Li Shumin, Ji Kang, Zhang Meng, He Cangshuang, Wang Jin, Li Zhengquan
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Zhejiang Normal University, Jinhua, Zhejiang 321004, P. R. China.
Nanoscale. 2020 May 7;12(17):9533-9540. doi: 10.1039/d0nr01696a.
Photocatalytic CO2 reduction is a promising technology to mitigate global warming and enrich energy supply. Metal-organic frameworks (MOFs) are prospective photocatalysts for CO2 reduction, but severe charge recombination and limited visible light response largely restrain their applications. As carbon dots (CDs) can act as both electron receptors and photosensitizers, here we propose to develop CD-hybridized MOF photocatalysts for improving their activity for CO2 reduction. In particular, because of the small size of CDs, we have managed to encapsulate CDs inside MOF particles and found that these CD@MOFs exhibit hugely improved photocatalytic activity compared with CD-decorated MOFs or pristine MOFs. Our investigations suggest that placing small CD cocatalysts near the internal metal-oxo clusters of MOFs can help efficient charge transfer and separation in the hybrid photocatalysts, due to the formation of many small heterojunctions among MOFs. The developed CD-hybridized MOF catalysts are characterized in detail and their working mechanism is explored. This work may demonstrate a novel strategy to develop MOF-based hybrid photocatalysts with enhanced photocatalytic activity.
光催化二氧化碳还原是一项缓解全球变暖并丰富能源供应的很有前景的技术。金属有机框架材料（MOFs）是用于二氧化碳还原的有前景的光催化剂，但严重的电荷复合和有限的可见光响应在很大程度上限制了它们的应用。由于碳点（CDs）既可以作为电子受体又可以作为光敏剂，在此我们提议开发碳点杂化的MOF光催化剂以提高其二氧化碳还原活性。特别地，由于碳点尺寸小，我们成功地将碳点封装在MOF颗粒内部，并且发现这些CD@MOFs与碳点修饰的MOFs或原始MOFs相比表现出大幅提高的光催化活性。我们的研究表明，由于在MOFs中形成了许多小的异质结，将小的碳点助催化剂放置在MOFs的内部金属氧簇附近有助于杂化光催化剂中的有效电荷转移和分离。对所开发的碳点杂化MOF催化剂进行了详细表征并探索了其工作机制。这项工作可能展示了一种开发具有增强光催化活性的基于MOF的杂化光催化剂的新策略。
