Permeation and photo-induced outgassing of deuterium in hollow glass microspheres doped with titanium.

The influences of titanium (Ti) doping on the gas retention capacity and photo-induced outgassing behavior of hollow glass microspheres (HGMs) were investigated. It was found that the addition of Ti4+ did not significantly impact the permeability of HGMs, which exhibited a pressure half-life over 100 days. The K p of Ti3+-doped HGMs was found to be 3–8 times higher than that of Ti4+-doped HGMs, where oxygen vacancies and phase interfaces in the glass shell act as gas diffusion passages. Fortunately, these defects can be eliminated by heat treatment at 600 °C to improve the gas retention capacity. Moreover, photo-induced outgassing was observed in Ti3+-doped HGMs due to the absorption of light in the range of 400–2400 nm, while no absorption or response to illumination was observed in Ti4+-doped HGMs. Notably, the photo-induced outgassing was found to be controllable and repeatable without attenuation of response rate or intensity over four trials. photo-induced gas release in Ti3+ doped hollow glass microsphere. [Display omitted] • Ti3+-doped spheres are photoactive during outgassing, while Ti4+-doped are not. • The photo-induced outgassing of spheres is repeatable and controllable. • The gas retention capacity of Ti3+-doped spheres is improved by annealing. • Ti4+-doped spheres exhibit low permeability, benefitting hydrogen storage. [ABSTRACT FROM AUTHOR]