Green Synthesis of Reduced Graphene Oxide Using the Tinospora cordifolia Plant Extract: Exploring Its Potential for Methylene Blue Dye Degradation and Antibacterial Activity

ACS Omega. 2024 Apr 24;9(18):20304-20321. doi: 10.1021/acsomega.4c00748. eCollection 2024 May 7.

Abstract

Graphene has attracted significant attention recently due to its unique mechanical, electrical, thermal, and optical properties. The present study focuses on synthesizing green rGO using the Tinospora cordifolia plant extract by mixing it in a suspension of graphene oxide. The plant extract of T. cordifolia acts as a reducing agent and is cost-effective, renewable, and eco-friendly. Green-synthesized rGO (G-rGO) was characterized using FTIR, HR-SEM, EDX, and HR-XRD analyses. G-rGO consists of nanosheets with an average width of approximately 30 nm. G-rGO has a range of hydrodynamic radius (270-470) nm and an average ζ potential of -29.9 mV. Further, G-rGO was used as a nanoadsorbent for optimal exclusion of methylene blue (MB) dye using the response surface methodology (RSM). Adsorption results confirmed 94.85% MB dye removal with 58.81 mg g-1 adsorption capacity at optimum conditions. The G-rGO's antibacterial activity was also tested against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria, finding the exhibited zone of inhibition of 10, 11, and 15 mm and 10, 13, and 17 mm at 20, 40, and 80 μg mL-1 concentrations of G-rGO, respectively.