College of Science, Huazhong Agricultural University, 430070, Wuhan, P. R. China.
Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, P. R. China.
Chemistry. 2022 Dec 20;28(71):e202202494. doi: 10.1002/chem.202202494. Epub 2022 Oct 26.
The piezo-Fenton system has attracted attention not only because it can enhance the Fenton reaction activity by mechanical energy input, but also because it is expected to realize a class of stimuli-responsive advanced oxidation systems by regulating energy input and hydrogen peroxide self-supply, thus greatly enriching the application possibilities of Fenton chemistry. In this work, a series of Fe-doped g-C N (g-C N -Fe) as a piezo-Fenton system were synthesized where the iron stably immobilized through Fe-N interaction. The piezo-induced electrons generate on g-C N matrix support the conversion of Fe(III) to Fe(II) and promote rate-limiting step of Fenton reaction. With the optimal Fe loading, g-C N -0.5Fe can achieve methylene blue (MB) degradation under ultrasonic treatment with first-order kinetic rate constants of 75×10 min . Most importantly, the g-C N -Fe can maintain good catalytic activity in a wide pH range (pH=2.0∼9.0) and be cyclic used without iron leaching to solution (<0.001 μg ⋅ L ), overcoming the disadvantage of traditional Fe-based Fenton catalysts that can only be applied under acidic conditions and prone to secondary pollution. In addition, g-C N -0.5Fe also exhibits antibacterial properties of Escherichia coli and Staphylococcus aureus under ultrasound. Hydroxyl radicals mainly contribute to the degradation of MB and the sterilization process. Our work is an attempt to clarify the role of g-C N -Fe in the conversion of mechanical energy to ROS and provide inspirations for the piezo-Fenton system design.
压电芬顿系统不仅因为其可以通过机械能输入来增强芬顿反应活性而受到关注，而且还因为它有望通过调节能量输入和过氧化氢自供给来实现一类刺激响应的高级氧化系统，从而极大地丰富了芬顿化学的应用可能性。在这项工作中，我们合成了一系列通过 Fe-N 相互作用稳定固定铁的 Fe 掺杂 g-C3N4（g-C3N4-Fe）作为压电芬顿系统。g-C3N4基质上的压电诱导电子支持 Fe(III)到 Fe(II)的转化，并促进芬顿反应的限速步骤。在最佳的 Fe 负载下，g-C3N4-0.5Fe 可以在超声处理下实现亚甲基蓝（MB）的降解，一级动力学速率常数为 75×10-2min-1。最重要的是，g-C3N4-Fe 在很宽的 pH 范围（pH=2.0∼9.0）内都能保持良好的催化活性，且不会发生铁浸出到溶液中（<0.001μg·L-1）的情况，克服了传统的基于 Fe 的芬顿催化剂只能在酸性条件下应用且易于产生二次污染的缺点。此外，g-C3N4-0.5Fe 在超声下对大肠杆菌和金黄色葡萄球菌也表现出抗菌性能。羟基自由基主要贡献于 MB 的降解和杀菌过程。我们的工作试图阐明 g-C3N4-Fe 在机械能向 ROS 转化中的作用，并为压电芬顿系统的设计提供启示。
