Engineering Photocatalytic Cements: Understanding TiO2 Surface Chemistry to Control and Modulate Photocatalytic Performances
Engineering Photocatalytic Cements: Understanding TiO2 Surface Chemistry to Control and Modulate Photocatalytic Performances
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DOI：
10.1111/j.1551-2916.2010.03838.x
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发表时间：
2010-10-01
影响因子：
3.9
通讯作者：
Macphee, Donald E.
中科院分区：
文献类型：
--
作者：
Folli, Andrea;Pochard, Isabelle;Macphee, Donald E.
本工作解决的聚集/分散性能的两个商业二氧化钛作为光催化剂在混凝土技术中的应用。在不同pH值的不同离子介质（Na+、K+、Ca 2+、Cl-、SO（4）2-、合成水泥孔隙溶液）和真实的水泥浆体试样中测试了微米级m-TiO 2（平均粒径153.7 +/- 48.1 nm）和纳米级n-TiO 2（平均粒径18.4 +/- 5.0 nm）。结果表明，离子-离子相关性在水泥环境中TiO 2颗粒聚集中起着重要作用。本文提出了一种基于TiO 2表面化学的颗粒聚集模型，并用于解释真实的水泥浆体中的聚集现象。硬化水泥试样的扫描电子显微镜-能量色散X射线光谱研究完全证实了基于二氧化钛表面化学的定性模型。实验结果还表明，TiO 2聚集体的大小和性质如何显着影响含TiO 2的胶凝材料的整体光催化活性。
The present work addresses the aggregation/dispersion properties of two commercial titanias for application as photocatalysts in concrete technology. A microsized m-TiO2 (average particle size 153.7 +/- 48.1 nm) and a nanosized n-TiO2 (average particle size 18.4 +/- 5.0 nm) have been tested in different ionic media (Na+, K+, Ca2+, Cl-, SO(4)2-, synthetic cement pore solution) at different pHs and in real cement paste specimens. Results highlighted that ion-ion correlations play a fundamental role in TiO2 particles aggregation in the cement environment. A particle aggregation model derived from TiO2 surface chemistry is proposed here and used to justify such aggregation phenomena in real cement paste. Scanning electron microscopy-energy-dispersive X-ray spectroscopic investigations on hardened cement specimens completely confirmed the qualitative model based on titania surface chemistry. Experimental results also show how size and nature of TiO2 aggregates dramatically influence the overall photocatalytic activity of cementitious materials containing TiO2.