Sonochemical-assisted route for synthesis of spherical shaped holmium vanadate nanocatalyst for polluted waste water treatment

•Holmium vanadate oxide nanoceramics were provided by a sonochemical method.•Triethylenetetramine was taken as both capping and alkaline agent.•Various parameters such as amine concentration, reaction time and solvent type were optimize.•The photocatalytic efficiency of HoVO4 nanostructures were investigated. Solar photocatalytic process has been shown to be an energy effective and eco-friendly degradation of unwanted pollutants present in the industrial wastewater. The present study introduces the preparation and characterization of novel holmium vanadate (HoVO4) nanostructures that fully used in the photodegradation efficiency of anionic and cationic organic pollutants. HoVO4 synthesized via a sonochemical-assisted route and triethylenetetramine (TETA) was used as a capping and precipitation agent. The experiments were carried out under a probe as sonication source, and its power was adjusted in 30 W (9 kHz), 50 W (15 kHz) and 80 W (24 kHz) for different samples. The obtained nanostructures were characterized by surface analytical and spectral techniques includes XRD, FT–IR, SEM, TEM and UV–visible spectra measurements. The HR–SEM images reveal that HoVO4 exists as a spindle-shape with spherical morphology together. HR–TEM images reveal that prepared catalyst has a spherical structure with uniform particle size. The results outline 67.6% elimination of methyl violet dye within 90 min under UV light in the presence of the optimal nano-sized formulation of 24.5 nm size. The prepared photocatalyst possesses high stability and reusability without appreciable loss of catalytic activity up to three runs.