Photocatalytic property of perovskite LaFeO3 synthesized by sol-gel process and vacuum microwave calcination

• LaFeO3 was synthesized by a sol-gel route followed with vacuum microwave calcination.
• The synthesis method reduces formation temperature and duration of LaFeO3 crystal.
• The LaFeO3 exhibits a superior visible photogradation activity on methyl orange.

Perovskite LaFeO3 nanoparticles with an orthorhombic structure were synthesized by a sol-gel route and subsequent vacuum microwave calcination. The effects of vacuum microwave calcination temperature and duration on the formation of LaFeO3 single phase were investigated. The use of vacuum microwave calcination can effectively reduce the crystallization time of LaFeO3 nanoparticles. The synthesized LaFeO3 nanoparticles have a perfect crystal structure, a single phase composition without any impurity, uniform particle size, and a suitable energy band of ∼1.86 eV. According to the PL spectrum of LaFeO3 nanoparticles, the recombination rate of photo-generated electrons and holes can be reduced due to the use of vacuum microwave calcination. Furthermore, LaFeO3 nanoparticles calcined by vacuum microwave calcination have a superior visible photo-catalytic efficiency on organic dye methyl orange and methyl blue, and a higher photodegradation efficiency rate, compared to those calcined by conventional calcination. LaFeO3 nanoparticles obtained by vacuum microwave calcination at 700 °C for 30 min (sample MW-700-30) exhibits superior photocatalytic efficiency, and the MB and MO dye solution in the presence of LaFeO3 nanoparticle becomes colorless during 240 min under visible light irradiation. The photodegradation process of MB on the as-synthesized LaFeO3 follows a pseudo-first-order kinetic process.

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