Heterostructure of perovskite coupled graphitic carbon nitride for enhanced photodegradation under visible light

This study aimed to prepare and characterize LaFeO3 nanoparticles loaded graphitic carbon nitride (LFO/g-C3N4) photocatalyst and investigate the degradation organic pollutants under UV and natural sunlight exposure. It is observed that LFO nanoparticles of an average size of about 67 nm were distributed on g-C3N4 sheets through chemical bonding owing to the formation of a composite. Compared to LFO and g-C3N4, composite has a good absorption ability to harvest more UV and visible light due to its large surface area and pore size. The photocatalytic studies revealed that the g-C3N4/LFO composite exhibits higher catalytic efficiency and stability for methylene blue (MB) degradation under UV and visible light. Under UV light irradiation, the degradation efficiency of LFO, g-C3N4, and g-C3N4/LFO composite in synthetic wastewater was found to be around 50, 80 and 93 % with corresponding rate constants 0.05, 0.02, and 0.1 min(-1) in 30 min, respectively. Under natural sunlight, the composite degraded 97 % of MB in 180 min with a rate constant of 0.016 min(-1). The higher photocatalytic activity of the composite was attributed to the interfacial charge transfer between LaFeO3 and g-C3N4, which are responsible for effective charge separation in the composite. Further, it has been investigated that singlet oxygen species (O-1(2)) and hydroxyl radicals (center dot OH) are the main reactive species that contributed considerably to the complete degradation MB. The nanocomposite was also demonstrated to be a stable catalyst and can be reused without any further modification.