Green reduction of graphene oxide using Bacillus sphaericus

Area of Science:

• Materials Science
• Green Chemistry
• Biotechnology

Background:

• Chemical reduction of graphene oxide (GO) to reduced graphene oxide (RGO) often employs toxic reagents, posing environmental concerns.
• There is a need for sustainable and eco-friendly methods for RGO production.

Purpose of the Study:

• To develop a green and efficient method for reducing graphene oxide (GO) to reduced graphene oxide (RGO) using a microorganism.
• To characterize the synthesized RGO and confirm the effectiveness of the biological reduction process.

Main Methods:

• Utilized Bacillus sphaericus for the biological reduction of graphene oxide (GO).
• Employed advanced characterization techniques: UV-vis, XRD, FTIR, Raman spectroscopy, XPS, and SEM-EDS to analyze the reduction process and product.
• Evaluated the conductivity of the resulting reduced graphene oxide (RGO) using cyclic voltammetry (CVs).

Main Results:

• Successful reduction of GO to RGO was confirmed by UV-vis (new peak at 261 nm) and XRD (new peak at 2θ = 24.6°).
• Raman spectroscopy indicated successful reduction with an increased D band to G band intensity ratio (0.99 to 1.17).
• FTIR and XPS confirmed the reduction of specific functional groups (OH, CO, COC), and CVs showed good conductivity of the produced RGO (0.8 to 1.1 mW·cm⁻²).

Conclusions:

• Bacillus sphaericus facilitates a green and straightforward method for synthesizing reduced graphene oxide (RGO).
• This microbial reduction offers an environmentally benign alternative to conventional chemical reduction methods for RGO production.