LaFe$lt;inf$gt;1-x$lt;/inf$gt;Mg$lt;inf$gt;x$lt;/inf$gt;O$lt;inf$gt;3$lt;/inf$gt; Ultrafine Powders Synthesized by Solution Combustion and Its Photocatalytic Performances

Mg 2+ doped LaFeO 3 ultrafine powders were synthesized by solution combustion method. Effects of Mg 2+ doping content on phase composition, microstructure and photocatalytic performances of the synthesized powders were investigated by XRD, SEM, BET, and UV-Vis. The results show that Mg 2+ substitutes for Fe 3+ to form LaFe 1-x Mg x O 3 (0x0.2) limited solid solution. When Mg 2+ doping content is 0.1, LaFe 0.9 Mg 0.1 O 3 powder has a maximum specific surface area (43.46 m 2 /g) and smaller particle size (100 nm and 150 nm in diameter and length direction, respectively). It has the best photocatalytic ability with photodegradation efficiency of 75.2% to methyl orange (10 mg/L) under high-pressure mercury lamp irradiation for 180 min. It increases 26.5% than that of the pure LaFeO 3 under the same experimental conditions, and the reaction may be described as the pseudo first order kinetics equation.