodots. We design two types of TiO 2 nanostructures, which are nanorods (NRs) and nanoflowers (NFs) with different (001) and (110) crystal facets, respectively, and fabricate BiVO 4 /TiO 2 heterostructure photoanodes. The BiVO 4 /TiO 2 NFs showed 4.8 times higher photocurrent density than the BiVO 4 /TiO 2 NRs. Transient decay time analysis and time-resolved photoluminescence reveal the enhancement is attributed to the reduced charge recombination, which is originated from the formation of type II band alignment between BiVO 4 nanodots and TiO 2 NFs. This work provides not only new insights into the interplay between crystal facets and band structures but also important steps for the design of highly efficient photoelectrodes.
Type of Medium:
Online Resource
ISSN:
2311-6706
,
2150-5551
DOI:
10.1007/s40820-022-00795-8
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2022
detail.hit.zdb_id:
2642093-4
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