Solvent and surfactant modulated diversification of Gd2MoO6 nanostructure for optimizing photodegradation of amphetamine under visible light and photoelectrochemical study

Abstract

The effectiveness of nanomaterials has opened up new horizon towards their application as heterogeneous photocatalysts. A novel nanocatalyst Gd2MoO6 is developed by employing different solvents and capping agent to observe its catalytic activity towards pharmaceutical waste degradation under visible light irradiation. Two organic solvents, dimethyl formamide (DMF) and ethylene glycol (EG) were used in four different synthesis routes to demonstrate the morphological diversification and nucleation mechanism of the said nanocatalyst. The effect of surfactant assisted synthesis on morphology, texture and opto-electronic properties of as-prepared nanocatalyst was studied. Rigorous characterization techniques were carried out to establish the robust charge transfer mechanism as well as degradation kinetics. The addition of CTAB helped to evolve ultrathin nanoflakes like morphology while using DMF, whereas broken agglomerated diffused morphology was found in EG-based route. The role of oxygen vacancy based surface defect towards trapping of more charge carriers are also established in this work. The optical characteristics were identified by UV–VIS spectrum of as-prepared samples which revealed the more optimized band gap of samples towards visible light. The computational study via Density Functional Theory calculation verified its optoelectronic properties with the experimentally obtained one. Along with high crystallinity and better electrochemical property, Gd2MoO6 nanoflakes were able to show outstanding photodegradation ability by degrading amphetamine, a complex hazardous drug to more than 97%. The possible degradation pathway was also defined by the LC-MS/MS analysis. The developed catalysts also showed excellent results in photoelectrochemical water splitting generating a current density of 5.87 mA/cm2.