在高度稳定的卟啉金属-有机骨架中原位封装石墨烯量子点用于高效光催化 CO 还原。

In Situ Encapsulation of Graphene Quantum Dots in Highly Stable Porphyrin Metal-Organic Frameworks for Efficient Photocatalytic CO Reduction.

机构信息

Institute of Functional Porous Materials, School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.

Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou 510632, China.

出版信息

Molecules. 2023 Jun 12;28(12):4703. doi: 10.3390/molecules28124703.

DOI:10.3390/molecules28124703

PMID:37375258

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10303723/

Abstract

Photocatalytic CO reduction to valuable hydrocarbon solar fuel is of great significance but still challenging. Strong CO enrichment ability and easily adjustable structures make metal-organic frameworks (MOFs) potential photocatalysts for CO conversion. Even though pure MOFs have the potential for photoreduction of CO, the efficiency is still quite low due to rapid photogenerated electron-hole recombination and other drawbacks. In this work, graphene quantum dots (GQDs) were in situ encapsulated into highly stable MOFs via a solvothermal method for this challenging task. The GQDs@PCN-222 with encapsulated GQDs showed similar Powder X-ray Diffraction (PXRD) patterns to PCN-222, indicating the retained structure. The porous structure was also retained with a Brunauer-Emmett-Teller (BET) surface area of 2066 m/g. After incorporation of GQDs, the shape of GQDs@PCN-222 particles remained, as revealed by the scanning electron microscope (SEM). As most of the GQDs were covered by thick PCN-222, it was hard to observe those GQDs using a transmission electron microscope (TEM) and a high-resolution transmission electron microscope (HRTEM) directly, the treatment of digested GQDs@PCN-222 particles by immersion in a 1 mM aqueous KOH solution can make the incorporated GQDs visible in TEM and HRTEM. The linker, deep purple porphyrins, make MOFs a highly visible light harvester up to 800 nm. The introduction of GQDs inside PCN-222 can effectively promote the spatial separation of the photogenerated electron-hole pairs during the photocatalytic process, which was proved by the transient photocurrent plot and photoluminescence emission spectra. Compared with pure PCN-222, the obtained GQDs@PCN-222 displayed dramatically enhanced CO production derived from CO photoreduction with 147.8 μmol/g/h in a 10 h period under visible light irradiation with triethanolamine (TEOA) as a sacrificial agent. This study demonstrated that the combination of GQDs and high light absorption MOFs provides a new platform for photocatalytic CO reduction.

摘要

光催化 CO 还原为有价值的碳氢化合物太阳能燃料具有重要意义，但仍然具有挑战性。金属有机骨架（MOFs）具有较强的 CO 富集能力和易于调节的结构，是 CO 转化的潜在光催化剂。尽管纯 MOFs 具有 CO 光还原的潜力，但由于光生电子-空穴复合迅速等缺点，其效率仍然相当低。在这项工作中，通过溶剂热法将石墨烯量子点（GQDs）原位封装到高度稳定的 MOFs 中，以解决这一具有挑战性的任务。与 PCN-222 相比，封装 GQDs 的 GQDs@PCN-222 具有相似的粉末 X 射线衍射（PXRD）图谱，表明其结构得以保留。BET 表面积为 2066 m/g，表明多孔结构得以保留。扫描电子显微镜（SEM）显示，GQDs@PCN-222 颗粒的形状保持不变。由于大部分 GQDs 被厚厚的 PCN-222 覆盖，因此很难直接用透射电子显微镜（TEM）和高分辨率透射电子显微镜（HRTEM）观察到那些 GQDs，通过将消化后的 GQDs@PCN-222 颗粒浸泡在 1 mM 水溶液中，可以使 T 中掺入的 GQDs 在 EM 和 HRTEM 中可见。连接体，深紫色卟啉，使 MOFs 成为高达 800nm 的高光捕获器。GQDs 引入 PCN-222 内部可以在光催化过程中有效促进光生电子-空穴对的空间分离，这一点通过瞬态光电流图和光致发光发射光谱得到了证明。与纯 PCN-222 相比，在可见光照射下，以三乙醇胺（TEOA）为牺牲剂，在 10 小时内，获得的 GQDs@PCN-222 的 CO 光还原产物的 CO 生成量显著提高，达到 147.8 μmol/g/h。该研究表明，GQDs 和高光吸收 MOFs 的结合为光催化 CO 还原提供了一个新的平台。