Synthesis, characterization, and visible-light-driven photocatalytic performance of W-SBA15

Abstract

a b s t r a c tA series of tungsten-containing mesoporous SBA15 with different tungsten contents were prepared through a direct co-condensation sol-gel method and then analyzed by various techniques. XRD patterns revealed that the original mesoporous morphology was maintained after introducing tungsten species and forms of tungsten species were changed from incorporated tungsten to isolated tungsten species or low oligomeric tungsten oxide species, and finally to crystalline WO 3 with the increase of tungsten precursor content, which were also proven by HRTEM images, UV-Vis DRS, and FT-IR spectra. The W-SBA15 samples exhibited satisfactory photocatalytic performance toward degradation of dye Rhodamine B (RhB) and 2,4-dichlorophenol (2,4-DCP). In particular, the best candidate, sample 10%W-SBA15 showed an apparent reaction rate constant for RhB that was nearly 10 times as high as that of bulk WO 3 . The enhancement of photocatalytic capability was attributed to the mesoporous morphology with enlarged surface areas, negatively charged surface, and favorable tungsten forms such as incorporated tungsten, isolated tungsten or low oligomeric tungsten oxide species. In addition, active radicals trapping experiments and DMPO spin-trapping ESR spectra indicated that photogenerated holes were major oxidative species during photocatalysis.

Application of ionic mesoporous silica in selective recovery of tungstate ions through column adsorption and subsequent photocatalytic degradation of an organic dye

“…This reveals the dispersion and plausible aggregation of WO 4 2− tetrahedral species upon the ionic framework of IMOS. 32 EDS spectra of IMOS nanoparticles obtained before and after the recovery process illustrate the emergence of the ‘W’ peak at the cost of the ‘Cl’ peak, which exhibits the mechanism of anion-exchange (Fig. 2a and b).…”

Apple-like Zinc-Oxide Mesocrystals as Robust and Versatile Photocatalysts for Efficient Degradation of Eight Different Organic Dyes

“… 14 − 16 Photocatalysis has thus attracted increasing attention as a promising technique for the degradation of organic dyes in contaminated water due to its high efficiency and low cost. 17 − 20 Metal semiconductor materials have advantages such as low energy consumption and nontoxicity, and they have recently been investigated as potential photocatalysts to remove dye pollutants. 21 − 23 …”

“…A variety of chemical and physical methods such as chemical precipitation and adsorption have been established for the treatment of organic dyes. − However, these conventional approaches often suffered from severe drawbacks such as incomplete degradation, secondary pollution, and high operational cost. − Photocatalysis has thus attracted increasing attention as a promising technique for the degradation of organic dyes in contaminated water due to its high efficiency and low cost. − Metal semiconductor materials have advantages such as low energy consumption and nontoxicity, and they have recently been investigated as potential photocatalysts to remove dye pollutants. − …”

Palladium nanoparticles decorated into a biguanidine modified-KIT-5 mesoporous structure: a recoverable nanocatalyst for ultrasound-assisted Suzuki–Miyaura cross-coupling

“…Given the reasons mentioned, ultrasound-assisted methods are a green methodology for the preparation of various organic and inorganic compounds under mild reaction conditions, leading to high reaction yields and lower levels of pollution. 26 In continuation of our endeavors to support sustainable development using nanocatalysis, 27 we herein introduce (Scheme 1) an ultrasound-assisted method as a simple green synthetic method using a new KIT-5-biguanidine-Pd(0) catalyst, and we applied it to the Suzuki-Miyaura cross-coupling reaction. The prepared nanocatalyst was used for the Suzuki-Miyaura cross-coupling reaction of phenylboronic acid and various aryl halides (X ¼ Cl, Br, I) and the reactions were successfully carried out in EtOH/H 2 O as the reaction solvent at ambient temperature.…”

“…Given the reasons mentioned, ultrasound-assisted methods are a green methodology for the preparation of various organic and inorganic compounds under mild reaction conditions, leading to high reaction yields and lower levels of pollution. 26 …”