Crystal Facet Engineering of -TiO2 Nanostructures for Enhancing Photoelectrochemical Water Splitting with -BiVO4 Nanodots

• 作者: Mi Gyoung Lee Jin Wook Yang Hoonkee Park Cheon Woo Moon Dinsefa M.Andoshe Jongseong Park Chang?Ki Moon Tae Hyung Lee Kyoung Soon Choi Woo Seok Cheon Jang?Joo Kim Ho Won Jang
• 来源期刊: 纳微快报（英文版）
• 年，卷（期）: 2022,（3）
• 页码范围: 201-215
• 页数: 15页
• 语种: 英文

摘要

Although bismuth vanadate -(BiVO4) 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 -BiVO4, titanium dioxide -(TiO2) has been considered unsuitable because of its relatively positive valence band edge and low electrical conductivity. Herein, a crystal facet engineering of -TiO2 nanostructures is proposed to control band structures for the hole blocking layer of -BiVO4 nanodots. We design two types of -TiO2 nanostructures, which are nanorods (NRs) and nanoflowers (NFs) with different (001) and (110) crystal facets, respectively, and fabricate -BiVO4/TiO2 heterostructure photoanodes. The -BiVO4/TiO2 NFs showed 4.8 times higher photocurrent density than the -BiVO4/TiO2 NRs. Transient decay time analysis and time-resolved photoluminescence reveal the enhance?ment is attributed to the reduced charge recombination, which is originated from the formation of type Ⅱ band alignment between -BiVO4 nanodots and -TiO2 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.