A nanoscale observation to explain the discrepancy of electron exchange capacities between biochar containing comparable surface redox-active moieties

Abstract

Highlights The microscopic distribution of RAMs on biochar was achieved by combining C-AFM and a mediated electrochemical method. The uneven distribution of RAMs enabled biochar to possess outstanding EEC by enhancing accessibility. The removal of submicron particles that only occupied 1-4‰wt reduced EDC to 72% for st700 and 53% for ind400. The removal of submicron particles changed the EAC of st700 to 87% and ind400 to 1.40 times as raw chars. Condensed aromatic structures were indispensable to EAC, while both heteroatoms and amorphous aromatics contributed to EDC.

Keywords

• Biochar
• Pyrogenic chars
• Redox property
• Electron exchange capacity
• C-AFM