Ion exchange synthesis of Ag+ incorporated LiAlO2 and its application in photodegradation of organic dyes

Abstract

The present work aimed at the synthesis, characterization and photodegradation studies of visible light active silver ion (Ag+) incorporated LiAlO2 catalyst. Ethylene glycol assisted sol–gel method was adopted to prepare LiAlO2 at 700 °C. AgAlO2 was synthesized by cation exchange of LiAlO2 by the solid-state method at 300 °C. The structural and optical properties were characterized by powder X-ray diffraction and UV–Vis diffuse reflectance spectroscopy respectively. The scanning electron microscopy (SEM) provided the morphological information of as-prepared samples. LiAlO2 and AgAlO2 were crystallized in a tetragonal lattice (space group P412121) and orthorhombic (space group Pna21) respectively. The bandgap energy of the samples was determined by the Kubelka–Munk (KM) plot. SEM measurements revealed the flower-like hierarchical shape particles. The photocatalytic properties of these samples were evaluated by the degradation of methylene blue and rhodamine B dyes. The mechanistic degradation pathway of RhB was studied using radical quenchers. The rate of recombination of the charge carriers during photocatalysis was discussed.