1：Experimental Design and Method Selection

Precipitation method was used to synthesize Zn-doped Al2O3 nanoparticles. XRD, SEM, TEM, XPS, FT-IR and PL studies were performed to characterize the synthesized nanoparticles.

2：Sample Selection and Data Sources

Aluminium (III) chloride and zinc chloride were used as the host and dopant precursor salts. De-ionized water and liquid ammonia were used as the solvent and precipitating agent, respectively.

3：List of Experimental Equipment and Materials

X-pert PRO analytical PW340/60 diffractometer, HITACHI S-3000H scanning electron microscope, 200 kV Tecnai-20 G2 transmission electron microscope, K-AlphaTM+ X-ray photoelectron spectrophotometer, Perkin Elmer RX-1 spectrophotometer, Varian Cary Eclipse Fluorescence spectrophotometer.

4：Experimental Procedures and Operational Workflow

0.1 M of aluminium (III) chloride was dissolved in a solution mixture of 140 mL de-ionized water and 10 mL liquid ammonia. The resultant solution was aged for 4 h after stirring well for 2 h using a magnetic stirrer. After filtering, the precipitates were dried, calcined at 200 ?C for 1 h and grounded well to form Al2O3 nanoparticles.

5：Data Analysis Methods

The degradation efficiency (η) values of the Zn-doped Al2O3 catalysts were estimated using the relation η = (1 ? C/C0) × 100. The photocatalytic degradation kinetic of the Zn-doped Al2O3 catalysts were investigated using the pseudo first-order kinetic model.