Synthesis of novel visible light driven MgO@GO nanocomposite photocatalyst for degradation of Rhodamine 6G

In this study, a novel nanocomposite of magnesium oxide doped graphene oxide (MgO@GO) visible-light driven photocatalyst was successfully synthesized for model Rhodamine 6G (Rh6G) degradation. This photocatalyst was comprehensively investigated to justify the morphology, structure, functional groups and chemical composition by Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT -IR) and SEM-Energy-Dispersive X-ray Spectroscopy (SEM-EDS mapping). Four different methods were initially studied i.e. sun light, tungsten light (50 W), stirring and aeration separately for degradation of Rh6G (30 mL of 1 ppm) and obtained results as 33%, 61%, 25% and 7% within 6 h respectively. The new method was developed for combination of different techniques to achieve high efficiency of photocatalyst. The combination of three methods i.e. tungsten light (50 W), stirring (450 rpm) and aeration (4 L/min) delivered 98% degradation of Rh6G (30 mL of 1 ppm) within 15 min without any aid of scavenger. This is due to excellent enhancement of favorable photo-generated holes, hydroxyl radicals and higher photocurrent response intensity of MgO@GO compared to MgO and GO. It also reflects the synergistic effect of GO to enhance the charge separation efficiency. Addi-tionally, a comparative evaluation of the photodegradation performance of MgO@GO, MgO and GO nano -materials was also carried out. This work reveals that, a rational combination of GO and MgO can lead the efficient photocatalytic degradation of recalcitrant organic pollutants such as Rh6G.