Enhanced photocatalytic activity of titanium dioxide in nitrogen fixation by the photon localization effect of SiO2 opal photonic crystals
Photocatalytic conversion of nitrogen to ammonia with water under ambient conditions is a desired strategy. In the present work, in order to increase the activity of the TiO2 photocatalyst for N2 fixation, bilayer TiO2/SiO2 opal composite membranes were prepared via coupling TiO2 films with SiO2 opal photonic crystal (PC) films, and their photocatalytic performance in nitrogen fixation was tested. It was shown that when the photonic band gap (PBG) of the SiO2 PCs matched with the UV-Vis absorption edge of TiO2, the photon localization effect of SiO2 PCs was maximized to promote the photon capture of TiO2, resulting in more photogenerated electron–hole pairs for N2 activation. The photon localization effect of SiO2 PCs is negatively correlated with the thickness of the TiO2 films in composite membranes. The nitrogen fixation activity of the TiO2/SiO2 opal composite membrane, with the thickness of TiO2 film being 700 nm, was found to be 42.6 μmol gcat−1 h−1, which was 68% higher than that of the plain TiO2 film.
危险品化学品经营许可证（带存储）