Formation of ordered mesostructured TiO2 thin films: a soft coarse-grained simulation study

文献情報

出版日 2017-10-04

DOI 10.1039/C7CP05304E

インパクトファクター 3.676

著者

Qiyun Tang, Paula C. Angelomé, Galo J. A. A. Soler-Illia, Marcus Müller

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要旨

Ordered mesostructured TiO2 thin films are employed in diverse applications ranging from catalysis and sensing, to photovoltaic and lithium-ion batteries. Experimentally these mesostructured thin films are fabricated via a sol–gel process coupled with evaporation-induced self-assembly of a supramolecular template, where the concentration of hydrogen chloride (HCl) and water play vital roles. We employ a soft, coarse-grained model of the amphiphilic template Brij58 and spherical particles, representing titanium–oxo clusters, to study the role of HCl and water in the formation of mesostructured TiO2 thin films. The template–cluster and cluster–cluster interactions are reflected in the interaction terms δNBP and εPP, respectively. The results show that a decrease in HCl (increase in εPP) leads to the formation of large mesopores due to the strong attraction between particles, giving rise to a high dispersity index (low order) of the thin films. However, a decrease in water (increase in δNBP) will compensate for the entropic attraction between particles, resulting in thin films with low dispersity index (high order). The variation of the dispersity index in the δNBP–εPP plane provides an intuitive understanding that the slow evaporation of HCl could drive the film towards a uniform mesoporous state, whereas fast evaporation pushes the film through a non-uniform phase. These results indicate that even if the mass proportion of the surfactants Brij58 and titanium precursors is the same in the initial solution, the final mesoporous structures could be diverse, which was confirmed by the controlled experiments. We also confirm the post-processing-towards-order strategy by making the particle rearrangement available by weakening the εPP. The outlined procedure paves the way for soft, coarse-grained models to understand the complex co-assembly of transition metal clusters and amphiphilic surfactants towards the rational design of highly ordered mesoporous structures.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

Physical Chemistry Chemical Physics (PCCP) is an international journal co-owned by 19 physical chemistry and physics societies from around the world. This journal publishes original, cutting-edge research in physical chemistry, chemical physics and biophysical chemistry. To be suitable for publication in PCCP, articles must include significant innovation and/or insight into physical chemistry; this is the most important criterion that reviewers and Editors will judge against when evaluating submissions. The journal has a broad scope and welcomes contributions spanning experiment, theory, computation and data science. Topical coverage includes spectroscopy, dynamics, kinetics, statistical mechanics, thermodynamics, electrochemistry, catalysis, surface science, quantum mechanics, quantum computing and machine learning. Interdisciplinary research areas such as polymers and soft matter, materials, nanoscience, energy, surfaces/interfaces, and biophysical chemistry are welcomed if they demonstrate significant innovation and/or insight into physical chemistry. Joined experimental/theoretical studies are particularly appreciated when complementary and based on up-to-date approaches.