Biogenic synthesis of SnO2/activated carbon nanocomposite and its application as photocatalyst in the degradation of naproxen

Abstract In the current study, SnO2/Activated carbon (SnO2/AC) nanocomposites were synthesized by hydrothermal method using SnCl4·5H2O, Saccharum officinarum juice and activated carbon obtained from the dried stem of Corchorus olitorius. The biomolecules present in the Saccharum officinarum acts as a complexing as well as a capping agent. The size and band gap energy of the as-synthesized SnO2/AC nanocomposite were found to be 3 nm and 3.6 eV, respectively. Naproxen (NPX) is a widely used nonsteroidal anti-inflammatory drug which is detected both in waste waters and in sewage treatment plant effluents. The synthesized SnO2/AC nanocomposite shows an invincible photocatalytic property in the degradation of naproxen under direct sunlight. The results showed that 94% of NPX was degraded within 2 h. The degradation of NPX follows pseudo-first-order reaction and the rate of the constant (k) of photodegradation was found to be 2.5 × 10−2 min−1. Various parameters, such as effect of catalytic loading, initial concentration, pH and contact time were also studied for optimization of the photocatalyst in the photodegradation process. This study reveals that the synthesized SnO2/AC nanocatalyst is an excellent photocatalyst for the photodegradation of naproxen from wastewater of pharmaceutical industries due to the synergistic effect of SnO2 nanoparticles in photocatalysis and activated carbon in adsorption of pollutants. The SnO2/AC nanocomposite can be recycled and used upto 5 cycles without any significant alteration in the photocatalytic activity.