Ti-Si photocatalyst for producing hydrogen synthesized by shock wave

Ti-Si binary system shows several intermetallic compounds such as TiSi$_{2}$ and Ti$_{5}$Si$_{3}$. Among them TiSi$_{2}$ and Ti$_{5}$Si$_{3}$ show the higher reaction heat and can be initiated by shock wave and will propagate and complete in the form of combustion waves. As new functional materials, the light-absorption characteristics in UV-visible region of Ti-Si compound are ideal for solar applications and have a good photocatalytic activity of splitting water into hydrogen. We have synthesized TiSi$_{2}$ and Ti$_{5}$Si$_{3}$ compound with different Ti/Si ratios by shock-induced reaction arisen from the flyer impact driven by detonation of nitromethane. It is found that TiSi$_{2}$ is formed while flyer velocity is at 3.37km/s and exhibits certain photocatalytic activity of splitting water into hydrogen compared with the unreacted Ti+Si precursor shocked at 3.07km/s. Consequently, Ti$_{5}$Si$_{3}$ synthesized at 3.37km/s has much better photocatalytic activity of splitting water into hydrogen than that of TiSi$_{2}$ synthesized by shock wave at identical condition. The experimental results suggest that shock-induced reaction of Ti and Si with different ratios might get some novel functional materials for photocatalytic or photovoltaic application.