The main objective of this project is to understand the charge carrier kinetics in the water oxidation/reduction semiconductor materials. Solar water splitting is a process which converts water into hydrogen and oxygen using solar energy through light driven semiconductor materials. It is considered to be a promising energy solution that can substitute fossil fuels in the future. In this project, in addition to the photoelectrochemistry measurement, the in-situ transient absorption spectroscopy under bias is used to monitor the charge carrier kinetics. Recently, a longer timescale, up to seconds, high sensitivity photolysis setup is also put up to suit the slow kinetics of water oxidation reaction.