Making glow toys from scratch

Summary by Krater

The creator attempts to make glow-in-the-dark zinc sulfide powder from scratch and dope it with copper to create glowing toys, finding that purity, precise proportions, and the addition of zinc oxide and ammonium chloride are critical for success.

From the video

Answers: How do you make glow-in-the-dark zinc sulfide powder from scratch?

• zinc sulfide synthesis
• glow-in-the-dark powder preparation
• copper doping zinc sulfide
• phosphorescence and fluorescence
• chemical purification of zinc sulfate

What it concludes

• Pure zinc sulfide on its own does not glow and must be doped with a metal like copper.
• Contaminants like iron can completely ruin the glow of zinc sulfide phosphors.
• Ammonium chloride acts as a halide flux to help copper incorporate into the zinc sulfide crystal structure during heating.
• A small amount of zinc oxide (formed from residual oxygen during firing) significantly increases fluorescence intensity.
• Strontium aluminate glows significantly brighter and longer than zinc sulfide, though it is more expensive and difficult to make.