The ability of silver-biochar green-synthesized from Citrus maxima peel to adsorb pollutant organic compounds and antibacterial activity

Abstract

Citrus maxima peel (CMP) was utilized for the green synthesis of multifunctional silver-biochar material (Ag-CMPB). An alternative, cost-effective and eco-friendly technique was performed using the CMP extract as a reducing agent for the biosynthesis of Ag-CMPB material, in which biochar is prepared from CMP residue. Ag-CMPB nanomaterials were characterized by various physico-chemical methods such as XRD, HRTEM, BET, FT-IR, EDX, and PZC. The results revealed the formation of the face-centered cubic structure of Ag with the particle size in a range of 3 − 10 nm and the stacking structure of layers of biochar. Flavonoids and phenolic acids in CMP extract as a reducing agent of Ag-CMPB material. The specific surface area of Ag-CMPB was determined to be 79.2 m2/g with a pore diameter of 22.4 Å. Ag-CMPB showed high efficiency in the short time in removing organic compounds. The adsorption efficiency was recognized in the following sequence for POPs adsorption: Methyl blue > Rhodamine B > Methyl orange, with the adsorption capacities of 95.5, 69.3, and 51.5 mg/g, respectively. The antibacterial activity of Ag-CMPB was evaluated on five bacteria against B. cereus, E. coli, P. aeruginosa, S. aureus, and Salmonella by the zone of inhibition and MIC value.