A novel Sm doped Cr2O3 sesquioxide-decorated MWCNTs heterostructured Fenton-like with sonophotocatalytic activities under visible light irradiation

Gh Eshaq; Amer M; Moonis Ali Khan; Zeid A Alothman; Mika Sillanpää

doi:10.1016/j.jhazmat.2021.127812

A novel Sm doped Cr₂O₃ sesquioxide-decorated MWCNTs heterostructured Fenton-like with sonophotocatalytic activities under visible light irradiation

J Hazard Mater. 2022 Mar 15:426:127812. doi: 10.1016/j.jhazmat.2021.127812. Epub 2021 Nov 21.

Authors

Gh Eshaq¹, Amer M², Moonis Ali Khan³, Zeid A Alothman³, Mika Sillanpää⁴

Affiliations

¹ Department of Separation Science, School of Engineering Science, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland; Petrochemicals department, Egyptian Petroleum Research Institute, Nasr City, Cairo 11727, Egypt.
² Division of Cardiac Surgery, Heart Centre Siegburg-Wuppertal, University Witten, Herdecke, Germany.
³ Chemistry Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
⁴ Chemistry Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; Faculty of Science and Technology, School of Applied Physics, University Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; School of Chemistry, Shoolini University, Solan, Himachal Pradesh, 173229, India; Department of Biological and Chemical Engineering, Aarhus University, Nørrebrogade 44, 8000 Aarhus C, Denmark.

PMID: 34844808
DOI: 10.1016/j.jhazmat.2021.127812

Abstract

Novel Sm doped Cr₂O₃ decorated MWCNTs nanocomposite photocatalyst was successfully prepared by a facile hydrothermal method for metoprolol (MET) degradation. A heterogeneous photo -Fenton like system was formed with the addition of H₂O₂ for ultrasonic irradiation (US), visible light irradiation (Vis) and dual irradiation (US/Vis) systems. The intrinsic characteristics of Sm doped Cr₂O₃ decorated MWCNTs nanocomposite was comprehensively performed using state-of-art characterization tools. Optical studies confirmed that Sm doping shifted the absorbance of Cr₂O₃ towards the visible-light region, further enhanced by MWCNTs incorporation. In this study, degradation of metoprolol (MET) was investigated in the presence of Cr₂O₃ nanoparticles, Sm doped Cr₂O₃ and Sm doped Cr₂O₃ decorated MWCNTs nanocomposites using sonocatalysis and photocatalysis and simultaneously. Several different experimental parameters, including irradiation time, H₂O₂ concentration, catalyst amount, initial concentration, and pH value, were optimized. The remarkably enhanced sonophotocatalytic activity of Sm doped Cr₂O₃ decorated MWCNTs could be attributed to the more formation of reactive radicals and the excellent electronical property of Sm doping and MWCNTs. The rate constant of degradation using sonophotocatalytic system was even higher than the sum of rates of individual systems due to its synergistic performance based on the kinetic data. A plausible mechanism for the degradation of MET over Sm-Cr₂O₃/MWCNTs is also demonstrated by using active species scavenger studies and EPR spectroscopy. Our findings imply that (^•OH), (h⁺) and (^•O₂^-) were the reactive species responsible for the degradation of MET based on the special three-way Fenton-like mechanism and the dissociation of H₂O₂. The durability and stability of the nanocomposite were also performed, and the obtained results revealed that the catalysts can endure the harsh sonophotocatalytic conditions even after fifth cycles. Mineralization experiments using the optimized parameters were evaluated as well. The kinetics and the reaction mechanism with the possible reasons for the synergistic effect were presented. Identification of degraded intermediates also investigated.

Keywords: Heterogeneous photocatalyst; Rare earth; Sm doped; Synergistic effect; β-blockers.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Catalysis
Hydrogen Peroxide
Light
Nanocomposites*
Nanoparticles*

Substances

Hydrogen Peroxide