Hydrothermal synthesis of titanium dioxide/graphene aerogel for photodegradation of methylene blue in aqueous solution
Truong Thi Phuong Nguyet Xuan Trinh, Nguyễn Thị Hương Giang, Le Minh Huong, Doan Ba Thinh, Nguyen Minh Dat, Dinh Ngoc Trinh, Nguyễn Duy Hải, Đoàn Thị Yến Oanh, Hoàng Minh Nam, Mai Thanh Phong, Nguyễn Hữu Hiếu
Abstract
Titanium dioxide/graphene aerogel (TiO2/GA) was synthesized via a one-pot hydrothermal method and characterized by various spectroscopic techniques, including X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscope, transmission electron microscopy, Raman spectroscopy, and UV-Vis spectroscopy. The influences of pH and TiO2/GA dose on the photocatalytic performance were investigated against positive dye methylene blue (MB) under UV light control. The characterization of TiO2/GA revealed that the synthesized TiO2 nanosize of 12–22.5 nm was uniformly distributed onto the graphene layers. The bandgap of the as-prepared nanocomposite was 2.63 eV, lower than that of pure TiO2 (3.2 eV). The kinetic studies exhibited that the adsorption–desorption equilibrium was achieved after 60 min following the pseudo-second-order. Meanwhile, 99.9% of MB was eliminated after 120 min at pH 9 with a 20 mg catalyst. The degradation data were well fitted to the pseudo-first-order kinetic model. Accordingly, applying TiO2/GA as an efficient photocatalyst indicates a potential pathway for the degradation of organic contaminants in wastewater treatment.