In the present study, amino-functionalized carbon quantum dots (N-CQDs) were prepared from sugarcane bagasse using a simple one-pot hydrothermal method. Both ethylenedinitrilotetraacetic (EDTA) & ethylenediamine (EDA) were used as carbon and amino sources, respectively. The emerging utilization of natural carbon precursors is critically essential considering its low cost, eco-friendly, and unexploited by-products (e.g., sugarcane bagasse), which may have sustainable economic and strategic benefits. The as-prepared N-CQDs were characterized using High-Resolution Transmission Electron Microscope (HRTEM), Fourier Transform Infrared Spectroscopy (FTIR), UV-vis absorption spectroscopy, and photoluminescence spectroscopy. The influences of amine groups were investigated. The as-prepared N-CQDs photoluminescence intensity increased and quenched significantly with EDTA and EDA amino-functionalization, respectively, with the highest quantum yield at 21.21%, 2.4 times higher than non-functionalized CQDs. Furthermore, the amino-functional groups can alter the CQDs structure and particle size ranging from 4.197±1.058 nm to 9.704±1.428 nm. Hence, the N-CQDs produced exhibit highly tunable photoluminescence and particle size potentially applicable in diverse applications.

Water-soluble organic pollutants, such as phenolic compounds, have been exposed to environments globally. They have a significant impact on groundwater and surface water quality. In this work, different Mn₃O₄ catalysts were prepared for metal oxide activation of peroxymonosulfate (PMS) to remove the phenolic compound from the water environment. The as-prepared catalysts were characterized using thermogravimetric-differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. Furthermore, the effect of temperature and reusability of the as-prepared Mn₃O₄ catalysts is also investigated. The Mn₃O₄ nanoparticles (NPs) catalyst reveals an excellent performance for activating PMS to remove phenol compounds. Mn₃O₄ NPs exhibits 96.057% efficiency in removing 25 ppm within 60 min. The kinetic analysis shows that Mn₃O₄ NPs fitted into pseudo-first order kinetic model and exhibited relatively low energy activation of 42.6 kJ/mol. The reusability test of Mn₃O₄ NPs displays exceptional stability with 84.29% efficiency after three-sequential cycles. The as-prepared Mn₃O₄ NPs is proven suitable for phenolic remediation in aqueous solutions.