Small molecule biomimetics inspired by the active site of the [FeFe]‐hydrogenase enzymes have shown promising electrocatalytic activity for hydrogen (H2) generation. However, most of the active‐site mimics based on [2Fe‐2S] clusters are not water‐soluble which limits the use of these electrocatalysts to organic media. Polymer‐supported [2Fe‐2S] systems, in particular, single‐site metallopolymer catalysts, have shown drastic improvements for electrocatalytic H2generation in aqueous milieu. [2Fe‐2S] complexes functionalized within well‐defined macromolecular supports via covalent bonding have demonstrated water solubility, enhanced site‐isolation, and improved chemical stability during catalysis. In this report, the synthesis of a new propanedithiolate (pdt)‐[2Fe‐2S] complex bearing a single α‐bromoester moiety for use in atom transfer radical polymerization (ATRP) is demonstrated as a novel metalloinitiator to prepare water‐soluble poly(2‐dimethylaminoethyl methacrylate) grafted (PDMAEMA‐
The presence of molecular monolayers on semiconductor surfaces can improve the stability of semiconductor interfaces by inhibiting the growth of native oxides and defects which affect the materials’ electronic properties. The development of catalytically active passivated interfaces on semiconductor materials presents a useful material design for value‐added product conversion. Herein, an iron‐based catalyst covalently attached to silicon (Si) is reported for the investigation of activity and electrochemical decomposition pathways of diiron hydrogenase enzyme mimics. The employed catalyst, Fe2(CO)6(µ‐S‐C6H4‐p‐OH)2([FeFe]), mimics the active sites of these enzymes. Surface modification using this catalyst passivates the interface, hindering the formation of native SiO2for more than 300 h. [FeFe] modification improves the overpotential required to produce 10 mA cm–2by 100 mV, with a hydrogen evolution rate of 2.31 × 10–5 mol h–1 cm–2 (−0.78 V versus RHE). However, structural rearrangement transpires within 1 h of electrolysis, where Fe‐S bond dissociates at the catalytic center, resulting in an aromatic linkage modified Si interface. While semiconductor−catalyst interfaces have often been reported in the literature, their decomposition pathways have received limited discussion. Herein, this Si−[FeFe] interface is used as a tool for understanding the activity and decomposition mechanisms of the attached molecular catalyst.
more » « less- NSF-PAR ID:
- 10448426
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials Interfaces
- Volume:
- 8
- Issue:
- 10
- ISSN:
- 2196-7350
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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