Graphite-decorated TiO₂ nanotubes for enhanced photocatalytic H₂ evolution

Abstract

Photocatalysis over titanium dioxide (TiO 2 ) has become a forefront over the last few decades. Different TiO 2 nanostructures, for instance, nanotubes, nanoparticles, and nanosheets have become attractive for researchers to improve the sluggish charge transfer kinetics of pristine TiO 2 . Most recently, TiO 2 /carbon composites are gaining research interest due to the multifunctional properties of carbon-based materials (graphene, graphite oxide, etc.) that can cover most of the aspects of photocatalytic enhancement. We, thereby, report on the photocatalytic activity of one-dimensional TiO 2 nanotubes modified by carbon for efficient hydrogen evolution. The photocatalyst was prepared by decorating nanographite on the anodic TiO 2 nanocavities. The presence of nanographite on the nanocavities was confirmed by SEM and XPS analysis. The composite nanotubes demonstrated an enhanced photocatalytic activity due to the presence of graphite and its modification during UV illumination. Side by side with hydrogen evolution, this opened up a one-step direct modification of graphite. The graphite modification during UV illumination was validated by the presence of oxygenated groups in XPS and a higher I D /I G ratio in Raman analysis. The proposed work sought the correlation between the interaction of carbon materials and metal oxide and their synergetic catalytic activity under UV light illumination.