Modified nanoarchitectonics of activated carbon derived from the Astragalus shrub for efficient photocatalytic degradation of methylene blue from water

Abstract

ABSTRACT In this study, the photocatalytic degradation of methylene blue (MB) dye was explored by applying biochar/Ag nanocatalyst.Biochar (activated carbon) was produced from the Astragalus shrub by a slow pyrolysis procedure. Preparation of biochar/Ag nanoparticles was performed using the sol-gel technique, and the physical properties of the prepared nanocatalyst were studied using BET, FTIR, XRD, FESEM, and EDX analyses. According to the analyses, Ag was successfully placed on the biochar particles.Investigations on the Ag/activated carbon (AC) ratio, initial concentration dye, lamp power, pH, catalyst dosage, and amount of H2O2 were conducted to acquire the highest removal efficiency of MB. The maximum degradation rate of MB dye was attained under optimal conditions, including initial dye concentration of 5 mg/L, pH 9, 20 mL of H2O2, 60 mg of AC/Ag nanoparticle dosage, and 100 min under 80 W lamp power. The highest MB dye degradation in the mentioned circumstances was achieved at 96.09%.The kinetic survey likewise represented that the elimination of MB dye using AC/Ag nanocatalysts follows the first-order model, and the optimum time for the photocatalytic removal procedure of methylene blue through biochar/Ag nanocatalysts is 100 min. The stability of the AC/Ag nanoparticles during five rounds was favourable, and only 5.79% of MB dye degradation yield was diminished.