Abstract

Nano-TiO₂ photocatalysts doped with La–N(La–N–TiO₂) were prepared by solgel method. The La–N–TiO₂ was loaded on the cellulose/SiO₂ composite aerogel (La–N–TiO₂–CSA). La–N–TiO₂–CSA had both oil absorption and oil degradation functions under the sun. The static state water contact angle is up to 148° close to superhydrophobic surface. An apparent decomposition rate of oil is 92%, which is much higher than 26% of pure TiO₂. Under the visible light irradiation, the photocurrent density has increased by 50%. Characterization results show that LaONO₃ was uniformly distributed in TiO₂ crystal. Compared with pure TiO₂, the UV–Vis DRS data showed the absorption band of La–N–TiO₂ had extended to 441 nm. The La increased the valence band position and N lowered the conduction band position, which reduced the band gap of TiO₂ from 3.59 to 2.81 eV. The formation of LaONO₃ reduced carrier transfer resistance, and the migration rate and electron–hole separation efficiency were improved. The possible oil decomposition pathways were proposed.

Graphic abstract

中文翻译：

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La-N-TiO 2-纤维素/ SiO 2双功能气凝胶复合材料通过同时吸附和光催化有效去除油污

摘要

采用溶胶凝胶法制备了掺有La–N（La–N–TiO ₂）的纳米TiO ₂光催化剂。将La–N–TiO ₂负载在纤维素/ SiO ₂复合气凝胶（La–N–TiO ₂ –CSA）上。La–N–TiO ₂ –CSA在阳光下具有吸油和降解油的功能。接近超疏水表面的静态水接触角最大为148°。油的表观分解率为92％，远高于纯TiO _2的26％。在可见光照射下，光电流密度增加了50％。表征结果表明，LaONO ₃在TiO _2中均匀分布水晶。与纯TiO ₂相比，UV-Vis DRS数据显示La-N-TiO ₂的吸收带已扩展至441 nm。La增加了价带位置，N降低了导带位置，这将TiO ₂的带隙从3.59减小到2.81 eV。LaONO ₃的形成降低了载流子的传输阻力，并提高了迁移速率和电子-空穴分离效率。提出了可能的油分解途径。

图形摘要