Co+2, Ni+2 and Cu+2 incorporated Bi2O3 nano photocatalysts: Synthesis, DFT analysis of band gap modification, adsorption and photodegradation analysis of rhodamine B and Triclopyr

Anuradha Sharma; Shankar Sharma; Naveen Kumar; W A Diery; Elie A Moujaes; Muhammad Tahir; Pardeep Singh

doi:10.1016/j.envres.2023.116478

Co⁺², Ni⁺² and Cu⁺² incorporated Bi₂O₃ nano photocatalysts: Synthesis, DFT analysis of band gap modification, adsorption and photodegradation analysis of rhodamine B and Triclopyr

Environ Res. 2023 Sep 15:233:116478. doi: 10.1016/j.envres.2023.116478. Epub 2023 Jun 20.

Authors

Anuradha Sharma¹, Shankar Sharma¹, Naveen Kumar², W A Diery³, Elie A Moujaes⁴, Muhammad Tahir⁵, Pardeep Singh⁶

Affiliations

¹ Department of Chemistry, Maharshi Dayanand University, Rohtak, 124001, India.
² Department of Chemistry, Maharshi Dayanand University, Rohtak, 124001, India. Electronic address: naveenkumar.chem@mdurohtak.ac.in.
³ Physics Department, Faculty of Science, King AbdulAziz University, 21589, Jeddah, Saudi Arabia.
⁴ Physics Department, Federal University of Rondônia, Porto Velho, 76801-974, Brazil.
⁵ Chemical and Petroleum Engineering Department, UAE University, P.O. Box 15551, Al Ain, United Arab Emirates.
⁶ School of Advanced Chemical Sciences, Shoolini University, Solan, Himachal Pradesh, 173212, India.

PMID: 37348633
DOI: 10.1016/j.envres.2023.116478

Abstract

This study deals with the fabrication of metal ion (M = Co⁺², Ni⁺², and Cu⁺²) doped- Bi₂O₃ photocatalysts by solution combustion method. All the synthesized materials were characterized and analysed with the help of XRD, FESEM, EDX, HRTEM, UVDRS, Zeta potential, PL, and LCMS techniques for the structural, morphological, surface charge, optical and degradation pathways characteristics. Synthesized compounds were used for the decontamination (adsorption and degradation) of two organic pollutants namely Rhodamine B and Triclopyr. Adsorption aspects of the pollutants were studied in terms of different isotherm, kinetic and thermodynamic models. Adsorption phenomenon was best fitted with the Freundlich (R² = 0.992) and Langmuir isotherm (R² = 0.999) models along with pseudo second order model of kinetics for RhB and TC, respectively. Moreover, the thermodynamic parameters indicated exothermic and endothermic adsorption (ΔH ° (-7.19 kJ/mol) for RhB) and (ΔH ° (52.335 kJ/mol) for TC), respectively. Evaluated negative values of ΔG ° indicated spontaneous adsorption with most favourable at 298 K and 318 K for both the pollutants (RhB and TC) respectively. Modification with metal ions significantly improved the removal efficiency of pure Bi₂O₃ photocatalyst and followed the trend Co⁺²/Bi₂O₃ > Ni⁺²/Bi₂O₃ > Cu⁺²/Bi₂O₃ > Bi₂O₃. DFT calculations demonstrate that amongst the doped materials, only Co⁺²/Bi₂O₃ is characterized by an indirect band gap; which exhibited efficacious photocatalytic activity. Besides, the highest degradation efficiency was obtained in the case of Co⁺²/Bi₂O₃ (2 mol %); being 99.80% for RhB in 30 min and 98.50% for TC in 60 min, respectively. The doped nanostructures lead to higher absorption of visible light and more separation of light-induced charged carriers. Effect of pH of the reaction medium and role of reactive oxygen species was also examined. Finally, a probable mechanism of charge transfer and degradation of the pollutants was also presented.

Keywords: Bismuth oxide; Characterization; DFT; Degradation; Doped; Photocatalysis.

Publication types

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

MeSH terms

Adsorption
Photolysis
Thermodynamics
Water Pollutants, Chemical* / analysis

Substances

rhodamine B
triclopyr
Water Pollutants, Chemical