Facilely prepared carbon dots as effective anode modifier for enhanced performance of microbial fuel cells

Abstract

Abstract Microbial fuel cells (MFCs) are a promising technology for obtaining energy in wastewater. Effective extracellular electron transfer is one of the key factors for its practical application. In this work, carbon dots (CDs) enriched with oxygen-containing groups on the surface were synthesized as an efficient anode modifier using a simple hydrothermal method and common reactants. The experimental results showed that CDs-modified anodes had higher electrical conductivity, and higher hydrophilicity, could load more microorganisms, enhanced electrochemical processes in the anode biofilm, and did not affect the total content of electrobacteria in the biofilm. The CDs-modified MFCs exhibited higher maximum power density (661.1 ± 42.6 mW m − 2 ) and open-circuit voltage (534.50 ± 6.4 mV), which were significantly better than those of the blank group MFCs (484.1 ± 14.1 mW m − 2 and 447.50 ± 12.1 mV). The use of simple carbon materials to improve the microbial loading on the MFCs anode and the electron transfer between the microbial-electrode may provide a new idea for the design of efficient MFCs.

Key findings

• ▸CDs-modified anodes had higher electrical conductivity and hydrophilicity.
• ▸CDs-modified MFCs exhibited higher maximum power density and open-circuit voltage compared to blank group MFCs.
• ▸The use of CDs as an anode modifier did not affect the total content of electrobacteria in the biofilm.

Keywords

Identifiers

DOI

10.21203/rs.3.rs-3472564/v1

Journal

Research Square

Year

2023