Graphene supported ceria-titania mixed oxide composite-An effective photo catalyst for methylene blue (MB) dye degradation

In the present study we have prepared graphene supported CeO2-TiO2 mixed oxide and studied its activity towards photocatalytic degradation of methylene blue (MB) dye. The mixed oxide is prepared with the variation of cerium loading to that of titanium from 2% to 10% by sol-gel method and graphene oxide (GO) is prepared by using modified Hummer's method. The resulting adsorbent nanocomposite is synthesised by chemical reduction method with GO loading 2% by weight to that of mixed metal oxide and employed in the catalytic process through batch wise adsorption to test the optimum level of activity by varying the parameters (pH: 3-10, time: 15-75 min, dye concentration: 5-40 ppm, anions like Cl-, SO42-, NO3-, HCO3-) with catalyst loading 0.020 g per 0.100 L of the dye solution. It is inferred that the adsorbent catalyst nanocomposite with ceria loading up to 5% with that of titania has better catalytic activity towards the photodegradation of MB with the optimum condition of pH-10 and time-75 minutes. Degraded product characterisation is carried out by LC-MS technique, which confirmed the degradation of MB. The adsorption kinetics is being investigated through pseudo-first-order kinetics and Langmuir adsorption model with good fitting having R2 value 0.986 and 0.993 respectively.