Adsorption and photo-Fenton catalytic degradation of organic dyes over crystalline LaFeO3-doped porous silica

Thi To Nga Phan; Aleksandar N Nikoloski; Parisa Arabzadeh Bahri; Dan Li

doi:10.1039/c8ra07073c

Adsorption and photo-Fenton catalytic degradation of organic dyes over crystalline LaFeO₃-doped porous silica

RSC Adv. 2018 Oct 24;8(63):36181-36190. doi: 10.1039/c8ra07073c. eCollection 2018 Oct 22.

Authors

Thi To Nga Phan¹, Aleksandar N Nikoloski¹, Parisa Arabzadeh Bahri¹, Dan Li¹

Affiliation

¹ Chemical and Metallurgical Engineering and Chemistry, School of Engineering and Information Technology, Murdoch University Western Australia Australia L.Li@murdoch.edu.au +61 8 9360 2569.

Abstract

LaFeO₃ (LFO)-doped mesoporous silica (HPS) (HPS-xLFO with theoretical LFO/silica molar ratio x = 0.075, 0.15, 0.3) was successfully prepared via impregnation of metal ions into the porous silica HPS-0LFO support and subsequent calcination. The characterization studies suggest that increasing the doping of LFO, which exhibited a particle size of ∼10-15 nm, in the silica support led to a reduction in surface area and bandgap of the resulting catalyst. The use of HPS-0.15LFO yielded a superior removal rate (98.9%) of Rhodamine B (RhB), thanks to the effective dark adsorption and visible light-induced photo-Fenton degradation, both of which were greater than those of pure LFO crystals. This enhancement could be explained by the unique properties of the mesoporous silica support. In particular, the wide-opening mesopores created a large surface area to dope LFO as active sites and minimize diffusion of RhB into pores during the photo-Fenton reaction. The photo-Fenton catalytic degradation of RhB could reach 98.6% within 90 min exposure to visible light irradiation under optimized conditions: RhB concentration = 10 mg L^-1, catalyst dosage = 1 g L^-1, pH = 6 and H₂O₂ = 15 mM. Moreover, the recycle and reuse test proved the good stability and repetitive use of HPS-0.15LFO for high performance RhB removal.