Activity enhancement pathways in LaFeO3@TiO2 heterojunction photocatalysts for visible and solar light driven degradation of myclobutanil pesticide in water

Abstract

TiO2@LaFeO3 heterojunction composites with a core-shell porous structure and LaFeO3 contents in the 2.5-25 wt.% range have been synthesized via consecutive sol-gel syntheses and tested for the photocatalytic oxidation of the myclobutanil pesticide in water under solar light and pure visible light.Whatever the light spectrum, the kinetic rate constants for both myclobutanil degradation and TOC conversion exhibited a volcano-like profile with increasing the narrow band-gap (2.1 eV) LaFeO3 content, the optimum composite strongly overperforming both single phases, with full myclobutanil mineralization achieved in 240 min in the best case. The light spectrum influenced the optimum LaFeO3 content in the composite, being observed at 5 wt.% and 12.5 wt.% under solar and visible light, respectively. This has been attributed to the existence of different light-mediated reaction mechanisms. The optimum LaFeO3/TiO2 composite photocatalyst was active and stable after several runs under solar light with leached iron concentration below 0.1 mg/L in solution.

Substantial enhancement in the photocatalytic degradation of organic/inorganic pollutants in water and photoelectrochemical activity using TiO2@Ag@LaFeO3 core–shell nanorods

“…The TiO 2 surface shows near band-edge emission (NBE) and surface imperfections. 24,25 The NBE is attributed to direct band gap transition from the conduction band to the valence band. The TiO 2 NRs show multiple emissions at 361, 377, 437, and 519 nm.…”

Heterogeneous Photo‐Fenton Catalytic Oxidation of Ciprofloxacin Using LaFeO3/Diatomite Composite Photocatalysts under Visible Light

“…Extrapolation of the plots to the potential axis resulted in flat-band potentials of À 0.875 eV (vs. Ag/AgCl) for LaFeO 3 /Diatomite. [30] According to the slope of Mott-Schottky equation, [31] the carrier density (N D ) at 250 Hz, 500 Hz, 1000 Hz and 1500 Hz can be determined as 7.83 × 10 24 cm À 3 , 7.69 × 10 24 cm À 3 , 7.28 × 10 24 cm À 3 , 6.89 × 10 24 cm À 3 , respectively.…”

Solar photo-oxidation of recalcitrant industrial wastewater: a review

“…When the catalysts are immobilized, photon transmission may not contact all targets for photonic excitation, making the operation more challenging. As a result, titanium dioxide catalysts in the slurry form are frequently used (Cerrato et al 2019;Garcia-Muñoz et al 2020a).…”