Advanced chemical analysis by the X-ray photoelectron spectroscopy (XPS) corroborated the EDX results. Despite a significant reduction of oxygen content, we still observed a considerable fraction of C-O and C=O surface functional groups (Fig. ). These hydrophilic functional groups are desirable to retain good wettability and could serve as anchor points for surface functionalization. Mercury porosimetry further revealed that the cellulose paper and LIG-E exhibit nearly identical mean pore sizes (11 μm), with a small degree of distribution broadening (Fig. ). The conservation of cellulose wetting and mesoporous properties after laser pyrolysis makes LIG-E extremely promising for applications in capillary-driven electrofluidic systems.