Abstract:
Titanium dioxide (TiO2) has been extensively studied as a suitable material for a wide range of fields including catalysis and sensing. For example, TiO2-based nanoparticles are active in the catalytic conversion of glucose into value-added chemicals, while the good biocompatibility of titania allows for its application in innovative biosensing devices for glucose detection. A key process for efficient and selective biosensors and catalysts is the interaction and binding mode between the analyte and the sensor/catalyst surface. The relevant features regard both the molecular recognition event and its effects on the nanoparticle electronic structure. In this work, we address both these features by combining two first-principles methods based on periodic boundary conditions and cluster approaches (CAs). While the former allows for the investigation of extended materials and surfaces, CAs focus only on a local region of the surface but allow for using hybrid functionals with low computational cost, leading to a highly accurate description of electronic properties. Moreover, the CA is suitable for the study of reaction mechanisms and charged systems, which can be cumbersome with PBC. Here, a direct and detailed comparison of the two computational methodologies is applied for the investigation of d-glucose on the TiO2 (100) anatase surface. As an alternative to the commonly used PBC calculations, the CA is successfully exploited to characterize the formation of surface and subsurface oxygen vacancies and to determine their decisive role in d-glucose adsorption. The results of such direct comparison allow for the selection of an efficient, finite-size structural model that is suitable for future investigations of biosensor electrocatalytic processes and biomass conversion catalysis.
摘要:
二氧化钛(TiO2)已被广泛研究为适用于包括催化和传感在内的广泛领域的材料。例如,基于TiO2的纳米颗粒在将葡萄糖催化转化为增值化学品方面具有活性,而二氧化钛的良好生物相容性允许其应用于葡萄糖检测的创新生物传感装置。高效和选择性生物传感器和催化剂的关键过程是分析物和传感器/催化剂表面之间的相互作用和结合模式。相关特征涉及分子识别事件及其对纳米粒子电子结构的影响。在这项工作中,我们通过结合基于周期性边界条件和聚类方法(CA)的两种第一原理方法来解决这两个特征。虽然前者允许研究延伸的材料和表面,CA仅关注表面的局部区域,但允许使用具有低计算成本的混合泛函。导致对电子特性的高度精确描述。此外,CA适用于反应机理和带电系统的研究,这对PBC来说可能很麻烦。这里,对两种计算方法进行了直接和详细的比较,以研究TiO2(100)锐钛矿表面上的d-葡萄糖。作为常用的PBC计算的替代方法,CA被成功地用于表征表面和地下氧空位的形成,并确定它们在d-葡萄糖吸附中的决定性作用。这种直接比较的结果允许选择有效的,有限尺寸的结构模型,适用于生物传感器电催化过程和生物质转化催化的未来研究。