Role of hydroxylation modification on the structure and property of reduced graphene oxide/TiO2 hybrids

Abstract To extend the spectra response of TiO 2 and enhance its photocatalytic activity, surface modification and catalyst supporter have attracted great attention. In this report, a simple and versatile approach has been developed to hydroxylate the reduced graphene oxide/TiO 2 hybrids (OH-rGO/TiO 2 ) by UV-microwave method, and the enhanced mechanisms of hydroxylation were analyzed in details. Experimental results show that TiO 2 nanocrystals@OH-TiO 2 heterojunctions formed on rGO sheets in situ by UV/H 2 O 2 process. Hydroxylation not only can induce many surface defects (Ti 3+ , O vacancy and Ti-OH) on the surface of TiO 2 , but also change the color into yellow and strengthen the interaction between rGO and TiO 2 . OH-rGO/TiO 2 hybrids showed excellent durability for high-concentration dyes, and exhibited strong adsorbability and photocatalytic activity. These enhancements are attributed to the excellent property of rGO and surface defects of TiO 2 induced by hydroxylation, which expand the light absorption up to 600 nm, benefit to the self-dispersion of hybrids, and improve the adsorption dynamic and charge transfer with lower carrier’s recombination.