1：Experimental Design and Method Selection

A facile room-temperature deposition method was used to synthesize 3D coral-like Ag2S nanostructures. The formation mechanism was proposed by tracking the reaction process.

2：Sample Selection and Data Sources

Ag2S nanostructures were synthesized using silver nitrate (AgNO3) and thiourea (CS(NH2)2) as precursors. The photocatalytic performance was evaluated by decomposing methyl orange (MO) under simulated sunlight.

3：List of Experimental Equipment and Materials

Silver nitrate (AgNO3), thiourea (CS(NH2)2), oleamide (OLA), 1-octadecylamine, sodium thiosulfate pentahydrate (Na2S2O3·5H2O), sulfur (S), sodium sulfide nonahydrate (Na2S·9H2O). Equipment: X-ray diffractometer (XRD-6000, Shimadzu), field emission scanning electron microscopy (JSM-7001F, JEOL), automatic gas adsorption analyzer (ASIQ-C, American Quanta), lock-in amplifier (SR830, Stanford Research Systems, Inc.), light chopper (SR540, Stanford Research Systems), xenon lamp (CHFXM500, Trusttech), monochromator (SBP500, Zolix), electrochemical workstation (LK 2006A, Tianjin Lanlike).

4：Experimental Procedures and Operational Workflow

1. Preparation of Ag2S NCs: AgNO3 and thiourea were dissolved in distilled water and mixed with stirring. The product was collected by centrifugation, washed, and dried. 2. Preparation of Ag2S NPs, NWs, and MCs: Different methods were used for each morphology, involving dissolution of precursors, mixing, and thermal treatment. 3. Characterization: XRD, SEM, BET surface area, SPS, EIS, and photocatalytic measurements were conducted.

5：Data Analysis Methods

XRD for phase identification, SEM for morphology, BET for surface area and porosity, SPS for surface photovoltaic properties, EIS for charge transfer resistance, and photocatalytic measurements for activity evaluation.