Synthesis of cerium and bismuth doped nickel aluminate for the photodegradation of methylene blue, methyl orange and rhodamine B dyes

R Chellammal Gayathri; V Elakkiya; S Sumathi

doi:10.1016/j.chemosphere.2022.135056

Synthesis of cerium and bismuth doped nickel aluminate for the photodegradation of methylene blue, methyl orange and rhodamine B dyes

Chemosphere. 2022 Sep;303(Pt 2):135056. doi: 10.1016/j.chemosphere.2022.135056. Epub 2022 May 23.

Authors

R Chellammal Gayathri¹, V Elakkiya¹, S Sumathi²

Affiliations

¹ Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632014, India.
² Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632014, India. Electronic address: sumathishanmugam2003@gmail.com.

PMID: 35618053
DOI: 10.1016/j.chemosphere.2022.135056

Abstract

In the current research, NiAl₂O₄, NiAl_1.98Bi_0.02O₄ and NiAl_1.98Ce_0.02O₄ are fabricated by the sol-gel method. Doping of larger ions (Ce³⁺ and Bi³⁺) into smaller aluminium ion lattice increased the lattice constant from 8.0091 Å to 8.9732 Å and 8.0272 Å respectively. XPS spectra of NiAl_1.98Ce_0.02O₄ confirmed the existence of Ce ion in Ce³⁺ and Ce⁴⁺. Spherical shaped particles with visible pores are noticed in the Transmission Electron Microscopy (TEM). The bandgap of the tailored materials has decreased to 2.25 eV and 2.98 eV and increased the catalytic efficiency due to the decrease in electron-hole pair recombination rate. The photocatalytic efficiency of the materials was tested against methylene blue (MB), methyl orange (MO) and rhodamine B (RhB) dyes. In the case of MB degradation, the efficiency of nickel aluminate (0.5 mg/mL) was 54% under UV light irradiation after 60 min, which was increased to 94% and 89% through cerium doped and bismuth doped nickel aluminate catalyst respectively. A drastic increase from 31% to 94% (NiAl_1.98Ce_0.02O₄) and 91% (NiAl_1.98Bi_0.02O₄) was noticed against MO degradation. Doping of cerium and bismuth in nickel aluminate enhanced the photocatalytic activity against the selected coloured organic pollutants.

Keywords: Bismuth; Cerium; Methyl orange; Methylene blue; Nickel aluminate; Photocatalysis; Rhodamine B.