Disordered mesoporous polymer derived N-doped TiO2/Si-O-C-N nanocomposites with nanoscaled heterojunctions towards enhanced adsorption and harnessing of visible light

• Published in: Applied surface science Vol. 508; pp. 144953 - 144961
• Main Authors: Awin, Eranezhuth Wasan, Lale, Abhijeet, Hari Kumar, K.C., Bernard, Samuel, Kumar, Ravi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2020; Elsevier
• Subjects: Adsorption; Chemical Sciences; Engineering Sciences; Heterojunction; Material chemistry; Materials; Mesoporous; Nanocomposite; Photocatalysis; Nanocomposite; Adsorption; Mesoporous; Photocatalysis; Heterojunction
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2019.144953

[Display omitted] •In-situ crystallization of N-doped TiO2 nanocrystals in amorphous Si-O-C-N matrix.•Mesoporous nanocomposite exhibited ultra-high adsorption capacity.•Nitrogen atoms in the TiO2 lattice facilitated visible light photocatalysis.•Synergistic effect of nanoscaled heterojunctions and radicals enhanced catalysis.•Photodegradation rate constant was found to be 8.3 × 10−3 min−1. The mesoporous N-doped TiO2/Si-O-C-N ceramic nanocomposites has been revealed to be a potential candidate towards visible light photocatalytic degradation of organic dyes. The polymer-derived ceramic route was implemented to prepare uniformly distributed in-situ crystallized N-doped TiO2 nanocrystals in a mesoporous amorphous siliconoxycarbonitride matrix. This chemical approach assisted by the hard template pathway resulted in a high surface area (186 m2/g) nanocomposite exhibiting predominantly mesoporous structure with an average pore size of 11 nm. The two-step process involved pyrolysis of the polyhydridomethyilsiloxane impregnated in CMK3 (hard template) under argon generating SiOC-C composites and functionalizing it with titanium n-tetrabutoxide to be pyrolyzed under ammonia to form the titled nanocomposite. Interestingly, pyrolysis in a reactive ammonia atmosphere resulted in the incorporation of nitrogen in the titania lattice while decomposing the template. The Si-O-C-N support on which N-doped TiO2 exhibited superior adsorption of organic dye molecules and photocatalytically active in the visible wavelength. The nanoscaled heterojunctions reduced the recombination rate and the presence of superoxide anions/hydroxyl radicals was found to be responsible for the dye degradation.