Photocatalytic water splitting system using particulate semiconductor materials is a promising strategy for converting solar energy into hydrogen and oxygen. In particular, visible-light-driven ‘Z-schematic’ printable photocatalyst sheets are cost-effective and scalable systems. However, little is known about the fundamental photophysical processes, which are key to explain and promote the photoactivity. Here, we applied the pattern-illumination time-resolved phase microscopy (PI-PM) for the printed photocatalyst sheet, composed of Mo-doped BiVO4 and Rh-doped SrTiO3, indium tin oxide (ITO) as an electron mediator, to investigate photo-generated charge carrier dynamics. Using the PI-PM, we successfully observed for the first time the position- and structure-dependent charge carrier behavior, including visualization of the active/inactive sites in the sheet, under the visible-light irradiation via the time sequence images and the clustering analysis. This combination methodology could not only lead the maximum performance of photocatalyst sheets, but also applicable to other systems involving electron transfer.