Wet photochemical filling: a new low-diameter tube-filling method based on differentiated nanotube surfaces

摘要

In this work, by using a simple chemical morphology freezing method novel low-diameter tubular nanocomposites (TiO2-NTs@SiO2) with differentiated surfaces are prepared, in which the TiO2 layer acts as a photoactive inner surface and the SiO2 layer acts as an insulating outer surface. Because of the photoactivity of TiO2, under UV light irradiation, only the inner TiO2 surface can photoreduce a H2PtCl6 precursor solution to Pt nanoparticles on its surface. As a result, Pt nanoparticles are highly selectively filled in the tube inner channel after this wet photochemical filling process. Due to the high dispersity of Pt nanoparticles in the channel, the method can improve catalytic activity efficiently by increasing the ultimate effective Pt load. in photocatalytic H2-production experiments, nanotubes filled with 6 wt% Pt show the highest photoactivity of all the samples; this activity is twice that obtained with TiO2 nanoparticles loaded with 0.6 wt% Pt.