High efficient solar light photocatalytic degradation of malachite green by solid state synthesized Bi2Sn2O7 and Bi2MxSn2O7 (M = Y3+, Eu3+, Gd3+ and Yb3+) nanomaterials

Nanostructured Bi2Sn2O7 and Bi2MxSn2O7 (M = Y3+, Eu3+, Gd3+ and Yb3+) nanomaterials were synthesized by conventional one-step solid state crystal growth reactions among Bi(NO3)3, SnCl2 and M2O3 raw materials at 800 ̊C for 10 and 15 h. The doped nanomaterials were synthesized to study the capacity of the crystal system to locate each of the dopant ions into the crystal system cavities. The synthesized nanomaterials were characterized by powder X-ray diffraction (PXRD) technique. Rietveld analysis showed that the obtained materials were crystallized well in orthorhombic crystal structure with the space group Aba2. The PXRD data revealed that dopant ion type had a considerable influence on the crystal phase purity of the obtained targets. The morphologies of the synthesized materials were studied by field emission scanning electron microscopy (FESEM) technique. Ultraviolet-visible spectra analysis showed that the synthesized nanomaterials had strong light absorption in the ultraviolet light region. Photocatalytic performance of the synthesized nanomaterials was investigated for the degradation of pollutant Malachite Green under solar light condition. The optimum conditions were modeled and obtained by design expert software for Bi2Sn2O7 that was synthesized at 800 ̊C for 10 h which were 0.06 mL H2O2, 12 mg catalyst and 40 min for the removal of 50 mL of 40 ppm MG solution. The degradation yield in these conditions was 100 %. The photocatalytic degradation fitted to the Langmuir–Hinshelwood kinetic model. As a result of the model, the kinetic of degradation followed a pseudo-zero-order kinetic model.