fig3
Figure 3. N2 adsorption/desorption isotherms of PBF, PBF@N, and PBF@N@S (A) and pore size distribution of the PBF@N@S (B) and PBF@N (C). PBF: Bare biochar fibers; PBF@N: N-doped porous biochar fibers; PBF@N@S: N, S dual-doped porous biochar fibers.
