1：Experimental Design and Method Selection:

Zinc oxide was reacted with phosphoric acid at various pH values to synthesize a novel white pigment. The chemical composition, powder properties, photocatalytic activities, colors, and smoothness of these pigments were studied.

2：Sample Selection and Data Sources:

Zinc oxide was added to phosphoric acid solutions at a molar ratio of P:Zn = 1:1, then shaken in water at 80 °C for 1 h.

3：List of Experimental Equipment and Materials:

X-ray diffractometer (MiniFlex, Rigaku), Horiba FT-IR 720, SPS1500VR from Seiko Instruments, JSM-5510LV (JEOL), SA-CP3L (Shimadzu), UV2100 (Shimadzu), TES135 Plus Color Analyzer (TES Electrical Electronic), KES-SE (Kato Tech).

4：Experimental Procedures and Operational Workflow:

Samples were decanted, washed with water, and dried. Phase analyses were performed by XRD, IR spectra were recorded, and the ratios of phosphorus to zinc were calculated based on ICP atomic emission spectroscopy results.

5：Data Analysis Methods:

The shapes and sizes of the precipitate particles were estimated from SEM images and particle size distributions. The photocatalytic activity was estimated by measuring the degradation of methylene blue under 365 nm radiation.