Introduction of Pr₂CrMnO₆/CrMn_1.5O₄ nanocomposites as a visible-light photocatalyst: Green sol-gel auto-combustion synthesis, structural characterization and comparative study

With the expansion of industrial activities and the global warming problem, the recent technological advances on the application of an efficient photocatalyst for environmental pollution removal are especially desired. However, visible light-induced degradation of organic pollutants in water resources is of great importance. Herein, we report the development of a novel double perovskite Pr₂CrMnO₆-based oxides (PCMO) for photocatalytic abatement of manufactured coloring agent like methyl orange (MO) under visible light. An environmentally friendly auto-combustion route was employed to prepare PCMO nanoparticles, in which the various amounts of mango juice act as fuel sources. As a result, a morphologically desirable sample was achieved in the presence of 15 mL mango juice with composition of Pr₂CrMnO₆/CrMn_1.5O₄. From DRS data, the optical band gap of the PCMO nanostructures was calculated as 2.0 eV. Using VSM analysis, this compound exhibited a dual magnetic behavior, ferromagnetic nature in low field and paramagnetic nature in up field. The photocatalytic results indicated that PCMO nanostructures are most effective in photocatalytic activity when the dye concentration is 15 ppm and the catalyst dosage is 0.05g. Following 120 min of light irradiation at this condition, it was found that the maximum yield is 95.1%. As part of the investigation into the mechanism of photocatalysis, benzoic acid, EDTA, and benzoquinone were used as •OH, h⁺, and •O₂⁻ scavengers, respectively. In the recyclability test, the photocatalytic efficiency decreased from 95.1% to 88.0% after five consecutive cycles.