Enabling Visible‐Light‐Driven Selective CO2 Reduction by Doping Quantum Dots: Trapping Electrons and Suppressing H2 Evolution

• Published in: Angewandte Chemie International Edition Vol. 57; no. 50; pp. 16447 - 16451
• Main Authors: Wang, Jin, Xia, Tong, Wang, Lei, Zheng, Xusheng, Qi, Zeming, Gao, Chao, Zhu, Junfa, Li, Zhengquan, Xu, Hangxun, Xiong, Yujie
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 10.12.2018
• Edition: International ed. in English
• Subjects: Active sites; Cadmium sulfide; Carbon dioxide; Catalysis; Catalytic activity; catalytic sites; Cations; CO2 reduction; Coordination compounds; Doping; Durability; Electrons; Harvesting; Hydrogen evolution; Metal complexes; Metal ions; Photocatalysis; Quantum dots; Reduction; Reduction (metal working); Selectivity; Trapping
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201810550

Quantum dots (QDs), a class of promising candidates for harvesting visible light, generally exhibit low activity and selectivity towards photocatalytic CO2 reduction. Functionalizing QDs with metal complexes (or metal cations through ligands) is a widely used strategy for improving their catalytic activity; however, the resulting systems still suffer from low selectivity and stability in CO2 reduction. Herein, we report that doping CdS QDs with transition‐metal sites can overcome these limitations and provide a system that enables highly selective photocatalytic reactions of CO2 with H2O (100 % selectivity to CO and CH4), with excellent durability over 60 h. Doping Ni sites into the CdS lattice leads to effective trapping of photoexcited electrons at surface catalytic sites and substantial suppression of H2 evolution. The method reported here can be extended to various transition‐metal sites, and offers new opportunities for exploring QD‐based earth‐abundant photocatalysts. Quantum dots (QDs), a class of promising nanoparticles for visible‐light harvesting, commonly possess low activity and selectivity towards photocatalytic CO2 reduction. Doping CdS QDs with transition‐metal cations, which can trap photoexcited electrons and suppress H2 evolution, provides an approach to visible‐light‐driven highly selective CO2 reduction with excellent durability.