Preparation of mesoporous TiO2–SiO2 by ultrasonic impregnation method and effect of its calcination temperature on photocatalytic activity

Abstract

a b s t r ac tThis article presents a novel procedure to synthesis mesoporous TiO 2 -SiO 2 structure via ultrasonic impregnation method. Mesoporous silica SBA-15 as a host structure was first prepared. Then, the prepared host structure was mixed with a homogenized solution of TiO 2 precursor under ultrasonic condition at 40°C. To understand the chemical composition and structural properties of the synthesized powder, several characterization techniques such as powder X-ray diffraction, small-angle X-ray scattering, nitrogen adsorption, X-ray photoelectron spectroscopy, transmission electron microscopy, field-emission scanning electron microscopy and energy dispersive X-ray were employed. Photocatalytic activity of the calcined materials at various temperatures (400°C, 600°C, and 800°C) was evaluated by degradation of methylene blue solution under UV light. The anatase crystals were the only detected phase until 800°C due to formation of Ti-O-Si bonds. Photo-degradation results revealed that all of synthesized samples possess much more photocatalytic activity than commercial TiO 2 . In addition, a higher photocatalytic efficiency was achieved at higher calcination temperature owing to more degree of crystallinity.

Green Biosynthesis of Silver Nanoparticles Using Eriobotrya japonica (Thunb.) Leaf Extract for Reductive Catalysis

“…Mirtaheri et al (2017) synthesized mesoporous tungsten oxide using a template-assisted sol-gel method for the photocatalytic degradation of Rhodamine B [4]. Haghighatzadeh et al (2017) synthesized mesoporous TiO 2 -SiO 2 via an ultrasonic impregnation method and the anatase crystals synthesized under 800 °C with a higher photocatalytic efficiency for methylene blue degradation [5]. By comparison, green biosynthetic methods are much safer, greener, and eco-friendlier approaches [6].…”

Theranostic Nanoparticles and Their Spectrum in Cancer

“…Mesoporous TiO 2 -SiO 2 were synthesized by Haghighatzadeh et al using an ultrasonic impregnation method. In addition, under 800°, they synthesized the anatase crystals with higher photocatalytic efficiency for degradation of methylene blue [29]. Deshmukh et al synthesized various nanoparticles using plant extracts in order to evaluate their antibacterial and antioxidant activity for targeted applications [30].…”

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“…The toxic nitrophenols (especially 4-NP) are largely responsible as the main environmental pollutants , and must be converted into harmless aminophenols (especially 4-AP) that are prospective intermediates and precursors for pharmaceuticals, synthetic resins, pesticides, and dyes ideally via a reductive protocol. ,,− Another hazardous heavy metal in wastewater is [Cr­(VI)], produced during some large-scale industrial processes. Trivalent chromium [Cr­(III)], in contrast, has 100-fold less toxicity and can be efficiently eliminated via the formation of insoluble hydroxides in water under controlled conditions. ,− Consequently, it is obligatory to develop efficient, ecofriendly, and sustainable methods for the treatment of nitro compounds, organic dyes, and heavy metals, thus addressing both the energy demand and environmental issues; the assembly of nanocomposites and modified nanoparticles does inspire newer strategies for the degradation of pollutants and environmental remediation. − …”