An Electrochemically Treated BiVO₄ Photoanode for Efficient Photoelectrochemical Water Splitting

Abstract

BiVO 4 films with (040) facet grown vertically on fluorine doped SnO 2 (FTO) glass substrates are prepared by as eed-assisted hydrothermal method. As imple electrochemical treatment process drastically enhances the photocatalytic activity of BiVO 4 ,e xhibiting ar emarkable photocurrent density of 2.5 mA cm À2 at 1.23 Vv s. reversible hydrogen electrode (RHE) under AM 1.5 Gi llumination, which is approximately 10-fold higher than that of the pristine photoanode.Loading cobalt borate (CoBi)ascocatalyst, the photocurrent density of the BiVO 4 photoanode can be further improved to 3.2 mA cm À2 ,d elivering an applied bias photonto-current efficiency (ABPE) of 1.1 %. Systematic studies reveal that crystal facet orientation also synergistically boosts both charge separation and transfer efficiencies,r esulting in remarkably enhanced photocurrent densities.T hese findings provideafacile and effective approach for the development of efficient photoelectrodes for photoelectrochemical water splitting.

Freeing the Polarons to Facilitate Charge Transport in BiVO4 from Oxygen Vacancies with an Oxidative 2D Precursor

“…The intrinsic defects, V O , coulombically drag down the polaron hopping speed and increase the recombination probability, and thus are very unfavorable to the charge separation inside BiVO 4 needed for efficient PEC water splitting. The presently available synthesis for the porous BiVO 4 films is based on a solid‐state reaction, and thus the external dioxygen is difficult to diffuse through the solids to reach the reaction sites . To solve this problem, we developed an internal oxidant route, namely, by using an oxidative precursor, BiOIO 3 , in lieu of BiOI to synthesize nanoporous BiVO 4 films.…”

A Plasma‐Triggered O−S Bond and P−N Junction Near the Surface of a SnS2 Nanosheet Array to Enable Efficient Solar Water Oxidation

“…The Ar plasma treated sample exhibits two semi‐circles, indicating additional interface is formed. The series resistance ( R s ) stands for the impedance between FTO and photoanode, and charge transfer resistance R p1 and R p2 represent the impedance at the interface between SnS 2 /SnS and the photoanode/electrolyte, respectively . The SnS 2 ‐P displays a smaller radius under the light illumination, further confirming the positive role of O−S bond played in the charge transfer.…”

An Efficient Strategy for Boosting Photogenerated Charge Separation by Using Porphyrins as Interfacial Charge Mediators

“…Typically, the calculated τ d values for BV/CoPy/FN‐H and BV/FN‐H are 0.92 and 1.00 ms, respectively, which indicates that the BV/CoPy/FN‐H photoanodes show a higher charge‐transfer rate than that of BV/FN‐H because the “setter” (e.g., CoPy) accelerates the hole transfer from BV to the OEC surface. The τ d value of R‐BV/CoPy/FN‐H is 68 % that of BV/CoPy/FN‐H, thus showing accelerated charge transport kinetics during PEC water oxidation, which may be related to increased carrier density as a result of the introduction of oxygen vacancies …”