Simultaneous layer exfoliation and defect activation in g-C<sub>3</sub>N<sub>4</sub> nanosheets with air–water interfacial plasma: spectroscopic defect probing with tailored optical properties
Trishamoni Kashyap, Palash Jyoti Boruah, H. Bailung, Dirtha Sanyal, Biswajit Choudhury
Abstract
. The thickness becomes 3.78 nm after 150 min of plasma treatment. The exfoliated layers emerge with nitrogen-vacancy sites and self-incorporated defects as probed by positron annihilation spectroscopy (PAS) and X-ray photoelectron spectroscopy (XPS). The defect activated layers show visible light absorption extended up to 600 nm. It is demonstrated that a non-uniform change in the band gap with the plasma treatment time results from quantum confinement in thin layers and Urbach tailing due to defects acting in opposition. Further, steady-state and time-resolved spectroscopy shows the contribution of multiple defect sites for a prolonged lifetime of photoinduced carriers. These defect-activated ultrathin nanosheets of CN serve as an active photocatalyst in the degradation of rhodamine B (RhB) under white LED illumination.