Single step facile synthesis of Cu-SnO₂/ZnO nanocomposite photocatalyst for methylene blue dye degradation in aqueous solution

Abstract

A Cu-SnO2/ZnO nanocomposite was prepared using a single-step facile synthesis method, sol-gel, for photocatalyst application. The XRD of Cu-SnO2/ZnO nanocomposite shows SnO2 and ZnO have tetragonal rutile and hexagonal wurtzite, which is similar to HRTEM and SAED data. The crystallite sizes of SnO2, ZnO, Cu-SnO2, SnO2/ZnO, and Cu-SnO2/ZnO are 8.50 nm, 29.12 nm, 7.10 nm, 6.42 nm, and 3.50 nm, respectively. The calculated energy band gap of SnO2, ZnO, Cu-SnO2, and Cu-SnO2/ZnO from the DRS measurements is 3.60 eV, 3.20 eV, 3.34 eV, 3.48 eV, and 3.09 eV, respectively. The photoluminescence spectroscopy shows that Cu-SnO2/ZnO nanocomposite has a higher defect density than another sample. The Fourier Transform Infrared (FTIR) spectroscopy identifies the functional groups of the Cu-SnO2/ZnO powder samples. The EDS spectra of the synthesized Cu-SnO2/ZnO nanocomposite indicated the existence of the elements of Cu, Sn, Zn, and O, respectively. The photocatalyst activities of Cu-SnO2/ZnO have higher efficiency, ~ 78%, than other samples.