NSF I/UCRC Center for Particulate & Surfactant Systems (CPaSS), Columbia University, New York, New York 10027, USA.
J Am Chem Soc. 2011 Jun 22;133(24):9536-44. doi: 10.1021/ja202266g. Epub 2011 May 27.
The impact of deposition and aggregation on (bio)chemical properties of semiconducting nanoparticles (NPs) is perhaps among the least studied aspects of aquatic chemistry of solids. Employing a combination of in situ FTIR and ex situ X-ray photoelectron spectroscopy (XPS) and using the Mn(II) oxygenation on hematite (α-Fe(2)O(3)) and anatase (TiO(2)) NPs as a model catalytic reaction, we discovered that the catalytic and sorption performance of the semiconducting NPs in the dark can be manipulated by depositing them on different supports or mixing them with other NPs. We introduce the electrochemical concept of the catalytic redox activity to explain the findings and to predict the effects of (co)aggregation and deposition on the catalytic and corrosion properties of ferric (hydr)oxides. These results offer new possibilities for rationally tailoring the technological performance of semiconducting metal oxide NPs, provide a new framework for modeling their fate and transport in the environment and living organisms, and can be helpful in discriminating between weakly and strongly adsorbed species in spectra.
沉积和聚集对半导体纳米粒子（NPs）的（生物）化学性质的影响，也许是固体水相化学中研究最少的方面之一。本研究采用原位傅里叶变换红外光谱（FTIR）和非原位 X 射线光电子能谱（XPS）相结合的方法，并以赤铁矿（α-Fe(2)O(3)）和锐钛矿（TiO(2)）NPs上的 Mn(II)氧化作用作为模型催化反应，发现通过将半导体 NPs 沉积在不同的载体上或与其他 NPs 混合，可以控制它们在黑暗中的催化和吸附性能。我们引入电化学中的催化氧化还原活性的概念来解释这些发现，并预测（共）聚集和沉积对氧化铁（氢氧化物）的催化和腐蚀性质的影响。这些结果为合理调整半导体金属氧化物 NPs 的技术性能提供了新的可能性，为其在环境和生物体中的命运和迁移建模提供了新的框架，并有助于在谱图中区分弱吸附和强吸附物种。
