Production of photoexcited charge carriers serves as the foundation for the basic mechanism of photocatalysis water splitting. Three key steps are typically involved in the photocatalytic water splitting reaction on semiconductor particles: (1) absorption of photons with energies above that of semiconductor bandgap, (2) separation of the generated electrons and holes, and (3) migration of these charges to the interface of the semiconductor particles. Surface chemical reactions between these charge carriers available on the photocatalyst interface result in the production of H2 and O2, respectively. Without taking part in any chemical reactions, the recombination of electrons and holes is another possibility that might happen in a very short period.

Researchers in the institute are experimenting with photo and photo electrocatalytic dissociation of water by visible light using up-conversion material incorporated semiconductors. Semiconductors with up-conversion (UC) effects have attracted considerable attention due to their ability to upconvert visible or near-infrared light to visible light, which can boost the activity of the photocatalysts and the utilization of the sunlight. UC materials also open a new shortcut route for the development of photocatalyst materials which could solve the problem that wide bandgap semiconductors have a narrow light response range.