1：Experimental Design and Method Selection:

The study uses a photo-induced reduction method with monochromatic light for synthesizing silver nanoparticles, employing sodium citrate as a capping agent without additional reducing agents. The rationale is to provide an eco-friendly and cost-effective approach with controlled particle size and shape through wavelength variation.

2：Sample Selection and Data Sources:

Samples are prepared from aqueous solutions of silver nitrate and citric acid, with deionized water used as the solvent. Selection is based on standard chemical purity (99% for both reagents).

3：List of Experimental Equipment and Materials:

Silver Nitrate (99%, SAP), Citric Acid (99%, Merck), Aqua DI from Millipore Milli-Q system, X-ray diffractometer (PANalytical, USA), UV-Visible Spectrophotometer (Genesys 10S, Thermo-Fischer, USA), circulating water bath, incubator, and monochromatic light sources (specific wavelengths not detailed).

4：Experimental Procedures and Operational Workflow:

A 3 mM citrate solution is slowly added to 20 ml of 1 mM AgNO3 solution under constant stirring in dark conditions. The mixture is illuminated with different monochromatic lights until color change occurs, with temperature maintained between 20-25°C using a water bath. Samples are then stored in dark at 20°C.

5：Data Analysis Methods:

UV-Vis spectroscopy is used to analyze absorption spectra (300-700 nm range) for surface plasmon resonance, and XRD is employed to determine crystal structure and phase using Cu-Kα radiation at 40 kV and 20 mA, with data analyzed via Debye-Scherrer equation for particle size calculation.