Pure α-MnO2 and Ag decorated α-MnO2 nanorods for photocatalytic activity

This paper details the production and analysis of alpha-MnO2 and Ag-decorated alpha-MnO2 nanorods by a hydrothermal technique. The main objective is to investigate their improved ability to break down methylene blue (MB) when exposed to UV light, with a specific focus on their photocatalytic properties. X-ray diffraction (XRD) verified the crystal structure and successful silver embellishment. The absorption spectrum of alpha-MnO2 and Ag-decorated alpha-MnO2 nanorods are analyzed through UV spectrum. The FTIR analysis revealed distinct Mn-O stretching vibrations, which exhibited variations that indicated the integration of Ag. The field emission scanning electron microscopy (FESEM) analysis showed the presence of rod-shaped alpha-MnO2 and circular Ag nanoparticles. The TEM and SAED patterns verified the nanoscale size and crystalline nature. EDAX analysis verified the presence of manganese (Mn), oxygen (O), and silver (Ag). The results of the photocatalytic tests demonstrated that the addition of silver (Ag) to alpha-MnO2 significantly improved its efficiency, reaching up to 94 %. This performance surpassed that of pure alpha-MnO2, which achieved an efficiency of 92 %. The kinetic experiments showed that the reaction rates were greater for nanorods coated with Ag (0.00661 min-1) compared to alpha-MnO2 (0.00363 min-1). Reusability experiments demonstrated consistent photocatalytic efficiency across numerous cycles. The TOC study revealed that 89 % of the dye had mineralized. The results emphasize the capability of Ag-decorated alpha-MnO2 nanorods for addressing environmental issues.