College of Architecture and Civil engineering, Beijing University of Technology, Beijing 100124, China.
College of Architecture and Civil engineering, Beijing University of Technology, Beijing 100124, China.
J Environ Sci (China). 2020 Aug;94:40-51. doi: 10.1016/j.jes.2020.03.044. Epub 2020 Apr 16.
Photo-responsive adsorption-photocatalysis nanocomposites are generally used in water and wastewater decontamination; however, the prolonged adsorption capacity of composites and the role of adsorption in concomitant photocatalysis are typically neglected. These composites can be regenerated under light irradiation as their adsorption capacity decreases. Herein, a novel adsorption-photocatalysis bifunctional nanocomposite, Bi-doped TiO supported on powdered activated carbon (BiO/TiO/PAC), was prepared using the sol-impregnation-hydrothermal procedure. BiO/TiO/PAC with a secondary calcination temperature of 700°C under a nitrogen atmosphere was selected for maximum adsorption capacity on Methyl Orange (MO). The composite displayed an excellent adsorption capacity and was easily separated and recycled. The results demonstrate that 71.2% photocatalytic regeneration efficiency could be attained under visible light irradiation for 1 hr at an intensity of 750 W/m and pH 7. Characterization of the as-prepared BiO/TiO/PAC nanocomposite (700°C) indicates that it possesses a highly specific surface area and great optical properties, showing bifunctional adsorption-photocatalysis characteristics. The p-n heterojunction of the composite played a dominant role in the photocatalytic regeneration process, and effective degradation of MO could be achieved along with composite regeneration.
光响应吸附-光催化纳米复合材料通常用于水和废水的净化；然而，复合材料的吸附容量延长和吸附在伴随光催化中的作用通常被忽视。这些复合材料可以在光照射下再生，因为它们的吸附容量会降低。在此，采用溶胶浸渍-水热法制备了一种新型的吸附-光催化双功能纳米复合材料，Bi 掺杂的负载在粉末状活性炭上的 TiO（BiO/TiO/PAC）。在氮气气氛下，选择二次煅烧温度为 700°C 的 BiO/TiO/PAC 以获得对甲基橙（MO）的最大吸附容量。该复合材料表现出优异的吸附能力，易于分离和回收。结果表明，在可见光照射下，强度为 750 W/m、pH 值为 7 时，经过 1 小时的辐照，可达到 71.2%的光催化再生效率。对制备的 BiO/TiO/PAC 纳米复合材料（700°C）的表征表明，它具有高比表面积和优异的光学性能，表现出双功能吸附-光催化特性。复合材料中的 p-n 异质结在光催化再生过程中起主导作用，可实现 MO 的有效降解和复合材料的再生。
