A wood pulp sponge cleaning wipe as a high-performance bioanode material in microbial electrochemical systems for its vast biomass carrying capacity,large capacitance,and small charge transfer resistance

Microbial electrochemical systems are a promising green and sustainable technology that can transform waste into electricity.Improving conversion efficiency and lowering system costs,particularly for elec-trodes,are the primary directions that promote practical application.Cellulose sponges made from wood pulp have been industrially mass-produced in various application scenarios due to their porosity and green sustainability.In this study,the three-dimensional(3D)porous cellulose sponges carbon(CSC)was obtained by directly carbonizing cellulose sponges at different temperatures(600,700,800,900,1000,and 1100℃).It has been successfully used as a high-performance anode in microbial fuel cells(MFCs).The carbonization temperature significantly impacted the materials’specific surface area,con-ductivity,and capacitance.The greater the anode material’s carbonization temperature,the lower the charge transfer resistance and the higher the maximum power density(CSC-1100,4.1±0.1 W m^(-2)).The CSC-700's maximum power density(3.62±0.11 W m^(-2))was the highest power density reported to date among lignocellulose-based anodes with relatively low energy consumption.The pleated multilayer porous surface promotes microbial adhesion and can build thicker biofilms with the highest biomass of 2661±117μg cm^(-2)(CSC-1100)and containing 86%electrogenic bacteria(Geobacter).To investigate the effect of conducting polymers on the material’s surface,we introduced polyaniline and polypyrrole.We found that the CSC-1000/PPy bioanodes produced a maximum power density(4.18±0.05 W m^(-2)),slightly higher than of without polypyrrole-modified(CSC-1000,3.99±0.06 W m^(-2)),indicating that the CSCs anode surface had excellent electron transfer efficiency and could achieve the same amount of energy as the polypyrrole surface.This study introduced a promising method for fabricating high-performance anodes using low-cost,industrialized,and sustainable materials.

Electrosynthesis of H_(2)O_(2) through a two-electron oxygen reduction reaction by carbon based catalysts:From mechanism,catalyst design to electrode fabrication

Hydrogen peroxide(H_(2)O_(2))is an efficient oxidant with multiple uses ranging from chemical synthesis to wastewater treatment.The in-situ H_(2)O_(2)production via a two-electron oxygen reduction reaction(ORR)will bring H_(2)O_(2)beyond its current applications.The development of carbon materials offers the hope for obtaining inexpensive and high-performance alternatives to substitute noble-metal catalysts in order to provide a full and comprehensive picture of the current state of the art treatments and inspire new research in this area.Herein,the most up-to-date findings in theoretical predictions,synthetic methodologies,and experimental investigations of carbon-based catalysts are systematically summarized.Various electrode fabrication and modification methods were also introduced and compared,along with our original research on the air-breathing cathode and three-phase interface theory inside a porous electrode.In addition,our current understanding of the challenges,future directions,and suggestions on the carbon-based catalyst designs and electrode fabrication are highlighted.