Heterogeneous photocatalytic degradation of pharmaceutical 5-HT receptor agonist rizatriptan benzoate using nanocrystalline TiO2

Department of Chemistry, Dr. APJ Abdul Kalam University, Indore-452 016, Madhya Pradesh, India Department of Chemistry, Jiwaji University, Gwalior-474 011, Madhya Pradesh, India E-mail: swatipc2011@gmail.com Manuscript received online 13 October 2020, revised and accepted 31 November 2020 Water pollution due to pharmaceuticals and personal care products (PPCPs) has been gaining attention of researchers all over the world. The heterogeneous photocatalytic degradation in the presence of semiconductor and UV radiation has been getting much more attention because it is an efficient, inexpensive, eco-friendly method and doses not left any waste material in water/wastewater. In the present study, photocatalytic degradation of rizatriptan benzoate (RTB) has been investigated using titanium dioxide (TiO2 ) photocatalyst. The photocatalytic degradation activity of the nanocatalyst has been evaluated on the basis of Langmuir kinetic model. The effects of pH, concentration of H2O2 added, initial drug concentration and dosage of the catalyst have also been investigated. The best possible conditions for the degradation of the drug have been evaluated and found drug concentration 0.3 mg/mL, pH 11.5, and dose of catalyst 10 mg was optimum for this experiment. The effect of hydrogen peroxide on the degradation process was also done to study the effect of the electron acceptor and it was found that in the following process generation of hydroxyl radicals and retardation of electron-hole recombination both takes place. It was found by this study that photocatalytic degradation by titanium dioxide is a proficient, cost-effective and more rapidly form of degradation rizatriptan benzoate from aqueous solution.