Enhanced photocatalytic efficiencies over A-sites substituted LaFeO3/ZnO nanocomposites

Perovskite oxide LaFeO3 (LF) is extensively used in the advanced technology such as electrode materials of solid oxide fuel cells [1], catalyst, high-temperature oxygen-permeable membranes, gas sensors, magnetic materials, super conductors, and so on. Nanocrystal perovskite oxide lanthanum orthoferrite is a P-type semiconductor with excellent properties such as high thermal stability, non-toxic and high-efficiency. LF has an orthorhombic perovskite structure. It is still challenging to obtain novel desired A- or B-sites substituted compounds structured of LF with a lot of applications that may changes the composition and symmetry of the perovskite and create cation or oxygen vacancies, which have a major effect on the band structures and photocatalytic activity of these materials. Moreover, many other properties, such as adsorption properties can also be designed by substitution on both A and B sites. In addition, doping of the X site could also affect the structure and BG of perovskites. The substitutions at A and/or B site of LF carried out by many ions such as Ag, Zn, Pb, Cr, Co are observed to have a great influence on the particle size, magnetic properties and photocatalytic activity of LF. In the past ten years, much attention has been paid to investigate how can be possible to improve photocatalytic activity of LF powders by doping elements. Muhammad Humayun et al. [2] Synthesis of ZnO/Bi-doped porous LF nanocomposites as highly efficient nano-photocatalysts and the prepared materials showed significantly improved visible-light activities. Among several perovskites it has been found that LF is visible-light photocatalytic active due to its excellent optoelectronic properties and narrow band gap in visible light region. Which makes it a candidate for photocatalytic reaction. However, single LF perovskite catalyst also exhibit high recombination of photogenerated electron/hole pairs which weakens the function of the photocatalytic performance and doesn’t show the complete degradation of organic pollutant, which is attributed to the low utilization of visible-light excited high level energy electrons and limited visible-light absorption.