Photochemical Pre-Treatment to Quantify Iron in Thin Films

Metal-based catalysts are indispensable in modern chemistry and one of the biggest challenges for industrial applications is to quantify their performance and stability. The metrics of performance can be obtained in terms of the turnover number and turnover frequency, and the stability might be associated with the leaching of the heterogeneous catalysts. Thus, metal quantification is the starting point to understand and evaluate the features of catalysts. Among the technologies for metal determination, spectrophotometric analysis stands out for being cheap and easy to perform. However, the challenge is the sample preparation to direct quantification from the heterogeneous materials. Herein, it is shown how important is the photochemical pre-treatment for the quantification of the total iron from heterogeneous thin films composed of iron-based materials. The photochemical approach was used to ensure a full dissociation of iron ions before the quantification. This method was revealed to be highly effective and precise, having a wide range of applications for different iron-based catalysts.金属基催化剂在现代化学领域中不可或缺，而工业应用面临的核心挑战之一，便是对其催化性能与稳定性进行定量表征。催化性能的量化指标可通过转换数（turnover number）与转换频率（turnover frequency）进行表征，催化剂的稳定性则可能与非均相催化剂（heterogeneous catalysts）的浸出行为相关。因此，金属元素定量分析是理解与评估催化剂性能特征的起点。在金属元素检测的各类技术中，分光光度法（spectrophotometric analysis）以成本低廉、操作简便的优势脱颖而出。然而，该方法的难点在于如何针对非均相材料完成直接定量所需的样品前处理。本文研究表明，光化学预处理（photochemical pre-treatment）对于准确定量铁基材料构成的非均相薄膜（heterogeneous thin films）中的总铁含量至关重要。该光化学方法可在定量检测前实现铁离子的完全解离，且被证实具有极高的有效性与精密度，可广泛应用于各类不同的铁基催化剂检测。