Highly effective degradation of imidacloprid by H2O2/ fullerene decorated P-doped g-C3N4 photocatalyst

Abstract

In this work, P-doped g-C3N4 (PCN) was coupled with another conducting material, fullerene (C60). P doping led to an expansion in solar-light-responsive range, prolongation in charge carrier lifetime, facilitation in charge separation, and transportation, while on the other hand, C60 captured electrons from PCN and reduced the recombination of charge carrier. C60/PCN nanocomposites (with different C60 ratios) were successfully synthesized via a simple ultrasonic method for imidacloprid (IMI) pesticide degradation. Raman and N2-adsorption-desorption measurement techniques were implemented to scrutinize structural properties and the successful formation of the nanocomposite. The photocatalytic degradation of IMI signified a loading of 0.04 wt.% amount of C60 as its optimal concentration. Through Brunauer–Emmett–Teller (BET) isotherm, two times larger specific surface area was observed in 0.04 wt.% C60/PCN than PCN. 60 mg/mL and 1 × 10−4 M were witnessed as an optimal catalyst dose and pesticide concentration at pH 4. Addition of H2O2 enhanced photodegradation processes since it also served as a good electron acceptor, which boosted charge carrier separation. Photodegradation results confirmed that 0.04 wt.% C60/PCN/H2O2 and 0.04 wt.% C60/PCN nanocomposites exhibited 95 % and 91 % removal efficiency, respectively, which were higher than the percentages exhibited by other tested photocatalysts. A promising mechanism of C60/PCN nanocomposite against IMI degradation was also proposed, validating the role of h+, O2− and OH radicals in the photocatalytic process.