Biogenic synthesis of argentum nanocomposites for visible light photocatalyst of dye degradation

Abstract

In the current study, Silver-Activated carbon (Ag-AC) nanocomposites were synthesized by a green method using the leaf extract of Baccaurea motleyana and activated carbon obtained from the dried seeds of Baccaurea motleyana. The biomolecules present in the Baccaurea motleyana act as a complexing as well as a capping agent. The size and band gap energy of the synthesized Ag-AC nanocomposite were found to be 4.5 nm and 2.1 eV, respectively. Methylene Blue (MB) and Rhodamine B (RhB) is a widely used dye which is detected both in wastewater and in sewage treatment plant effluents. The synthesized Ag-AC nanocomposite shows an invincible photocatalytic property in the degradation of dyes and textile waste water under Xenon light. The results showed that 88.02 % of MB dye and 80.74 % of RhB. Additionally, the textile effluent treatment discovered that the Ag-AC catalyst degraded up to 93.42 % within 150 min and prominently decreased the levels of certain physicochemical parameters of textile effluents. The degradation of both the dyes follows a pseudo-first-order reaction and the rate of the constant (k) of photodegradation was found to be 0.0218 min−1 and 0.0137 min−1 for MB and RhB dye. This study reveals that the synthesized Ag-AC nanocatalyst is an excellent photocatalyst for the photodegradation of dyes and textile wastewater due to the synergistic effect of Ag nanoparticles in photocatalysis and activated carbon in adsorption of pollutants. The Ag-AC nanocomposite can be recycled and used for upto 4 cycles without any significant alteration in the photocatalytic activity.