Dual Applications in Colorimetric Mercury Ion Sensing and Catalytic Reduction Using Novel Magnolia loebneri Derived Silver Nanoparticles

Water pollution from various aquatic pollutants, including dyes, nitroaromatic compounds, and heavy metal ions, has become a significant global issue for human health and the environment; therefore, designing a simple, economical, and eco‐friendly approach to address water pollution is highly desirable. In this study, sunlight and Magnolia loebneri flower (MLF) extract served as natural resources to synthesize silver nanoparticles (AgNPs) in an environmentally friendly manner. The synthesized MLF AgNPs demonstrated multipurpose applications, including as an effective nanoprobe for the specific detection of Hg 2+ ions, and exhibited catalytic activities for the reduction of nitroaromatics and dye degradation. The produced MLF AgNPs were characterized using a variety of analytical techniques. UV‐Vis spectroscopy revealed a characteristic surface plasmon resonance (SPR) band at 412 nm. The MLF AgNPs were capped by phenols and amino acids according to the Fourier transform infrared (FT‐IR) spectral results. TEM confirms that AgNPs are spherical and have an average diameter of 9 ± 0.8 nm. MLF AgNPs exhibit fast colorimetric detection of Hg 2+ in spiked real samples, including tap water, river water, and artificial cerebrospinal fluid (ACSF). It has great selectivity and sensitivity, with a LOD of 0.8 µM. Additionally, MLF AgNPs demonstrated strong catalytic performance toward the reduction of nitroaromatics, including 4‐NP, NPM, and NFM, as well as degrading hazardous organic dyes, including methylene blue, rhodamine B, and methyl orange.