Tailoring photocatalytic performance: Lanthanum doping in nickel oxide for efficient degradation of some industrial cationic dyes in visible light radiation

Abstract

Metal oxide nanoparticles have emerged as an important component in heterogeneous photocatalysis, which uses light-induced reactions on the surface of a catalyst to drive chemical transformations. The improved photocatalytic activity of lanthanum-doped metal oxide nanoparticles has been the subject of research due to their special qualities, which include enhanced photocatalytic performance, stability and absorption of visible light. This study involves co-precipitation approach to synthesize nickel oxide nanoparticles and nickel oxide nanoparticles doped with lanthanum. The nanoparticles were determined using UV-Visible absorption spectrophotometry, X-ray diffraction spectroscopy, Energy-disperse spectroscopy, Photoluminescence spectroscopy and Field emission scanning electron microscopy. For the photodegradation of malachite green and rhodamine B dyes, synthesized nanoparticles were employed as photocatalysts. Compared to pure NiO, the photochemical activity of 4 % Lanthanum-doped NiO was higher. The degrading efficiency of 4 % La-doped NiO is 89 % effective towards rhodamine B and 87 % for malachite green. In addition, entrapment was done to identify primary active species responsible for photocatalytic activity. The present study likely provides new insights and novelty into the photocatalytic mechanisms at play, including how lanthanum doping affects the generation and dynamics of reactive oxygen species (ROS) like hydroxyl radicals and superoxide anions, which are responsible for the breakdown of dye molecules.