Ultrasound assisted synthesis of iron doped TiO2 catalyst

Abstract

The present work deals with synthesis of Fe (III) doped TiO catalyst using the ultrasound assisted approach and conventional sol-gel approach with an objective of establishing the process intensification benefits. Effect of operating parameters such as Fe doping, type of solvent, solvent to precursor ratio and initial temperature has been investigated to get the best catalyst with minimum particle size. Comparison of the catalysts obtained using the conventional and ultrasound assisted approach under the optimized conditions has been performed using the characterization techniques like DLS, XRD, BET, SEM, EDS, TEM, FTIR and UV-Vis band gap analysis. It was established that catalyst synthesized by ultrasound assisted approach under optimized conditions of 0.4mol% doping, irradiation time of 60min, propan-2-ol as the solvent with the solvent to precursor ratio as 10 and initial temperature of 30°C was the best one with minimum particle size as 99nm and surface area as 49.41m/g. SEM analysis, XRD analysis as well as the TEM analysis also confirmed the superiority of the catalyst obtained using ultrasound assisted approach as compared to the conventional approach. EDS analysis also confirmed the presence of 4.05mol% of Fe element in the sample of 0.4mol% iron doped TiO. UV-Vis band gap results showed the reduction in band gap from 3.2eV to 2.9eV. Photocatalytic experiments performed to check the activity also confirmed that ultrasonically synthesized Fe doped TiO catalyst resulted in a higher degradation of Acid Blue 80 as 38% while the conventionally synthesized catalyst resulted in a degradation of 31.1%. Overall, the work has clearly established importance of ultrasound in giving better catalyst characteristics as well as activity for degradation of the Acid Blue 80 dye.

The Sonophotocatalytic Degradation of Pharmaceuticals in Water by MnOx-TiO2 Systems with Tuned Band-Gaps

“…The Mie theory applies to Mn-doped TiO 2 particles, as all the mean particle sizes are between 4 and 13 µm and the particle's median sizes are between 4 and 11 µm for the samples synthesized with ultrasound (Table 1). It is well known that ultrasound cavitation in comparison to the conventional sol-gel process reduces the particle size and the size of agglomerates on the support [32,33]. However, the smaller the particle, the higher the risk of sintering during calcination [31,56].…”

“…Increasing the amount of solvent results in a homogenous reaction mixture, and therefore produces particles with higher surface areas and pore volumes [33]. However, in the absence of alcohol, particles have an irregular shape.…”

“…The efforts of researchers in the field of photocatalysis aim mainly at extending the band-gap to the visible light region of the solar spectrum (λ > 400 nm). To cope with the lengthy catalyst preparation steps and to improve the mixing between active phase and dopant(s), spray drying and ultrasound is an approach that has been recently adopted by the authors of this paper [29][30][31][32][33][34]. The shape and size of catalysts vary with the operating parameters, including the ultrasound irradiation time, temperature, power density, the ultrasonic source (bath-type and horn-type), magnetic stirring, and reactor shape and size [24,[35][36][37].…”

Energy‐Efficient 2‐Ethylhexyl Acetate Synthesis with a Nano‐Sn‐Hydroxyapatite Photocatalyst

“…The application of ultrasound‐wave energy (UWE) after STE in STUWEPC preparation generated shock waves that rendered faster growth and collapse of cavitation bubbles within a nanosecond , which resulted in strong vibrational energy that finally enabled smaller nucleation of Sn nanoparticles with more uniform dispersion . This also imparted to further augmentation in BSA and catalyst pore volume.…”

“…This was because STE constituting the near-infrared fraction (700-1100 nm) facilitated exorbitant molecular excitation through stretching and bending vibration that caused faster atomic rearrangements in the crystalline structure, resulting in rapid ionic substitution with a remarkable improvement in the surface property of STEPC 0.2 [17]. The application of ultrasound-wave energy (UWE) after STE in STUWEPC preparation generated shock waves that rendered faster growth and collapse of cavitation bubbles within a nanosecond [18], which resulted in strong vibrational energy that finally enabled smaller nucleation of Sn nanoparticles with more uniform dispersion [19]. This also imparted to further augmentation in BSA and catalyst pore volume.…”