Microwave–ultrasound assisted synthesis of β-FeOOH and its catalytic property in a photo-Fenton-like process

Abstract

In this study, nanoparticles of single-phase akaganeite (β-FeOOH) were synthesized by an ultrasound-microwave assisted method. The synthesis parameters were optimized by means of response surface methodology. X-ray diffractions (XRD), Fourier transform infrared spectrum (FTIR), UV-vis diffused reflection spectra (UV-vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and specific surface area were used to characterize the as-prepared samples. The catalytic activity of the prepared β-FeOOH was evaluated in a heterogeneous photo-Fenton-like process using methyl orange as target pollutant. It is found that the reaction temperature and interaction between microwave and ultrasound have a significant influence on the catalytic properties of the prepared β-FeOOH samples. The β-FeOOH prepared at microwave power of 400 W, ultrasound power of 200 W, reaction temperature of 70°C and reaction time of 3 h, exhibited considerable catalytic activity in weak alkaline solution and under visible light irradiation, which would be of great promise for the industrial application of this catalyst to oxidize organic pollutants for wastewater treatment.

An Ultrasonication-Assisted Cobalt Hydroxide Composite with Enhanced Electrocatalytic Activity toward Oxygen Evolution Reaction

“…Ultrasonication can bring instantaneous generation, and the growth and collapse of micrometer-sized bubbles in liquid medium, which is helpful for the synthesis of nanostructured materials. Recently, the use of ultrasonication in chemistry has grown significantly [ 29 , 30 , 31 ]. In the present work, we prepared cobalt hydroxide [Co(OH) 2 ] by parallel flow precipitation on carbon black with the assistance of ultrasonication.…”

Combined Microwaves/Ultrasound, a Hybrid Technology

“…Goethite and akageneite are ferric oxyhydroxides (α-and β-FeOOH) that are employed in the degradation of organic compounds with hydrogen peroxide under relatively weak UV irradiation. Z. Xu et al have published a paper on the preparation of α-FeOOH via the SMUI of a FeCl3•6H2O solution in urea and deionised water [52] A high-intensity ultrasonic probe (from Xinzhi Co., China, JY92-2D) with a 10 mm diameter titanium horn of 20 kHz in a pulsed mode was used in this process. It had a duty cycle of 1 s and was directly immersed 1 cm into the solution.…”

Identifying Iron-Bearing Nanoparticle Precursor for Thermal Transformation into the Highly Active Hematite Photo-Fenton Catalyst

“…Different materials for heterogeneous photo-Fenton catalysts have been reported, such as α-,β-,γ-Fe 2 O 3 [4][5][6][7][8], Fe 3 O 4 [9], FeO [9], α-,β-FeOOH [10,11], LaFeO 3 [12], BiFeO 3 [13], Fe 2 (MeO 4 ) 3 [3] and spinel ferrites MFe 2 O 4 (where M is divalent metal cation) [14,15]. Additionally, the catalytic activity towards photo-Fenton reaction can be enhanced by synthesizing heterostructures with metals [2], metal oxides [16] and graphitic C 3 N 4 [17].…”