Improved photocatalytic activity of SnO₂-ZnAl LDH prepared by one step Sn⁴⁺ incorporation

SnO₂-ZnAl LDH with a molar ratio Zn/(Al+Sn) 3/1 (Sn⁴⁺ contents 0.1-0.4mol%) were prepared in one step by the co-precipitation method. The ZnAl LDH intercalated with carbonate ions and the composite of ZnAl LDH formed together with SnO₂ were characterized by XRD, SEM, HRTEM and complementary spectroscopies such as FTIR, XPS and UV-Vis. The EDX and AAS was performed for the compositional analysis. The effect of the Sn⁴⁺ content on the opto-electronic properties of the dried SnO₂-ZnAl LDH composites were evaluated on the phenol photodegradation under UV light irradiation. The mineralization degree of the photocatalysts was determined after 2h of reaction by TOC analysis. The SnO₂-ZnAl LDH composites that showed the highest photocatalytic activity were compared with ZnAl LDH sample impregnated with Sn⁴⁺ cations. The effect of the presence of the Zn₅(CO₃)₂(OH)₆ as precursor for the formation of the ZnAl LDH as well as the methodology of synthesis on the photocatalytic properties of the composites were studied. A possible mechanism of the OH radical formation and electron-hole charge separation in the improvement photocatalytic reaction were discussed.