Light‐Assisted Photocatalytic Degradation of Congo Red Using Biogenically Fabricated Nickel Oxide Nanoparticles Synthesized From Kalanchoe pinnata Leaf Extract

ABSTRACT

One of the significant challenges in managing organic pollutants is to develop stable, highly effective metal oxide‐based photocatalysts. This study shows the green synthesis of Nickel oxide nanoparticles (NiO NPs) using Kalanchoe pinnata (KP) leaves extract. The synthesized NiO NPs were characterized using various spectroscopy and analytical techniques such as XRD, FTIR, ultraviolet–visible spectrophotometer, FESEM, HRTEM, and BET. The crystallite size was found to be 4.69 nm for NiO NPs (control) and 3.63 nm for Ni (KP) NPs. The d‐spacing was calculated and found to be 0.245 nm for NiO NPs (control) and 0.213 nm for NiO (KP) NPs. The most effective NiO(KP) NPs synthesized using Kalanchoe pinnata leaves exhibited a light‐assisted degradation efficiency of ∼ 94.46% with a kinetic rate constant of 0.06 min ⁻¹ . The UV‐vis absorption spectra were checked, and it was found to be 299 nm for the NiO (KP) NPs, and for the light‐assisted degradation of Congo red at 498 nm. The E _g of NiO(KP) NPs was 2.97 eV. Thus, the current findings illustrate the potential of NiO(KP) NPs as a good photocatalyst for dye pollutants.