Enhanced degradation of Congo-red dye by Cr3+ doped α-Fe2O3 nano-particles under sunlight and industrial wastewater treatment

Preety Yadav; Neeraj Dhariwal; Manju Kumari; Vinod Kumar; O P Thakur

doi:10.1016/j.chemosphere.2023.140208

Enhanced degradation of Congo-red dye by Cr³⁺ doped α-Fe₂O₃ nano-particles under sunlight and industrial wastewater treatment

Chemosphere. 2023 Dec:343:140208. doi: 10.1016/j.chemosphere.2023.140208. Epub 2023 Sep 20.

Authors

Preety Yadav¹, Neeraj Dhariwal¹, Manju Kumari¹, Vinod Kumar², O P Thakur¹

Affiliations

¹ Material Analysis and Research Laboratory, Department of Physics, Netaji Subhas University of Technology (NSUT), Dwarka, New Delhi, 110078, India.
² Material Analysis and Research Laboratory, Department of Physics, Netaji Subhas University of Technology (NSUT), Dwarka, New Delhi, 110078, India. Electronic address: vinod@nsut.ac.in.

PMID: 37739127
DOI: 10.1016/j.chemosphere.2023.140208

Abstract

Considering the increasing amount of water pollution, nanocomposite advances for the effective elimination of hazardous pollutants are still needed. α-Fe₂O₃, Cr_0·5Fe_1·5O₃ and CrFeO₃ nanoparticles were synthesized via an eco-friendly material synthesis i. e hydrothermal route without using any precipitating agent and were studied to remove congo-red dye using photocatalytic properties. X-ray diffraction (XRD), Transmission electron microscopy (TEM), Field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FESEM), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS) characterizations have been performed to know about the material structure and properties of synthesized samples. High efficiency (95.2%) of degradation was achieved under sunlight using a very low amount of CrFeO₃ catalyst (0.2 g/L) at a 6-pH level of dye and was confirmed using UV spectroscopy, TOC (84%), LC-HRMS. Also, the potential to degrade the CR dye was concluded from the high rate of BOD₅/COD. The results showed a significant enhancement in the degradation of α-Fe₂O₃ from 52.3% to 95.2% in a short duration of 15 min by introducing chromium as a dopant. The doping of chromium influenced the major factors responsible for the photocatalytic activity such as the increase in range of absorbance, increased e^--h⁺ pair separation, improvement in the charge transfer process and active site formation which significantly enhanced the process of degradation. We found that the Cr-doped α-Fe₂O₃ nanomaterial could effectively remove dyes, such as congo-red, from industrial water-waste.

Keywords: Photocatalyst; Reusability; Water-waste; α-Fe(2)O(3).