Recent advancements in surface plasmon resonance and Schottky junction assisted photocatalytic water splitting of noble metal decorated Titania: A review

In the current global energy crises, green H2-production via photocatalytic water splitting is one of the emerging and sustainable techniques. Accordingly, engineering a promising photocatalyst for photocatalytic H2-production is crucial considering the key factors, – (i) charge carrier generation via higher photon absorption ability and (ii) effective charge carrier separations. Titania (TiO2) is one of the widely used semiconductors (SCs) which show great performance in photocatalysis among all other metal oxide SCs. However, due to the limitations of Titania, surface modification of Titania with noble metal (NM) nanoparticle (NP) is a promising technique which induces two significant phenomena on the modified system – (a) higher photon absorption due to the surface plasmon resonance (SPR) effect of NM NP and (b) effective charge carrier separation due to formation of Schottky junction in metal-SC contact. In this review an attempt has been made to understand impact of NM loading on photon absorption, band alignment at the junction, and phase transformation of Titania. Further reviews are performed to understand the role of NM loading and modification in physicochemical features of Titania on photocatalytic H2-production and optimal conditions are also discussed. The route of charge carrier transportation depends on the formation of Schottky barrier and high energetic plasmon electrons of NM NP. It was also observed that additional photo-generated charge carrier in the system due to higher plasmon energy of NM suppress the barrier height at the junction which strongly supports higher photocatalytic H2-production. This review opens up a platform for effective photocatalytic H2-production through the incorporation of all the benefits of NM loading in terms of shape, size, change in Titania phases and band alignment at the junction.