Photocatalytic Functionalized Aggregate: Enhanced Concrete Performance in Environmental Remediation
Photocatalytic Functionalized Aggregate: Enhanced Concrete Performance in Environmental Remediation
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DOI：
10.3390/buildings9020028
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发表时间：
2019-02-01
期刊：
影响因子：
3.8
通讯作者：
Macphee, Donald E.
中科院分区：
文献类型：
--
作者：
Hakki, Amer;Yang, Lu;Macphee, Donald E.
有效的光催化活性结构的工程是非常重要的，因为它引入了一些现有的空气污染问题的解决方案。这实际上可以通过用合适的稳定粘合剂将颗粒光催化剂粘合到建筑材料（例如骨料）的表面来实现。然而，光催化活性材料对空气污染物和阳光的可及性是在设计这种结构时必须仔细考虑的基本问题。在此，将不同量的商业TiO 2负载在作为聚集体的实例的石英砂的表面上，其中硅胶层充当光催化剂和载体之间的粘合剂。然后将由此制备的光催化活性聚集体负载在砂浆的表面上以测量它们的NOx去除性能。采用电子显微镜（SEM和TEM）、傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）和紫外-可见吸收光谱（UV-vis Absorption Spectroscopy）对材料进行了表征。如电子显微镜图像所示，成功地实现了光催化剂在载体表面的非常好的覆盖。红外光谱证实了化学键合，即，界面Ti-O-Si键，在光催化剂和二氧化硅层之间。根据ISO标准方法（ISO 22197-1）测试所获得的复合材料的光催化活性用于光催化去除氮氧化物。所获得的骨料暴露的砂浆已显示高达约。与其中光催化剂与水泥混合的样品相比，对NO去除的光催化性能高四倍，然而，硝酸盐选择性可受Ti-O-Si键合的影响。
Engineering of effective photocatalytically active structures is of great importance as it introduces a solution for some existing air pollution problems. This can be practically achieved through the bonding of particulate photocatalysts to the surface of construction materials, such as aggregates, with a suitable stable binding agent. However, the accessibility of the photocatalytically active materials to both the air pollutants and sunlight is an essential issue which must be carefully considered when engineering such structures. Herein, different amounts of commercial TiO2 were supported on the surface of quartz sand, as an example of aggregates, with a layer of silica gel acting as a binder between the photocatalyst and the support. The thus prepared photocatalytically active aggregates were then supported on the surface of mortars to measure their performance for NOx removal. The obtained materials were characterized by electron microscopy (SEM and TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and UV-vis Absorption Spectroscopy. Very good coverage of the support's surface with the photocatalyst was successfully achieved as the electron microscopic images showed. FTIR spectroscopy confirmed the chemical bonding, i.e., interfacial Ti-O-Si bonds, between the photocatalyst and the silica layer. The photocatalytic activities of the obtained composites were tested for photocatalytic removal of nitrogen oxides, according to the ISO standard method (ISO 22197-1). The obtained aggregate-exposed mortars have shown up to ca. four times higher photocatalytic performance towards NO removal compared to the sample in which the photocatalyst is mixed with cement, however, the nitrate selectivity can be affected by Ti-O-Si bonding.