Investigating the efficacy of CeO2 multi-layered triangular nanosheets for augmenting cathodic hydrogen peroxide production in microbial fuel cell

The current investigation deals with the synthesis of multi-layered triangular nanosheets of CeO2 with a quasi-planar geometry and its application as a cathode catalyst for accelerated cathodic reduction of O-2 to H2O2 in a dual chamber microbial fuel cell (MFC) treating simulated domestic wastewater. The unique structure of CeO2 facilitated local storage of oxygen at nanoscale level and high oxygen reduction activity as evident from the cyclic voltammogram, which enabled a higher rate of cathodic H2O2 electrosynthesis. The MFC containing CeO2 catalyst (MFC-CAT) exhibited the highest H2O2 production of 221.4 +/- 18.94 mg L-1 in 24 h; while the MFC with bare carbon electrode (MFC-C) exhibited 133.4 +/- 11.16 mg L-1 under similar operating conditions. The highest specific H2O2 yield achieved with an influent COD of 1000 mg L-1 in the anodic chamber and an external resistance of 10 Omega was 13.16 +/- 2.22 mg L-1 h(-1) at the end of 4 h for MFC-CAT. The power density of 179.23 mW m(-2) was observed for MFC-CAT in the same operational stage. In comparison, MFC-C exhibited a maximum specific H2O2 yield of 7.44 +/- 0.89 mg L-1 h(-1) for a retention period of 8 h and a power density of 96.1 mW m(-2). Results of the present investigation revealed that synthesized ceria as cathode catalyst can facilitate a higher yield of H2O2 in the catholyte, while simultaneously enhancing the electrical performance compared to bare carbon catalyst. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study focused on synthesizing CeO2 nanosheets as a cathode catalyst for microbial fuel cells to accelerate the reduction of O-2 to H2O2. CeO2 catalyst with a unique structure showed increased H2O2 production and enhanced electrical performance compared to bare carbon catalyst.