Coating process of silica film on TiH₂ particles and hydrogen release characteristics

The coating process of TiH₂ particles with SiO₂ layers, and the effect of the coating layer on hydrogen release characteristic of TiH₂ powders were studied experimentally. The gelation rate of silicic acid is an important factor for controlling the surface morphologies of coating layers. When the concentration of SiO₃^2- is about 0.5 mol/L, the condensation rate of silicic acid is appropriate for the formation of a homogeneous and dense coating membrane. The results of hydrogen release at 700°C show that TiH₂ particles coated with silicon dioxide layers can efficiently delay the starting time of hydrogen release of TiH₂ powders to 60-100 s.