Ca aluminate/lanthanide metal fluoride for efficient removal of crystal violet

Ca aluminate/lanthanide metal fluoride nanocomposites were prepared via a simple photodeposition method. The nanocomposites are composed of orthorhombic Ca5Al6O14 and orthorhombic DyF3 (ErF3) phases with polycrystalline structure. Nanoflakes and irregular nanoscale particles coexist in the nanocomposites. The absorption edge of the Ca aluminate/lanthanide metal fluoride nanocomposites shifts to longer wavelength and the band gap is narrowed. The charge carrier separation efficiency of the nanocomposites is obviously improved which is beneficial for enhancing the photocatalytic activity. Nanocomposites with the ErF3 content of 0.2 mmol exhibit the highest catalytic activity toward crystal violet (CV). The enhanced photocatalytic activity of the nanocomposites for CV degradation is due to increased light absorption ability, reduced band gap, suppressed recombination of electron–hole pairs during the CV photodegradation.