The photoelectrochemical (PEC) water splitting performance of BiVO4 is limited by its sluggish surface water oxidation kinetics, which could be addressed by surface modification with oxygen evolution catalysts (OECs) as cocatalysts. Here, an ultrathin layer of cobalt/nickel-based sulfide is successfully deposited on the pyramidal BiVO4 photoanode as a cocatalyst to improve its surface kinetics. An increased photocurrent density and negative shift of onset potential are achieved for this BiVO4/cocatalyst composite, with nearly 99% of surface hole injection yield. The kinetic data based on IMPS show that the presence of a cocatalyst brings about a great decrease in surface charge recombination rate from 150 to 22 s–1 at 0.8 V vs RHE, which reveals that the cobalt/nickel sulfide cocatalyst serves as a passivation layer to suppress recombination at surface states and consequently enhance surface water oxidation kinetics.

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Photoelectrochemical water splitting (PEC) is seen as a promising approach to address the energy and environmental crises. Here, we adopted a simple two-step method to synthesize bare Sb2S3 film, and then employed a Bi element doping strategy to improve the PEC performance of obtained bare Sb2S3. The obtained Bi-Sb2S3 exhibited an increased photocurrent density, 2.8 mA/cm2 at 1.23 VRHE and a negative shift of onset potential compared to bare Sb2S3. The enhancement in PEC performance of Bi-Sb2S3 could be attributed to the expanded light absorption range, increased electron carrier concentration, and improved charge transfer ability.

Photoelectrochemical water oxidation for hydrogen generation via utilizing sunlight is considered a very promising pathway for generating sustainable energy in an environmental manner. Here, a composite photoanode, consisting of nanopyramidal BiVO 4 arrays and one layered double hydroxide (NiMn-LDH) was designed and fabricated via a facile route. The obtained BiVO 4 /NiMn-LDH composite photoelectrode presented a significant enhancement in the photoelectrochemical (PEC) current density, conversion efficiency and stability for solar water oxidation. With 2D NiMn-LDH decoration, an obvious cathodic shift of ∼480 mV in the onset potential can be observed, and more than two times enhancement in photocurrent performance is achieved. The improvement in photoelectrochemical activity for BiVO 4 /NiMn-LDH composite photoanode can be attributed to the enhanced water-oxidation kinetics leading to the efficient separation, transfer and collection of charge carriers at the photoanode/electrolyte interface. The result demonstrates NiMn-LDH represents one of the active oxygen evolution catalysts (OECs) to improve the PEC activity of metal oxide photoanode.