A simple flame strategy for constructing W‐doped BiVO ₄ photoanodes with enhanced photoelectrochemical water splitting

Abstract

Summary Bismuth vanadate (BiVO4) with narrow band gap has been widely reported in photoelectrochemical (PEC) water splitting. However, the low kinetic of water splitting is still the key for limiting the PEC performance of BiVO4. Herein, a W‐doped BiVO4 (W‐BVO) photoanode has been controllably prepared by a fast flame method within 40 seconds. The preparation condition including calcination time and quantity of W precursor has been systemically investigated, in order to optimize the PEC performance of W‐BVO. X‐ray photoelectron spectroscopy indicates that the introduction of W did not obviously cause the formation of oxygen vacancies, revealing that W has been doped into the crystal structure of BiVO4 by flame method. The electrochemical impedance spectroscopy further confirmed that the W‐BVO possesses a lower charge transfer resistance with fast transfer ability of carriers. Based on the incident photon‐to‐electron conversion efficiency, the acceptable solar to electron conversion efficiency of 5.79% (340 nm, 1.23 V vs RHE) has been achieved in the W‐BVO system. A PEC mechanism has been proposed to demonstrate the promotion of kinetic for PEC water splitting. This work offers a promising alternative route for the design and fabrication of efficient photoanodes in other PEC systems.

Lattice Defects Engineering in W-, Zr-doped BiVO4 by Flame Spray Pyrolysis: Enhancing Photocatalytic O2 Evolution

“…In general, W- or Zr-doping caused rather minor changes in the particle sizes and SSA, see Table 1 . In doped-materials, diffraction peaks from secondary phases such as BiWO 4 at 2θ = 17.2° were detected [ 9 ]. Apart from this, W-doping had no effect on the BiVO 4 peak positions, neither BiVO 4 phase-change, i.e., from monoclinic to tetragonal.…”

“…So far, there is credible evidence that doping of BiVO 4 can be an efficient strategy to improve the photocatalytic performance [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. Highly encouraging results show that appropriate doping of BiVO 4 , i.e., with Mo [ 7 ], W [ 8 , 9 ], P [ 10 ], B [ 11 ] or Ce [ 12 ] can result in significant enhancement of O 2 -evolution. Currently, all reported methods for synthesis of doped BiVO 4 photocatalysts, concern liquid-chemistry methods.…”

Entangled spintronic modulated high‐performance Ce 2 O 3 small polaron surface state‐based water splitting cells

“…14 From recent research, W doped BiVO 4 achieved a fast charge transfer with a low charge transfer resistance, which unfortunately demonstrated only electron conversion efficiency of 5.79% under 1.23 V and light wavelength 340 nm irradiation. 15 On the other hands, seven layers of silicon back-buried junction-based water splitting achieved the conversion efficiency15.62%, 16 which not only gets the potential for furthering raising the performance when the interface resistance can be reduced and the charge mobility can be raised but also over the industrial requirement about 10%. 17 Since the charge transfer and mobility are the issues for raising water splitting efficiency of a devices, [14][15][16] spintronic [18][19][20] demonstrate the promising characteristic for raising the energy conversion efficiency since the spintronic current flows through a material instead of accumulation.…”

“…15 On the other hands, seven layers of silicon back-buried junction-based water splitting achieved the conversion efficiency15.62%, 16 which not only gets the potential for furthering raising the performance when the interface resistance can be reduced and the charge mobility can be raised but also over the industrial requirement about 10%. 17 Since the charge transfer and mobility are the issues for raising water splitting efficiency of a devices, [14][15][16] spintronic [18][19][20] demonstrate the promising characteristic for raising the energy conversion efficiency since the spintronic current flows through a material instead of accumulation. 21 The magnetic moment 22 is currently the easiest mechanism to generate spintronic, which is widely applying in various spintronic devices.…”

“…Among these possible systems, metal‐oxide matrixed photo‐electrochemical water splitting cell gets solar‐to‐hydrogen conversion efficiency around 7.5%, which exceed 10% commercial devices 14 . From recent research, W doped BiVO 4 achieved a fast charge transfer with a low charge transfer resistance, which unfortunately demonstrated only electron conversion efficiency of 5.79% under 1.23 V and light wavelength 340 nm irradiation 15 . On the other hands, seven layers of silicon back‐buried junction‐based water splitting achieved the conversion efficiency15.62%, 16 which not only gets the potential for furthering raising the performance when the interface resistance can be reduced and the charge mobility can be raised but also over the industrial requirement about 10% 17 …”