Valorising lignocellulosic biomass to high-performance electrocatalysts via anaerobic digestion pretreatment

Abstract

Anaerobic digestion (AD) was initially evaluated as a potential preprocessing method for preparing biomass-based carbon electrocatalysts in this study. The AD pretreatment succeeded in the structural depolymerization and nitrogen enrichment of Hybrid Pennisetum, which provided favorable conditions to achieve efficient and homogeneous nitrogen introduction due to microorganism community enrichment and provided a porous structure by degradation of the biodegradable components. The resulted biochar exhibited improved physiochemical properties including higher specific surface areas, nitrogen content and graphitization degree than that obtained from pyrolyzing raw biomass. These improvements were positively correlated with the AD time and showed to have enhanced the performance in oxygen reduction reaction and practical microbial fuel cell applications. Amongst the investigated samples, the obtained biochar pretreated by AD for 15 days exhibited the most excellent performance with an onset potential of 0.17 V (VS. saturated calomel electrode) and the maximal power density of 543.2 mW cm−2 assembled in microbial fuel cells. This study suggested applying AD as a new biological pretreatment in the preparation of biomass-based electrocatalysts, and provided a unique pathway for fabricating high-performance biochar-based catalysts by structure optimization and N-containing active sites construction via gentle biological method, thereby providing a cost-effective method to fabricate metal-free catalysts for oxygen reduction reaction. Graphical Abstract

Green algae Ulva lactuca-derived biochar-sulfur improves the adsorption of methylene blue from water

“…This includes effectively fractioning dyes and salts using ultrafiltration membranes 20 . Besides, the use of materials like red mud, eggshells, and biochar has been explored for the removal of specific dyes from wastewater, highlighting the versatility of adsorption processes 21 – 23 . The potential of biochar for removing organic and inorganic pollutants from industrial effluents has been highlighted, emphasizing its versatility and effectiveness in wastewater treatment 24 – 27 .…”

Study of the Suitability of Corncob Biochar as Electrocatalyst for Zn–Air Batteries

“…Biochar electrode studies have become very popular in the last few years since the use of an abundant, inexpensive material originating from residual biomass is very attractive. Some applications like direct carbon fuel cells and supercapacitors have been reported [34][35][36][37][38]. The high SSA is a desirable characteristic but not crucial for the efficiency of the electrode.…”

Synergistic Advancements in Battery-Grade Energy Storage: AgCoS@MXene@AC Hybrid Electrode Material as an Enhanced Electrocatalyst for Oxygen Reduction Reaction

“…Increasing one or both of these values is going to result in a considerable increase in the energy density of supercapacitors (SCs), as indicated by the formula E = 1 2 / CV 2 , where V is the operating voltage, C is the capacitance, and E is the energy density. [14][15][16] As a result, there have been many recent studies on improving the energy storage efficiency of supercapacitors (SCs) deprived of sacrificing their high-power densities. Hybrid supercapacitors are a highly effective and promising approach to increase the energy density of SCs.…”