The anisotropy in semiconductor nanoplatelets (NPLs) is reflected in the anisotropy of their crystal structure and organic ligand shell, which can be used for creating new semiconductor heterostructures. This work demonstrates the synthesis of core/shell NPLs containing zero-dimensional (0D) Cd x Hg1–x Se domains embedded in CdSe NPLs via cation exchange. The strategy is based on the different accessibility of definite regions of the NPLs for incoming cations upon time-limited reaction conditions. The obtained heterostructures were successfully overcoated with a Cd y Zn1–y S shell preserving their two-dimensional (2D) morphology. The NPLs exhibit bright photoluminescence in the range of 700–1100 nm with quantum yields up to 55%, thus making them a prospective material for light-emitting applications in the near-infrared spectral range.

Metal-organic frameworks (MOFs) have attracted increasing interest for broad applications in catalysis and gas separation due to their high porosity. However, the insulating feature and the limited active sites hindered MOFs as photocathode active materials for application in photoelectrocatalytic hydrogen generation. Herein, we develop a layered conductive twodimensional conjugated MOF (2D c-MOF) comprising sp-carbon active sites based on arylene-ethynylene macrocycle ligand via CuO 4 linking, named as Cu 3 HHAE 2 . This sp-carbon 2D c-MOF displays apparent semiconducting behavior and broad light absorption till the near-infrared band (1600 nm). Due to the abundant acetylene units, the Cu 3 HHAE 2 could act as the first case of MOF photocathode for photoelectrochemical (PEC) hydrogen generation and presents a record hydrogen-evolution photocurrent density of � 260 μA cm À 2 at 0 V vs. reversible hydrogen electrode among the structurally-defined cocatalyst-free organic photocathodes.

The anion-intercalation chemistries of graphite have the potential to construct batteries with promising energy and power breakthroughs. Here, we report the use of an ultrathin, positively charged two-dimensional poly(pyridinium salt) membrane (C2DP) as the graphite electrode skin to overcome the critical durability problem. Large-area C2DP enables the conformal coating on the graphite electrode, remarkably alleviating the electrolyte. Meanwhile, the dense face-on oriented single crystals with ultrathin thickness and cationic backbones allow C2DP with high anion-transport capability and selectivity. Such desirable anion-transport properties of C2DP prevent the cation/solvent co-intercalation into the graphite electrode and suppress the consequent structure collapse. An impressive PF6−-intercalation durability is demonstrated for the C2DP-covered graphite electrode, with capacity retention of 92.8% after 1000 cycles at 1 C and Coulombic efficiencies of > 99%. The feasibility of constructing artificial ion-regulating electrode skins with precisely customized two-dimensional polymers offers viable means to promote problematic battery chemistries.

The large cell volume changes of switchable metal-organic frameworks (MOFs) render them as promising functional materials. Low-frequency phonon modes are known to influence the dynamic response of these materials. The...

Metallorganische Gerüstverbindungen (englisch metal–organic frameworks, MOFs) sind aufgrund ihrer hohen Porosität von großem Interesse für eine Vielzahl von Anwendungen in der Katalyse und Gastrennung. Eine begrenzte Anzahl an aktiven Zentren sowie das Verhalten als elektrischer Isolator machen den Einsatz von MOFs als aktives Photokathodenmaterial für die photoelektrokatalytische Wasserstoffproduktion allerdings nicht möglich. Wir berichten hiermit von der Entwicklung eines gestapelten, leitfähigen, zweidimensional‐konjugierten MOFs (englisch 2D conjugated MOF, 2D c‐MOF) welches aktive sp‐Kohlenstoffzentren enthält. Der MOF Cu3HHAE2 basiert auf einem makrozyklischen Aryl‐Alkin Liganden, welcher via CuO4 Einheiten verknüpft ist. Dieser sp‐Kohlenstoff haltige 2D c‐MOF zeigt Halbleitereigenschaften und eine breite Absorption bis in den nah‐infraroten Bereich (1600 nm). Erstmalig kann dank der hohen Anzahl an Dreifachbindungen Cu3HHAE2 als MOF‐Photokathode für die photoelektrochemische (PEC) Wasserstoffentwicklung verwendet werden. Verglichen mit anderen strukturell definierten, co‐Katalysator freien organischen Photokathoden, zeigt er eine Rekordphotostromdichte für die Wasserstoffentwicklung von ≈260 μA cm−2 bei 0 V gegen die reversible Wasserstoffelektrode (englisch reversible hydrogen electrode RHE).