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

In the current research, NiAlO, NiAlBiO and NiAlCeO are fabricated by the sol-gel method. Doping of larger ions (Ce and Bi) 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 NiAlCeO confirmed the existence of Ce ion in Ce and Ce. 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% (NiAlCeO) and 91% (NiAlBiO) was noticed against MO degradation. Doping of cerium and bismuth in nickel aluminate enhanced the photocatalytic activity against the selected coloured organic pollutants.