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

Abstract

The mesoporous N-doped TiO 2 /Si-O-C-N ceramic nanocomposites has been revealed to be a potential candidate Mesoporous towards visible light photocatalytic degradation of organic dyes. The polymer-derived ceramic route was im-Nanocomposite plemented to prepare uniformly distributed in-situ crystallized N-doped TiO 2 nanocrystals in a mesoporous Photocatalysis amorphous siliconoxycarbonitride matrix. This chemical approach assisted by the hard template pathway re-Adsorption sulted in a high surface area (186 m 2 /g) nanocomposite exhibiting predominantly mesoporous structure with an Heterojunction 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 TiO 2 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.

Low temperaturein situformation of cobalt in silicon nitride toward functional nitride nanocomposites

“…1 In this category of energy-focused materials, advanced ceramics appear to be high value-added products with performances that are tailored via their rational and elaborate designs. [2][3][4][5][6] Ceramic processing methods based on molecular engineering and precursor chemistry are well appropriate approaches to design such materials that can reach performances far beyond those developed by more conventional synthesis routes. [7][8][9][10] A very convenient precursor route is the polymer derived ceramics and VN/Si N 34 compounds.…”

Single source precursor‐derived SiOC/TiOxCy as an anode component for Li‐ion batteries

“…These peaks prove that the Ti-O bonds are in different oxidation states (Ti 4+ / Ti 3+ / Ti 2+ ). 44,53,54 Although the AST12 sample deconvoluted spectrum of Ti 2p3/2 (Figure 3R) contained three similar peaks with the broadened area, and a peak shift was observed from 456.1 eV to 454.8 eV and 458.9 eV to 459.4 eV. The increase in peak intensity could be attributed to the presence of Ti-C bonds.…”

“…The corresponding deconvoluted data of all the samples are presented in Table 2. 44,[47][48][49][50][51] The high carbon content in the PS9 sample (Figure 3B) clearly indicated additional SiCO 3 bonds 47. Furthermore, the C 1s peak (Figure 3C) suggests that the C-Si bonds had a higher intensity peak than C-C bonds.…”

“…19,44 However, the PST9 and AST12 samples showed no evidence of titania (TiO 2 ) phase development or crystallization. In undoped TiO 2 , the transformation of anatase to rutile phase of TiO 2 occurs completely above 800 • C. 45 Under ambient conditions, the stable anatase phase of TiO 2 was seen in TiO 2 /SiOC composites until 1200 • C. 44 However, during pyrolysis and annealing in an argon atmosphere, oxygen was insufficient for the crystallization of the anatase phase or the rutile phase of TiO 2 in the SiOC matrix, resulting in amorphous phase SiOC/TiO x C y ceramics. Further, Rietveld refinement was performed on an X-ray diffractogram obtained at scan rate of 12 s/step (Figure S1) using MAUD software.…”

From design to characterization of zirconium nitride/silicon nitride nanocomposites

“…In this work, we have exploited the advantage of producing TMN/ Si3N4 compounds [14,15,[21][22][23] by the PDC route [24][25][26][27][28][29][30][31][32][33][34][35][36][37] to design ZrN/Si3N4 nanocomposites where their structure can be well controlled from the precursor level. Our approach involves first the synthesis of zirconium (Zr)-modified polysilazanes from liquid polysilazanes as Si3N4 precursors, i.e., polymethylsilazane (PMSZ) and poly(vinyl-methyl-comethyl)silazane (PVMSZ), which are known to deliver Si-C-N ceramics [22,38,39].…”