New Porous High Surface Area, TiO₂ Anatase/SAPO‐35 Mild Brønsted Acidic Nanocomposite: Synthesis, Characterization and Studies on it's Enhanced Photocatalytic Activity.

Abstract

type microporous silico alumino phosphate SAPO-35 are synthesized by using hydrothermal method. TiO 2 /SAPO-35 nanocomposites were prepared by solgel method with different weight ratios. The synthesized materials were characterized by various analytical techniques such as PXRD, SEM/EDAX, TG/DTA, BET-Surface area, FT-IR, UV-Vis, XPS, MAS-NMR and photocatalytic study. From PXRD results it clearly evidenced that, the TiO 2 anatase peaks and SAPO-35 combined peaks are in the composite. The spherical shaped TiO 2 nanoparticles were found to be dispersed over the rhombohedral SAPO-35 particles, which was analysed by SEM. BET-surface area analysis revealed that, the calcined SAPO-35 has the surface area of 448 m 2 /g, was decreased to 222 m 2 /g for composite which is due to the presence of TiO 2 particles having surface area of 85 m 2 /g on the surface of SAPO-35. The oxidation state and co-ordination of various elements present in nanocomposite was composed by X-ray photoelectron spectroscopy. MAS-NMR analysis has shown that SAPO-35 has tetrahedral Al, P and Si oxides. Eventhough Al is unique Si and P are in two different environment namely one in S6R and another in D6R with double intensity. The photocatalytic performance of methylene blue degradation under sunlight radiation by the synthesized TiO 2 /SAPO-35 was analyzed. The TiO 2 /SAPO-35 composites degrade the methylene blue under sunlight irradiation in 25 minutes against 90 minuts for pure TiO 2 anatase. A plausible mechanism on photocatalytic activity is also proposed.

Investigation on the Promoter-Induced Rapid Non-Aqueous Media Synthesis of SAPO-35 and Methanol-to-Olefin Reaction

“…Figure represents the PXRD patterns of the SAPO and promoter samples, and it can be observed from Figure that the peaks at 2θ values of 10.9, 13.3, 17.3, 21.9, 26.6, and 32.3° correspond to Miller indices of (012), (110), (104), (024), (220), and (134) planes, respectively. As per the literature [JCPDS: 51–0052], it is confirmed that the synthesized SAPO-35 has a Levyne-type hexagonal crystalline structure. , Furthermore, the relative crystallinity of each sample was calculated using the most prominent peak in the corresponding PXRD pattern, which was observed at a 2θ value of 21.9° corresponding to the (024) plane. In order to calculate the relative crystallinity of the synthesized samples, the relative crystallinity of the standard sample prepared at 360 h was taken as 100%.…”

“…As per the literature [JCPDS: 51−0052], it is confirmed that the synthesized SAPO-35 has a Levyne-type hexagonal crystalline structure. 18,27 Furthermore, the relative crystallinity of each sample was calculated using the most prominent peak in the corresponding PXRD pattern, which was observed at a 2θ value of 21.9°corresponding to the (024) plane. In order to calculate the relative crystallinity of the synthesized samples, the relative crystallinity of the standard sample prepared at 360 h was taken as 100%.…”

“…SAPO-35 is a LEV (Levyne)-type topological framework microporous material with 0.36 × 0.48 nm ring opening pores, which are constructed by a single six-membered ring (S6R) and a double six-membered ring (D6R) with different T-sites in a 2:1 ratio, respectively. 18 It was synthesized using quinuclidine, cyclohexylamine, and hexamethyleneimine as the structure-directing agents (SDAs) for the crystallization of SAPO-35 at a 200 °C reaction temperature in aqueous media. 4,19 A very recent study revealed that SAPO-35 molecular sieves have been synthesized in a non-aqueous medium (ethylene glycol) using hexamethyleneimine as an SDA at 200 °C for a crystallization time of about 360 h. 20 This non-aqueous media samples showed a better crystalline nature as compared to the aqueous samples.…”

Facile Fabrication of Novel SrMoO4/g‐C3N4 Hybrid Composite for High‐Performance Photocatalytic Degradation of Dye Pollutant under Sunlight

“…As a result of well-matched, coinciding band-structures, photogenerated excitons effectively separated and migration towards the surface of SMO/G-CN-10 composite photocatalyst leads to the enhancement in photocatalytic activity. Plausible photocatalytic degradation mechanism of RhB dye pollutants under sunlight for SMO/G-CN-10 composite photocatalyst is represented by the following equations (5)(6)(7)(8)(9). SMO=G…”

“…These pollutants are hazardous to human and animal health even at their extreme trace concentration. [4][5][6] Hitherto, several methods such as photocatalytic degradation, membrane filtration, adsorption, flocculent precipitation, biological treatment, and so on were adopted for removal of water pollutants were adopted. [7][8][9][10][11] In comparison to these methods, the photocatalytic degradation method is widely preferred in the recent years, This is because, it is cost effective method as it employs the utilization of inexhaustible solar radiation as energy source and is found to be efficient, simple and convenient method.…”