College of Ecology and Environment, Chengdu University of Technology, Chengdu, 610059, China.
College of Material and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu, 610059, China.
Environ Sci Pollut Res Int. 2022 Mar;29(11):16449-16459. doi: 10.1007/s11356-021-15340-0. Epub 2021 Oct 14.
Graphitic carbon nitride (g-CN) has attracted growing attention recently for photodegradation of pollutants. However, the photosensitization performance of g-CN was limited by insufficient generation efficiency of reactive oxygen species (ROS) and weak light absorption. In this study, platinum (Pt)-doped g-CN photocatalyst was synthesized by thermal polycondensation using dicyandiamide and chloroplatinic acid. The structure and composition of Pt-doped g-CN were tested by scanning electron microscope (SEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-mass spectrometry (ICP-MS), which indicated that the Pt-doped g-CN was successfully prepared. Compared with bare g-CN, Pt-doped g-CN has wider light absorption range, lower band gap, and higher photon-generated carrier migration efficiency, which significantly improved the light absorption range and photosensitization efficiency of Pt-doped g-CN, while photodegradation efficiency for Rhodamine B (RhB) increased from 50 to 90%. The effecting factors of adsorption and photocatalytic degradation performance of Pt-doped g-CN for RhB were investigated in detail. The adsorption is a monolayer adsorption process that fits the Langmuir model, as well as being a spontaneous endothermic process. Using a white LED as an excitation source, electrons and holes in Pt-doped g-CN were generated. The electrons reacting with dissolved oxygen produce active oxygen species such as •OH and O, which can degrade RhB on the surface of Pt-doped g-CN. The photocatalytic method has the advantages of simple operation, low cost, and high efficiency, and has the potential to directly remove dyes in wastewater utilizing sunlight.
石墨相氮化碳（g-CN）因其对污染物的光降解性能而受到越来越多的关注。然而，g-CN 的光敏化性能受到活性氧（ROS）生成效率不足和弱光吸收的限制。在这项研究中，通过使用双氰胺和氯铂酸的热缩聚合成了掺铂 g-CN 光催化剂。通过扫描电子显微镜（SEM）、X 射线衍射仪（XRD）、X 射线光电子能谱（XPS）和电感耦合等离子体质谱（ICP-MS）对 Pt 掺杂 g-CN 的结构和组成进行了测试，结果表明成功制备了 Pt 掺杂 g-CN。与裸 g-CN 相比，Pt 掺杂 g-CN 具有更宽的光吸收范围、更低的带隙和更高的光生载流子迁移效率，这显著提高了 Pt 掺杂 g-CN 的光吸收范围和光敏化效率，同时 Rhodamine B（RhB）的光降解效率从 50%提高到 90%。详细研究了 Pt 掺杂 g-CN 对 RhB 的吸附和光催化降解性能的影响因素。吸附是一个单层吸附过程，符合 Langmuir 模型，也是一个自发的吸热过程。使用白色 LED 作为激发源，Pt 掺杂 g-CN 中的电子和空穴被激发。电子与溶解氧反应产生•OH 和 O 等活性氧物质，可降解 Pt 掺杂 g-CN 表面的 RhB。该光催化方法具有操作简单、成本低、效率高的优点，并且具有利用太阳光直接去除废水中染料的潜力。
