Core–Shell Structured Bi/BiOBr Photoelectrodes for Efficient Photoelectrochemical Water Splitting

Abstract

Two-dimensional ternary compounds bismuth oxyhalides (BiO x Br y ) with suitable band gap and high surface bulk ratio have great potentials for photoelectrochemical water splitting. Although intensive efforts were devoted to the design of well-defined nanostructures to optimize the photoreactivity, it remains a great challenge to improve the light absorption capacity and charge carrier transfer of the materials. In this work, we developed a controllable synthesis route to prepare core–shell structured Bi/BiOBr complexes with abundant conduction channels and active edges as photoelectrodes. The structure and morphology of the Bi/BiOBr complexes could be modulated by tuning the thickness of Bi thin film and/or the oxygen gas flow during the annealing process. Photoelectrochemical analyses indicated that the photocurrent density of the Bi/BiOBr electrodes reached up to 0.36 mA cm–2 at −0.4 V versus reversible hydrogen electrode (RHE) in acid environments, which was 1 order large than that based on pure BiOBr thin film electrodes (0.08 mA cm–2). Our study demonstrates that the controllable synthesis of Bi/BiOBr core–shell structures may open a new way for engineering 2D layered ternary compounds materials to develop novel catalyst devices.

Photocatalytic Z‐Scheme Overall Water Splitting: Recent Advances in Theory and Experiments

“…[145] Several other bismuth-based perovskites like Bi 2 WO 6 , BiVO 4 , Bi 4 NbO 8 Cl, and BiOX have been regarded as fabulous photocatalysts with extensive stability and high-water splitting activity. [146] The primary reason behind the performance is the compact hybridization of p orbital of oxygen in junction with 6s orbital of bismuth both in CB and VB. This hybridization between O 2p and Bi 6s orbitals is rendered by raising the VB to a maximum negative value, narrowing the bandgap, and extending the optical absorption to a more extended wavelength region.…”

Morphology-Controlled Electrocatalytic Performance of Two-Dimensional VSe2 Nanoflakes for Hydrogen Evolution Reactions

“…This is also consistent with previous reports for other 2D materials, such as MoS 2 37,38 and BiOBr. 39,40 Other reported TMDC electrocatalysts for the HER with competitive performance in acidic conditions are listed in Table 1. The high conductivity of VSe 2 is a significant contribution to the superior electrochemical abilities in the HER.…”

Turning UV Light-Active BiOF into Visible Light-Active BiOF by Forming a Heterojunction with g-C3N4 and Its Photoelectrochemical Water Splitting Performance in Reverse Osmosis-Rejected Wastewater

“…Hence, the creation of a heterojunction by coupling with different semiconductors can enhance the charge separation and migration as well as the band edge alignment that is beneficial for photoinduced electron–hole pairs, thereby enhancing the PEC efficiency. , Moreover, g-C 3 N 4 -based heterojunction materials improve the PEC activity in solar water splitting . In addition, several heterojunctions such as BiOF/TiO 2 , BiOF/BiOI, BiOBr/BiOF, Ag 2 O/BiOF, BiOBr/Bi 2 O 3 , Bi/BiOBr, MoS 2 /g-C 3 N 4 , TiO 2 /g-C 3 N 4 , and g-C 3 N 4 /BiVO 4 were developed to enhance the photocatalytic properties of BiOF and g-C 3 N 4 . Recently, our group reported the BiOX (X = I, Br, and Cl) heterojunction with g-C 3 N 4 and demonstrated the significant PEC performance in water splitting under AM 1.5 G light irradiation. − In this study, a different wt % (1, 3, 6, and 9 wt %) of g-C 3 N 4 is integrated into BiOF to form a heterojunction interface and the band-gap energy is tuned from the UV to visible region.…”

“…28,29 Moreover, g-C 3 N 4 -based heterojunction materials improve the PEC activity in solar water splitting. 30 In addition, several heterojunctions such as BiOF/TiO 2 , 31 BiOF/BiOI, 32 BiOBr/BiOF, 33 Ag 2 O/BiOF, 34 BiOBr/Bi 2 O 3 , 35 Bi/BiOBr, 36 MoS 2 /g-C 3 N 4 , 37 TiO 2 /g-C 3 N 4 , 38 and g-C 3 N 4 /BiVO 4 39 were developed to enhance the photocatalytic properties of BiOF and g-C 3 N 4 . Recently, our group reported the BiOX (X = I, Br, and Cl) heterojunction with g-C 3 N 4 and demonstrated the significant PEC performance in water splitting under AM 1.5 G light irradiation.…”