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 g_cat⁻¹ h⁻¹, which was 68% higher than that of the plain TiO₂ film.

中文翻译：

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SiO2蛋白石光子晶体的光子局域化效应增强二氧化钛光催化固氮活性

在环境条件下用水将氮光催化转化为氨是一种理想的策略。在目前的工作中，为了提高TiO ₂光催化剂的N ₂固定活性，通过将TiO ₂膜与SiO ₂蛋白石光子晶体（PC）膜耦合制备了双层TiO ₂ /SiO ₂蛋白石复合膜，及其测试了光催化固氮性能。结果表明，当SiO _{2 PCs的光子带隙(PBG)与TiO 2}的UV-Vis吸收边匹配时， SiO ₂的光子局域化效应PC 被最大化以促进 TiO ₂的光子捕获，导致更多的光生电子-空穴对用于 N ₂激活。_{SiO 2} PCs的光子局域化效应与复合膜中TiO ₂薄膜的厚度呈负相关。_{TiO 2} /SiO ₂蛋白石复合膜的固氮活性为42.6 μmol g _cat ^-1 h ^{-1 ，TiO} ₂膜厚度为700 nm，比普通膜高68%。 TiO ₂薄膜。