Title : Particulate photocatalyst sheets for scalable Z scheme photocatalytic water splitting
Abstract:
Owing to the energy and environmental issues become more apparent on a worldwide scale, a transition of energy supply from conventional fossil fuels to a more promising carrier, namely hydrogen (H2), is anticipated in the near future. Photocatalytic water splitting is one of the many endeavors in harvesting H2 fuel using the abundant energy from the Sun. Cutting edge research within the field focuses on the biomimetic artificial Z-scheme photocatalysis which comprises of the ingenious arrangement of a HEP (PS I) and an OEP (PS II) connected by an electron mediator. As of recent, scalable photocatalytic water splitting has been witnessed in particulate photocatalyst sheets inspired by Z-schematic HEP-conductive layer-OEP system. One of the major challenges in developing an efficient Z-scheme photocatalyst sheets is establishing efficient interparticle electron transfer between HEP and OEP, which are embedded on the conductive layer. A proof-of-principle demonstration on Z-scheme particulate photocatalyst sheets system speculates that the HEP-OEP layers often thickly stacked on the conductive layer, which greatly suppress the electron relaying within the system. In this study, the implication of nitrogen-doped carbon nanotubes (N-CNTs) was investigated as conductive mediator layer to bridge twinned Zn0.5Cd0.5S (HEP) and Bi4NbO8Cl (OEP) in Z-scheme photocatalytic water splitting. Annealing of the HEP-OEP layers on N-CNTs sheet and surface modification was done to improve electron transfer within the particulate sheets. The optimized particulate photocatalyst sheets exhibited outstanding overall water splitting to yield 10.8 ??mol h-1 of H2 and 5.2 ??mol h-1 of O2 under simulated solar light irradiation. In all, these findings could extend the electron mediator candidates to a larger horizon and pave way in future solar energy augmentation.
