Synergistic gas-bubbling and oxidative exfoliation for the reproducible synthesis of mesoporous g-C3N4 2D nanosheets with enhanced physicochemical properties.
ULLAH, Sajjad; SILVA, Livia Eloy da; FERREIRA-NETO, Elias Paiva; MUNEEB, Mohammad; MAIA, Lauro June Queiroz; NICOLAI, Yaman Masetto; TEDESCO, Antônio Cláudio; MORAES, Luiz Alberto Beraldo de; OLIVEIRA JUNIOR, Marcos de; COSTA, Beatriz Helena; PARVEEN, Rashida; RIBEIRO, Sidney José Lima; GONÇALVES, Rogéria Rocha.
ULLAH, Sajjad; SILVA, Livia Eloy da; FERREIRA-NETO, Elias Paiva; MUNEEB, Mohammad; MAIA, Lauro June Queiroz; NICOLAI, Yaman Masetto; TEDESCO, Antônio Cláudio; MORAES, Luiz Alberto Beraldo de; OLIVEIRA JUNIOR, Marcos de; COSTA, Beatriz Helena; PARVEEN, Rashida; RIBEIRO, Sidney José Lima; GONÇALVES, Rogéria Rocha.
Abstract: 2D nanosheets of graphitic carbon nitride (g-C3N4) have emerged as promising metal-free photocatalyst. However, their reproducible preparation with a control of physiochemical properties is challenging, and the commonly used thermal polymerization method often leads to the formation of bulk g-C3N4 with faster e--h+ recombination and low surface area, which hinder its full photocatalytic potential. To address these limitations and obtain highly exfoliated and mesoporous 2D nanosheets of g-C3N4 (EmNs) with desirable physiochemical properties, we propose a facile and reproducible collaborative strategy, based on the synergistic use of ammonium salts as a dynamic gas template and oxidative exfoliation (OE). The prepared EmNs were characterized by an array of complementary analytical techniques including XRD, DRS, EPR, NMR, TEM, SEM-EDX, Raman Spectroscopy, LC-DAD-MS, and time-resolved photoluminescence (PL) measurements and their photoactivity was evaluated through photodegradation of rhodamine B (RhB) dye and 2,4-D herbicide as model pollutants. The proposed one-pot, two-steps thermochemical synthesis protocol not only leads to the preparation of thin (12 ± 3 nm) EmNs but also allows the tuning of their electronic structure, band gap, textural properties, nitrogen vacancies (N-vacancies), and photocatalytic response. Importantly, the band gap energy (Eg), specific surface area, number of N-vacancies, and lifetimes of charge carriers (63?69 ns in EmNs vs 47 ns in pristine g-C3N4) were all found to increase with increasing NH4Cl/melamine ratio and after OE treatment in a synergistic manner. Resultantly, the prepared g-C3N4 EmNs exhibited 4 times higher photoactivity (kobs. = 0.09 min-1) than pristine g-C3N4 (kobs. = 0.023 min-1). This one-pot, two-step collaborative strategy can be used as an optimized protocol for the reproducible preparation of thin, highly photoactive, and mesoporous g-C3N4 nanosheets with tailored and enhanced physicochemical properties for desired applications.
@article={003293731,author = {ULLAH, Sajjad; SILVA, Livia Eloy da; FERREIRA-NETO, Elias Paiva; MUNEEB, Mohammad; MAIA, Lauro June Queiroz; NICOLAI, Yaman Masetto; TEDESCO, Antônio Cláudio; MORAES, Luiz Alberto Beraldo de; OLIVEIRA JUNIOR, Marcos de; COSTA, Beatriz Helena; PARVEEN, Rashida; RIBEIRO, Sidney José Lima; GONÇALVES, Rogéria Rocha.},title={Synergistic gas-bubbling and oxidative exfoliation for the reproducible synthesis of mesoporous g-C3N4 2D nanosheets with enhanced physicochemical properties},journal={ACS Omega},note={v. 11, n. 9, p. 15402-15416},year={2026}}