Photodeposited FeOOH vs electrodeposited Co-Pi to enhance nanoporous BiVO4for photoelectrochemical water splitting

Co-Pi and FeOOH cocatalysts were in - situ deposited on the surface of nanoporous BiVO 4 photoelectrodes. The FeOOH cocatalyst has little effect on the BiVO 4 samples'morphologies, while the electrodeposited Co-Pi cocatalyst seems to affect the surface of BiVO 4 .The impedance intensity modulated photocurrent spectroscopy (IMPS), Mott-Schottky (M-S) techniques characterize BiVO 4 samples photoelectrochemical performance with the deposition of Co-Pi and FeOOH.The Co-Pi/BiVO 4 shows better photoelectrochemical performance than the FeOOH/BiVO 4 , but the FeOOH/BiVO 4 exhibited the better stabilities.The flat band potential and slope of M-S plotof FeOOH/BiVO 4 have little variations compared with BiVO 4 .In contrast, Co-Pi/BiVO 4 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 BiVO 4 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.