Transient absorption measurement is developed to investigate the charge carrier dynamic of different catalyst-modified BiVO₄ and the origin of photocurrent performance enhancement. In-situ IPCE under conditions of transient absorption measurement showed the IPCE enhancement and cathodic shift of onset potential on both Co₉POM and CoPi modified of BiVO₄ compared to bare BiVO₄. The normalized transient absorption kinetics averaged from 500-530 nm exhibited similar slower kinetic decay on both catalysts treated BiVO₄ compared to bare BiVO₄. The power law decay feature of kinetic decay from 10 ns – 500 ns indicates a trap-limited recombination process occurs in all investigated BiVO₄. The slower bulk recombination kinetic decay observed on Co₉POM/BiVO₄ and CoPi/BiVO₄ suggests that both co-catalyst treatments on BiVO₄ enhance the PEC performance by suppressing the bulk recombination process.