Titanium dioxide (TiO 2 ) is important for both fundamental studies and technical applications. Here we present laser power dependence Raman spectroscopic studies of rutile TiO 2 to reveal the response of various Raman-active lattice vibrations. Apparently, different vibrational modes display distinctive and reversible trends with the change of laser power. The Ti−O bond strength involved with different vibrational modes changes differently as the laser power changes. The relaxation time becomes shorter as the laser power increases. The changes of the bond strength and relaxation time can be related to the local temperature change with the laser power. The observed different behaviors in the vibrational modes suggest that the lattice movements along various directions face different temperature environments under the same light irradiation.

We report here the photocatalytic hydrogen generation from pure (deionized) water under simulated solar light with silicon carbide (SiC) nanoparticles, without the assistance of sacrificial reagents or precious metal co‐catalysts. We have studied the pH effects of the addition of methanol and the loading of a Pt co‐catalyst on the photocatalytic hydrogen generation efficiency of SiC nanoparticles. We have found that SiC nanoparticles display the best photocatalytic hydrogen generation efficiency in pure water. SiC nanoparticles show activity in both ultraviolet (UV) and visible‐light regions. The addition of methanol in water or loading of Pt nanoparticles on the surface lowers their activity. Thus, SiC nanoparticles may serve as an ideal model photocatalyst for future studies in generating hydrogen from pure water.