Exposing TiO2 (001) crystal facet in nano Au-TiO2 heterostructures for enhanced photodegradation of methylene blue

This article reports an investigation on the effect of crystal facet of TiO2 in nano Au-TiO2 heterostructures for enhanced photocatalytic degradation of organic dyes. Here, nano Au-TiO2 heterostructures with two distinct TiO2 morphologies, i.e. nanospindles and nanocubes, were successfully prepared and utilized for photodegradation of methylene blue (MB). Based on the photocatalytic experiments, it is found that TiO2 nanospindles exhibited superior photocatalytic performance than TiO2 nanocubes which primarily due to the exposure of (001) crystal facet. It is observed that the exposure of (001) crystal facet was able to increase the photocatalytic reaction rate by four folds. Additionally, integration with Au nanoparticles was also found to have a synergistic effect in photodegradation activity due to the presence of surface plasmon resonance (SPR) effect. According to the result, Au-TiO2 nanospindles was found to be most efficient catalyst for photocatalytic degradation of MB with pseudo-first order reaction rate of 0.1570 min(-1).