Insights into promoted photocatalytic performance of nanoscale Sm2CrMnO6 double perovskite for organic pollutants degradation under visible light irradiation: Sol-gel auto-combustion synthesis, characterization and mechanisms

• The Sm 2 CrMnO 6 nanoparticles are synthesized successfully through novel low-cost sol-gel route. • Morphological of products were engineered through applying different chelating agents. • The structural properties of Sm 2 CrMnO 6 nanoparticles were characterized comprehensively. • The prepared Sm 2 CrMnO 6 showed prominent photocatalytic activity against dye. • The possible mechanism of photodegradation process was proposed via radical scavengers. Recently, the interest in photocatalytic water treatment has been increased in many aspects. Photocatalysis utilizes free solar energy to degrade various organic pollutants in water. In this study, a magnetic Sm 2 CrMnO 6 nanoparticle as photocatalyst was prepared using a novel, low-cost, and simple sol-gel auto-combustion method. Investigating UV–Vis diffuse reflectance spectroscopy (DRS) analysis revealed the optical band gap of 1.58 eV for as-obtained Sm 2 CrMnO 6 nanoparticles. This excellent optical band gap led to develop the Sm 2 CrMnO 6 nanoparticles as photocatalyst under visible light. Dual ferromagnetic-paramagnetic nature of resultant nano- Sm 2 CrMnO 6 has been revealed by vibrating-sample magnetometer (VSM) instrument. In order to explore the photodegradation yield of as-formed products, diverse circumstances on the removal of pollutant models including eriochrome black T (ECBT) and malachite green (MG) was employed, in which optimum dye concentration, and catalyst loading were identified to be 5 ppm and 50 mg/L under visible light. After 120 min, 98 % of ECBT dye molecules were destroyed by visible source.