Photoanode of LDH catalyst decorated semiconductor heterojunction of BiVO4/CdS to enhance PEC water splitting efficiency

BiVO4 is an ideal photoanode material for solar-driven photoelectrochemical (PEC) water splitting but it easily suffers from the recombination of photogenerated electrons and holes due to its low carrier mobility thus cause low efficiency of PEC water splitting. Herein, the BiVO4/CdS/NiCo-LDH photoanode was prepared by combining methods of metal organic decomposition, chemical and electrodeposition. The photoanode photocurrent density reaches 2.72 mA cm−2 at 1.23 V (vs. RHE), which is 3.6 folds of pure BiVO4 photoanode and onset potential shifts 450 mV toward cathodic. The incident photon-to-electron conversion efficiency (IPCE) value is 2.86 folds of BiVO4, the calculated photon–to–current efficiency (ABPE) is 1.24% at 0.62 V (vs. RHE). The obtained results are higher than that of most BiVO4 based photoanodes published so far. The enhancement benefits from increase of visible light absorption capacity, enhancement of separation efficiency of photoexcited electron-hole and fast transfer of holes accumulated on electrode/electrolyte surface for water oxidation, which has been confirmed by calculating carrier density and carrier transport rate.