Graphene oxide enhanced amine-functionalized titanium metal organic framework for visible-light-driven photocatalytic oxidation of gaseous pollutants

Graphene oxide (GO) enhanced amine-functionalized titanium metal organic framework (NH2-MIL-125(Ti)) was fabricated via a facile microwave solvothermal process by using GO, C12H28O4Ti, and 2-aminoterephthalic acid as precursors. Under the microwave irradiation, the surface of GO could act as the microwave antenna for fast absorbing microwave energy with the formation of hot-spots on GO (hot-spots effect). These hot-spots allowed both the well-crystallization of NH2-MIL-125(Ti) crystals with a highly dispersity on the surface of GO and the strong interaction between NH2-MIL-125(Ti) and GO, supported by various characterization such as XRD, Raman, UV-vis and so on. Benefiting from the strong interaction and high electronic conductivity of GO, such GO/NH2-MIL-125(Ti) hybrid exhibited a greatly enhanced metal organic framework crystallinity, visible-light absorption, photocurrent intensity, electron carrier density and a lower photo-generated electron-hole recombination rate, compared to the pure NH2-MIL-125(Ti). Therefore, the as-obtained hybrid system was proved highly efficient for photocatalytic oxidation of gaseous pollutants, such as nitric oxide (NOx) and acetaldehyde with long durability, under visible light (lambda > 420 nm) irradiation.