Synthesis of nano-structured lanthanum tungstates photocatalysts

Nano-particles of lanthanum tungstate were prepared through an optimized chemical precipitation reaction using the aqueous solutions of the ingredients. The optimization of the procedure was performed based on performing the so-called Taguchi robust design. The effects of various conditions influencing the size of the produced particles were evaluated using an orthogonal array. The optimally prepared lanthanum tungstate particles were found to be about 31 nm in diameter. The chemical and physical properties of the products were studied through X-ray diffraction, scanning electron microscopy, transmission electron microscopy, FT-IR spectroscopy, UV–Vis and Fluorescence. Also the band gap energy of the produced nanoparticles was assessed through UV–Vis diffuse reflectance spectroscopy. The optimally prepared nano-structures were evaluated as photocatalysts in the pho-degradation of methylene blue.