College of Environmental Science and Engineering, Biomedical Multidisciplinary Innovation Research Institute, Shanghai East Hospital, Tongji University, Shanghai 200092, China.
Key Laboratory of Yangtze River Water Environment, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China.
Proc Natl Acad Sci U S A. 2023 Jan 3;120(1):e2210211120. doi: 10.1073/pnas.2210211120. Epub 2022 Dec 27.
Controllable in situ formation of nanoclusters with discrete active sites is highly desirable in heterogeneous catalysis. Herein, a titanium oxide-based Fenton-like catalyst is constructed using exfoliated TiC MXene as a template. Theoretical calculations reveal that a redox reaction between the surface Ti-deficit vacancies of the exfoliated TiC MXene and HO molecules facilitates the in situ conversion of surface defects into titanium oxide nanoclusters anchoring on amorphous carbon (TiO@C). The presence of mixed-valence Ti (δ = 0, 2, 3, and 4) within TiO@C is confirmed by X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) characterizations. The abundant surface defects within TiO@C effectively promote the generation of reactive oxygen species (ROS) leading to superior and stable Fenton-like catalytic degradation of atrazine, a typical agricultural herbicide. Such an in situ construction of Fenton-like catalysts through defect engineering also applies to other MXene family materials, such as VC and NbC.
在多相催化中，可控的具有离散活性位的纳米团簇的原位形成是非常理想的。在此，使用剥离的 TiC MXene 作为模板构建了一种基于氧化钛的类芬顿催化剂。理论计算表明，剥离的 TiC MXene 表面 Ti 缺陷空位与 HO 分子之间的氧化还原反应有利于表面缺陷原位转化为锚定在无定形碳上的氧化钛纳米团簇（TiO@C）。X 射线光电子能谱（XPS）和 X 射线吸收精细结构（XAFS）表征证实了 TiO@C 中存在混合价态 Ti（δ = 0、2、3 和 4）。TiO@C 中的丰富表面缺陷可有效促进活性氧物种（ROS）的生成，从而实现莠去津（一种典型的农业除草剂）的高效和稳定的类芬顿催化降解。这种通过缺陷工程原位构建类芬顿催化剂的方法也适用于其他 MXene 族材料，如 VC 和 NbC。
