1：Experimental Design and Method Selection:

The synthesis of zirconia nanoparticles was initiated by dissolving zirconyl nitrate hydrate in double distilled water at 60°C under vigorous stirring until a clear solution was obtained. Ammonia solution was added dropwise to form a gel, which was then washed, filtered, and dried. The dried gel was annealed at various temperatures for 2 h.

2：Sample Selection and Data Sources:

The as-prepared gel and annealed powders at different temperatures were used for analysis.

3：List of Experimental Equipment and Materials:

Zirconyl nitrate hydrate, ammonia solution, double distilled water, acetone, ultrasonic cleaner, muffle furnace, X-ray diffractometer, thermal analyzer, FTIR spectrometer, HR-TEM, scanning electron microscope with EDAX unit, UV-Visible spectrophotometer.

4：Experimental Procedures and Operational Workflow:

The gel was formed, washed, dried, and annealed at specified temperatures. The annealed powders were then characterized using various techniques to study their structural, thermal, and optical properties.

5：Data Analysis Methods:

XRD patterns were analyzed for phase identification, TGA/DTA for thermal behavior, FTIR for vibrational bands, HR-TEM for morphology, and UV-Vis for optical properties.