Catalytic performance of rGO-Zeolite modified anode in clay biophotovotaics system for effective urine treatment

Low power output due to poor anode kinetics is minimized by modifying the anode with rGO-Zeolite to improve the electrochemical redox reactions in biophotovoltaics (BPV). Higher power production and N/P-recovery is successfully achieved in horizontal Torch separator-based urine fed BPV modified with rGO-Zeolite anodes than bare graphite anode. Among the two variants of anodes, modified anode results in power of 146.88 mW/m2, redox current of 18.9 mA, Phosphorous (88 +/- 0.3%), NH4+-N (49 +/- 0.5%), and Coulombic efficiency of 15.16 +/- 0.3%. Improvement in power output is due to the higher electroactive surface area provided by rGO-Zeolite anode for electron transfer. Recovery of clear cath-olyte (8 ml/day) during human-urine treatment and energy recovery for operating the hygro-clock are the main key features of low-cost BPV. Thus, BPV with modified anodes serves as a sustainable technology for recovering energy and resources from human urine and makes it suitable to use for onsite urine treatment and sanitation applications. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Low power output in biophotovoltaics (BPV) due to poor anode kinetics is minimized by modifying the anode with rGO-Zeolite, which improves electrochemical redox reactions. Horizontal Torch separator-based urine fed BPV with rGO-Zeolite anodes achieve higher power production and N/P-recovery compared to bare graphite anodes. The modified anode results in a power output of 146.88 mW/m2, redox current of 18.9 mA, and significant recovery of Phosphorous and NH4+-N.