Sharma, Aditya Varshney, Mayora Chae, Keun Hwa Won, Sung Ok 2024-01-19T21:32:05Z 2024-01-19T21:32:05Z 2021-09-05 2018-11 1567-1739 https://pubs.kist.re.kr/handle/201004/120746 An improved method for the preparation of g-C3N4 is described. Currently, heating ( > 400 C degrees) of urea is the common method used for preparing the g-C3N4. We have found that sonication of melamine in HNO3 solution, followed by washing with anhydrous ethanol, not only reduce the crystallite size of g-C3N4 but also facilitate intriguing electronic structure and photoluminescence (PL) properties. Moreover, loading of metal (Pt and Ag) nanoparticles, by applying the borohydride reduction method, has resulted in multicolor-emission from g-C3N4. With the help of PL spectra and local electronic structure study, at C K-edge, N K-edge, Pt L-edge and Ag K-edge by X-ray absorption spectroscopy (XAS), a precise mechanism of tunable luminescence is established. The PL mechanism ascribes the amendments in the transitions, via defect and/or metal states assimilation, between the pi* states of Iris-triazine ring of g-C3N4 and lone pair states of nitride. It is evidenced that interaction between the C/N 2p and metal 4d/5d orbitals of Ag/Pt has manifested a net detraction in the delta*-> LP transitions and enhancement in the pi*-> LP and pi*->pi at transitions, leading to broad PL spectra from g-C3N4 organic semiconductor compound. English ELSEVIER SCIENCE BV GRAPHITIC CARBON NITRIDE PHOTOCATALYTIC ACTIVITY GRAPHENE-OXIDE SPECTROSCOPY NANOCATALYST XANES EXAFS Mechanistic investigations on emission characteristics from g-C3N4, g-C3N4@Pt and g-C3N4@Ag nanostructures using X-ray absorption Article 10.1016/j.cap.2018.08.019 1 CURRENT APPLIED PHYSICS, v.18, no.11, pp.1458 - 1464 CURRENT APPLIED PHYSICS 18 11 1458 1464 scie scopus kci ART002406924 000446676900048 2-s2.0-85053025363 Materials Science, Multidisciplinary Physics, Applied Materials Science Physics Article GRAPHITIC CARBON NITRIDE PHOTOCATALYTIC ACTIVITY GRAPHENE-OXIDE SPECTROSCOPY NANOCATALYST XANES EXAFS g-C3N4 XRD Raman XANES PL