Fabrication of exfoliated graphitic carbon nitride, (g-C3N4) thin film by methanolic dispersion

This paper reports the successful exfoliation of nanosheets from bulk g-C3N4 by using urea as a precursor. The alteration from bulk g-C3N4 powder, changed its semiconductor arrangements such as the optical absorption, chemical bonding, and topography images. A slow direct low thermal treatment (∼40 °C, 24 h) was proposed as a formation of a thinner layer by layer, complete and effective polymerization for an exfoliated g-C3N4. The photocurrent responses were more than two times higher for exfoliated g-C3N4 compared with bulk g-C3N4, reaching ∼4.37 μA cm−2 up to 10.21 μA cm−2 at 1.23 vs. (Ag/AgCl). This fabrication method involved dispersing of the highly stable g-C3N4 suspension onto FTO surface via spin coating, followed by a moderate post-annealing temperature at 350 °C. The monolayer g-C3N4 act as a photoelectrode, responding to light and dark current, and maintained its own intrinsic n-types properties. The interaction of the C and N atom with molecules of methanol (CH3OH) followed with vibration force (ultrasonication) produces the ultrafast drying and can transmit to disrupt the van der Waals forces within the g-C3N4 structure. Therefore, due to the ability the good performance, the exfoliated g-C3N4 can be envisioned as a potential application such as water splitting, solar cell, and environmental remediation. •The introduction of low direct thermal treatment (40°) for bulk g-C3N4 and Urea as a precursor.•Methanol was chosen due to the excellent dispersion method in the fabrication of a uniform thin film.•The modification via ultrasonication (vibration force) reinforced the Wan der Waals forces inside the exfoliated g-C3N4.•FT-IR signal exhibited a broad/strong crystalline peak, representing an enhanced chemical bond network in exfoliated g-C3N4.•The exfoliated g-C3N4 thin-film yielded the optimum photocurrent density reaching 10.21 μA cm−2 at 1.23 V versus Ag/AgCl.