Kavun V, Uslamin E, van der Linden B, Canossa S, Goryachev A, Bos EE, Garcia Santaclara J, Smolentsev G, Repo E, van der Veen MA. Promoting Photocatalytic Activity of NH
2-MIL-125(Ti) for H
2 Evolution Reaction through Creation of Ti
III- and Co
I-Based Proton Reduction Sites.
ACS Appl Mater Interfaces 2023;
15:54590-54601. [PMID:
37966899 PMCID:
PMC10694822 DOI:
10.1021/acsami.3c15490]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 11/17/2023]
Abstract
Titanium-based metal-organic framework, NH2-MIL-125(Ti), has been widely investigated for photocatalytic applications but has low activity in the hydrogen evolution reaction (HER). In this work, we show a one-step low-cost postmodification of NH2-MIL-125(Ti) via impregnation of Co(NO3)2. The resulting Co@NH2-MIL-125(Ti) with embedded single-site CoII species, confirmed by XPS and XAS measurements, shows enhanced activity under visible light exposure. The increased H2 production is likely triggered by the presence of active CoI transient sites detected upon collection of pump-flow-probe XANES spectra. Furthermore, both photocatalysts demonstrated a drastic increase in HER performance after consecutive reuse while maintaining their structural integrity and consistent H2 production. Via thorough characterization, we revealed two mechanisms for the formation of highly active proton reduction sites: nondestructive linker elimination resulting in coordinatively unsaturated Ti sites and restructuring of single CoII sites. Overall, this straightforward manner of confinement of CoII cocatalysts within NH2-MIL-125(Ti) offers a highly stable visible-light-responsive photocatalyst.
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