Synthesis and characterization of highly efficient Te-doped Mn₃O₄ and s-g-C₃N₄ /Te- Mn₃O₄ nanocomposites as an excellent antimicrobial and photocatalytic agent

This work aims to synthesize manganese oxide nanoparticles (Mn₃O₄NPs) using a co-precipitation method and analyzed them through XRD, SEM and FT-IR. The XRD analysis confirmed the tetragonal hausmanite structure of the Mn₃O₄ NPs, while SEM revealed an average particle size of 9–20 nm. Kinetic studies demonstrated the efficient photooxidation of methylene blue with first-order kinetics under UV or visible light. Degradation efficiencies varied between 82% and 93% depending on the light source. Furthermore, we used the zone inhibition approach to assess the antibacterial potency of various Mn₃O₄ NP contents alongside human pathogenic bacteria, namely Escherichia coli and Staphylococcus aureus. The results of the qualitative antibacterial tests revealed that E. coli, a Gram-negative bacterium, is more sensitive to Mn₃O₄ NPs than are Gram-positive bacteria, with a maximum zone diameter of 28 mm (S. aureus). Alternatively, it was determined that S-g-C₃N₄/Te-Mn₂O₃ had the maximum antifungal activity against Alternaria solani at 28.9 mm and against. Colletotrichum gloeosporioides at 47.3 mm.