Efficient photocatalytic degradation of methylene blue by using GO/hemin/TiO ₂ nanocomposite under visible irradiation

Abstract

A hybrid photocatalyst with high photocatalytic activity under visible light was developed. The photocatalystgraphene oxide (GO)/hemin/ titanium dioxide (TiO 2) nanocomposite was prepared by a simple method via adsorption at room temperature within 3 h, and was characterised using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and UV-Vis spectroscopy. The results show that TiO 2 nanoparticles were dispersed on the surface of GO sheets uniformly, and the crystal structure remained the same as original anatase TiO 2 phase in the presence of GO and hemin. Extended absorption of the nanocomposite into the visible region is benefit for the novel hybrid photocatalyst to utilise visible light more efficiently in the photocatalytic reaction. The photocatalytic activity increased about 70% in the presence of GO and hemin (96%) comparing to pure TiO 2 (26%). The nanocomposite catalyst could stably adsorb and degrade methylene blue of different concentration without H 2 O 2 or sacrificial electron donor at a relatively wide range of pH values within 3 h. As well as, the prepared GO/hemin/TiO 2 nanocomposite shows good stability and reusability in the photocatalytic reaction, enabling it a potential application in wastewater treatment.

Study on dynamic scaling of morphological evolution of TiO 2 film deposited with different O 2 /Ar flow ratio

“…Especially in 1972, Fujishima and Honda [3] initially found that TiO 2 could split the water into the oxygen and hydrogen after irradiated by the solar light. Then, many researchers focused on the preparation of TiO 2 with photocatalysis property [4][5][6][7][8]. Toyoda et al [9] researched the influence of the substrate on the crystal structure and photocatalysis property of TiO 2 film.…”