Nanoheterojunctions MnCo2O4 nanoparticles anchored on mesoporous TiO2 networks for superior photocatalytic ability

Abstract

Antibiotics have been observed in industrial and domestic wastewater due to the extensive utilization of pharmaceuticals, demonstrating a considerable threat to aquatic ecosystems and human health. In this research, novel MnCo2O4 nanoparticles (NPs) accommodated on porous TiO2 networks were prepared by sol-gel approach for tetracycline (TC) degradation. TEM images revealed that the MnCo2O4 NPs (5–10 nm) was accommodated on mesoporous anatase TiO2 (20–30 nm). The 3% MnCo2O4/TiO2 photocatalyst displayed the maximum photocatalytic ability among the synthesized samples, including commercial P-25 and pristine TiO2, which indicated a high photocatalytic activity of 100% within 60 min of illumination time. The rate constants (k) values revealed that 3%MnCo2O4/TiO2 nanocomposite was 0.0479 min−1, which was about 18.4 and 47.9 folds greater than that of TiO2 NPs and P-25. The increased photocatalytic performance of MnCo2O4/TiO2 was ascribed to extending visible light response and promoting separation rate of electron-hole. Additionally, the unique mesostructured with the high surface area provided an abundant active site and outstandingly reduced MnCo2O4 aggregation. Meanwhile, the synthesized 3%MnCo2O4/TiO2 photocatalyst displayed excellent stability after five cycles. The photocatalytic mechanism over the heterojunction MnCo2O4/TiO2 nanocomposites was addressed in detail. The obtained mesostructure photocatalyst with a large surface area through this reasonable procedure strategy can significantly degrade and mineralize the organic contaminants in industrial and domestic wastewater under visible light.