2 research outputs found
Electron Crystallography Reveals Atomic Structures of Metal–Organic Nanoplates with M<sub>12</sub>(μ<sub>3</sub>‑O)<sub>8</sub>(μ<sub>3</sub>‑OH)<sub>8</sub>(μ<sub>2</sub>‑OH)<sub>6</sub> (M = Zr, Hf) Secondary Building Units
Nanoscale
metal–organic frameworks (nMOFs) have shown tremendous
potential in cancer therapy and biomedical imaging. However, their
small dimensions present a significant challenge in structure determination
by single-crystal X-ray crystallography. We report here the structural
determination of nMOFs by rotation electron diffraction (RED). Two
isostructural Zr- and Hf-based nMOFs with linear biphenyldicarboxylate
(BPDC) or bipyridinedicarboxylate (BPYDC) linkers are stable under
intense electron beams to allow the collection of high-quality RED
data, which reveal a MOF structure with M<sub>12</sub>(μ<sub>3</sub>-O)<sub>8</sub>(μ<sub>3</sub>-OH)<sub>8</sub>(μ<sub>2</sub>-OH)<sub>6</sub> (M = Zr, Hf) secondary building units (SBUs).
The nMOF structures differ significantly from their UiO bulk counterparts
with M<sub>6</sub>(μ<sub>3</sub>-O)<sub>4</sub>(μ<sub>3</sub>-OH)<sub>4</sub> SBUs and provide the foundation for clarifying
the structures of a series of previously reported nMOFs with significant
potential in cancer therapy and biological imaging. Our work clearly
demonstrates the power of RED in determining nMOF structures and elucidating
the formation mechanism of distinct nMOF morphologies
Highly Active Hydrogen Evolution Electrodes via Co-Deposition of Platinum and Polyoxometalates
A highly active hydrogen evolution
reaction (HER) electrode with
low Pt loading on glassy carbon (GC) has been prepared by anodic platinum
dissolution and co-deposition of polyoxometalates. TEM, EDS, XPS,
CV, and ICP-MS analyses gave a Pt loading of 50–100 ng/cm<sup>2</sup>, corresponding to a Pt coverage of only 0.08–0.16
monolayer. With an overpotential of 65 mV at 20 mA/cm<sup>2</sup>,
the modified GC has a HER activity comparable to that of the commercial
Pt working electrode