Boosting Photoelectrochemical Water Oxidation with Cobalt Phosphide Nanosheets on Porous BiVO₄

Abstract

Modification of the semiconductor surface by cobalt-rich catalysts is an effective strategy to improve the photoelectrochemical (PEC) water oxidation kinetics and migration of photogenerated electron and hole. In this study, cobalt phosphide (CoP) nanosheet was integrated on the nanoporous bismuth vanadate (BiVO4) electrode by using the hydrothermal method. The introduction of CoP significantly improved the PEC performance of the photoanode, with a photocurrent up to 4.0 mA cm–2 at 1.23 V (versus RHE) under simulated 100 mW cm–2 irradiation, a 3-fold enhancement over that obtained by the bare BiVO4. The BiVO4+CoP photoanode exhibited an impressive early onset of water oxidation, with a more than 220 mV cathodic shift of the onset potential, superior to the typical Co3O4 and Co–Pi cocatalysts-modified BiVO4 photoanode. Systematic studies show that the improvement in PEC performance by CoP is mainly due to the restraint of surface charge recombination and increase in photovoltage.

Strategies for Semiconductor/Electrocatalyst Coupling toward Solar‐Driven Water Splitting

“…Besides metal sulfides, oxides, and LDHs, some emerging or complex catalysts were also reported to be able to couple to semiconductor photoelectrodes via hydrothermal/solvothermal treatment. For example, Xia et al recently reported hydrothermal deposition of CoP NSs on porous BiVO 4 , which resulted in a cathodic shift in onset potential by more than 220 mV and an improved photocurrent density of 4.0 mA cm −2 at 1.23 V RHE , superior to that of porous BiVO 4 modified by Co 3 O 4 and Co‐Pi catalysts. Furthermore, the authors compared the PEC performance of the BiVO 4 modified by hydrothermally loaded CoP NSs to that of the BiVO 4 modified by drop‐cast CoP NSs, and found that the former markedly outperformed the latter.…”

Preparation of Helical BiVO4/Ag/C3N4 for Selective Oxidation of C–H Bond under Visible Light Irradiation

“…The two peaks at 368.2 and 374.2 eV are ascribed to the Ag 3d signals of metallic Ag 0 species (Figure S6b). , As shown in Figure S6c, the Bi 4f 7/2 and Bi 4f 5/2 peaks are at 164.4 and 159.1 eV binding energies, respectively, ascribable to Bi 3+ . The V 2p spectrum shows a peak at approximately 516.8 eV, which can be attributed to V 5+ .…”

Oxygen Evolution Catalysts at Transition Metal Oxide Photoanodes: Their Differing Roles for Solar Water Splitting

“…manage to find a superior performance of the unique core‐shell structure of CoP/CoO x on BiVO 4 in a borax buffer solution when compared with CoPi and Co 3 O 4 . [ 141 ] The better photovoltage of BiVO 4 /CoP is responsible for this excellent photocurrent rather than a better OER kinetics. In these types of core–shell OECs, the metal oxide/oxyhydroxide is the actual catalytic site, while the metal phosphide core serves as a conducting pathway for holes to be transported to the shell.…”