Co-Pi and FeOOH cocatalysts were in-situ deposited on the surface of nanoporous BiVO4 photoelectrodes.The FeOOH cocatalyst has little effect on the BiVO4 samples' morphologies,while the electrodeposited CoPi cocatalyst seems to affect the surface of BiVO4.The impedance intensity modulated photocurrent spectroscopy (IMPS),Mott-Schottky (M-S) techniques characterize BiVO4 samples photoelectrochemical performance with the deposition of Co-Pi and FeOOH.The Co-Pi/BiVO4 shows better photoelectrochemical performance than the FeOOH/BiVO4,but the FeOOH/BiVO4 exhibited the better stabilities.The fiat band potential and slope of M-S plotof FeOOH/BiVO4 have little variations compared with BiVO4.In contrast,Co-Pi/BiVO4 exhibited the down shifted flat band potential,which is beneficial for the photoelectrochemical water oxidation.The electron transfer measurements revealed that the deposition of FeOOH and Co-Pi onto BiVO4 significantly enhanced the photoelectrochemical performance via reducing the interface resistance and promoting the electron transport.Furthermore,Co-Pi cocatalysts can further pin the transport-limiting traps and significantly facilitate the electron transport.