Facile production of optically active hollow glass microspheres for photo-induced outgassing of stored hydrogen

Illumination of engineered hollow glass microspheres with near-infrared light is used to rapidly release stored gases, in particular hydrogen. Photo-induced outgassing of hydrogen is made possible by introducing optically active dopants into the glass such as cobalt. Recycled amber glass frit coated with polypropylene glycol and cobalt sulfate is converted into hollow glass microspheres with a simple, low-cost flame spraying method. Hollow glass microspheres made by this process release hydrogen more quickly when illuminated versus traditional outgassing with a heated oven. A simple model is proposed for engineering the geometry of the hollow glass microspheres.

► Cobalt-doped hollow glass microspheres are produced by a simple flame spraying process. ► Cobalt doping enables optical outgassing of stored hydrogen. ► Microsphere geometry can be predicted using a basic model.