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

In the current research, NiAl2O4, NiAl1.98Bi0.02O4 and NiAl1.98Ce0.02O4 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 NiAl1.98Ce0.02O4 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% (NiAl1.98Ce0.02O4) and 91% (NiAl1.98Bi0.02O4) was noticed against MO degradation. Doping of cerium and bismuth in nickel aluminate enhanced the photocatalytic activity against the selected coloured organic pollutants. [Display omitted] •Bismuth and Cerium doped nickel aluminate was synthesized by sol-gel method.•The absorbance red shifted due to doping of bismuth and cerium in nickel aluminate.•Degradation of three pollutants MB, MO and RhB were studied.•94% of MO was degraded using cerium doped nickel aluminate.