TiO₂/BiVO₄ Nanowire Heterostructure Photoanodes Based on Type II Band Alignment

Abstract

Metal oxides that absorb visible light are attractive for use as photoanodes in photoelectrosynthetic cells. However, their performance is often limited by poor charge carrier transport. We show that this problem can be addressed by using separate materials for light absorption and carrier transport. Here, we report a Ta:TiO2|BiVO4 nanowire photoanode, in which BiVO4 acts as a visible light-absorber and Ta:TiO2 acts as a high surface area electron conductor. Electrochemical and spectroscopic measurements provide experimental evidence for the type II band alignment necessary for favorable electron transfer from BiVO4 to TiO2. The host–guest nanowire architecture presented here allows for simultaneously high light absorption and carrier collection efficiency, with an onset of anodic photocurrent near 0.2 V vs RHE, and a photocurrent density of 2.1 mA/cm2 at 1.23 V vs RHE.

Graphitic-C3N4 hybridized N-doped La2Ti2O7 two-dimensional layered composites as efficient visible-light-driven photocatalyst

“…4b). The result is consistent with a type II band alignment between LTO and g-C 3 N 4 , since the gap between V fb and bottom edge of the conduction band (CB) is assumed to be small (∼0.2 eV) and similar for LTO and g-C 3 N 4 [41]. In type II heterostructure band alignment, the position of CB and valence band (VB) of g-C 3 N 4 is both higher than that of LTO.…”

“…The band bending at the interface of type II heterojunction due to the difference of potential energies between NLTO and g-C 3 N 4 induces a built-in field (Fig. 6b), which promotes the electron-hole pair to facilely migrate to the opposite directions [41]. The large interfacial area of 2D layered g-C 3 N 4 /NLTO composite results in sufficient interface for efficient charge transfer to generate an excellent type II heterojunction.…”

Recent Advances in Bismuth‐Based Nanomaterials for Photoelectrochemical Water Splitting

“…[133] Several studies also report on morphologye ngineering of WO 3 :BiVO 4 to achieve better PEC performance. [138,139] Ar ecent report by Singh et al sheds light on the band engineering of TiO 2 :BiVO 4 ,w hich predicts at ransition from the type Ia lignment to the most efficient type II alignment. [135,136] Thereh ave been severala ttempts to improve the PEC performance of BiVO 4 by its coupling with [130] Reproduced from Ref.…”

Template synthesis of metal tungsten nanowire bundles with high field electron emission performance

“…In recent years, one-dimensional (1D) nanomaterials have attracted great attention in materials science [1][2][3][4][5][6][7][8][9][10] . In particular, 1D metal nanowires with an ordered mesostructure and a high surface area have been intensively investigated because of their unique size-and shape-dependent electronic, magnetic and optical properties [11][12][13][14][15][16][17][18][19] .…”