Impact of Polymorphism vs Shape of Titania Nanocrystals towards Hydrogen Evolution Reaction

In this report, we investigated the impact of polymorphism vs dimension control of titania nanocrystals towards hydrogen generation. Two different forms of titania nanoparticles have been synthesized following solvothermal method leading to the formation of two distinct physicochemical features. Detail structural, morphological, and optical studies revealed the formation of titania nanorods correspond to rutile while granular particles correspond to anatase phase. Among various titania polymorphs anatase is well known for superior photocatalytic activity but to our surprise, the as-synthesized rutile nanorods exhibited higher catalytic activity in comparison to anatase spheres and hydrogen evolution was significantly enhanced after addition of diminutive amount of Pt as co-catalyst. Thus, despite of higher catalytic activity of anatase, the enhanced hydrogen evolution of rutile nanorods may be related to the creation of a1D structure. Our study highlights the importance of considering not only TiO2 polymorphism, but also shape and dimension, in optimizing photocatalytic H2 production.