Ni-Nanocluster Modified Black TiO2 with Dual Active Sites for Selective Photocatalytic CO2 Reduction

5 years ago

Ni-Nanocluster Modified Black TiO2 with Dual Active Sites for Selective Photocatalytic CO2 Reduction

Kuei-Hsien Chen, Putikam Raghunath, Tadesse Billo, Jyh-Fu Lee, Fang-Yu Fu, Li-Chyong Chen, Jih-Shang Hwang, Chih-I Wu, Kuo-You Huang, Ting-Shan Chan, Chih-Hao Lee, Hsiang-Ting Lien, Indrajit Shown, M. C. Lin, Tzu-Hsien Shen, Wei-Fu Chen

One of the key challenges in artificial photosynthesis is to design a photocatalyst that can bind and activate the CO2 molecule with the smallest possible activation energy and produce selective hydrocarbon products. In this contribution, a combined experimental and computational study on Ni-nanocluster loaded black TiO2 (Ni/TiO2[Vo]) with built-in dual active sites for selective photocatalytic CO2 conversion is reported. The findings reveal that the synergistic effects of deliberately induced Ni nanoclusters and oxygen vacancies provide (1) energetically stable CO2 binding sites with the lowest activation energy (0.08 eV), (2) highly reactive sites, (3) a fast electron transfer pathway, and (4) enhanced light harvesting by lowering the bandgap. The Ni/TiO2[Vo] photocatalyst has demonstrated highly selective and enhanced photocatalytic activity of more than 18 times higher solar fuel production than the commercial TiO2 (P-25). An insight into the mechanisms of interfacial charge transfer and product formation is explored. Black titania incorporated with dual reactive sites (Ni-nanocluster and oxygen vacancy) converts carbon dioxide selectively into acetaldehyde with sunlight and water. The enhancement in photocatalytic activity and product selectivity is attributed to the synergistic effect of the two active sites which alter the optical, electrical, and chemical properties of the black TiO2.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/smll.201702928