High-current
density (≥1 A cm–2) is a
critical factor for large-scale industrial application of water-splitting
electrocatalysts, especially seawater-splitting. However, it still
remains a great challenge to reach high-current density due to the
lack of active and stable intrinsic catalytic active sites in catalysts.
Herein, we report an original three-dimensional self-supporting graphdiyne/molybdenum
oxide (GDY/MoO3) material for efficient hydrogen evolution
reaction via a rational design of “sp C–O–Mo
hybridization” on the interface. The “sp C–O–Mo
hybridization” creates new intrinsic catalytic active sites
(nonoxygen vacancy sites) and increases the amount of active sites
(eight times higher than pure MoO3). The “sp C–O–Mo
hybridization” facilitates charge transfer and boosts the dissociation
process of H2O molecules, leading to outstanding HER activity
with high-current density (>1.2 A cm–2) in alkaline
electrolyte and a decent activity and stability in natural seawater.
Our results show that high-current density electrocatalysts can be
achieved by interfacial chemical bond engineering, three-dimensional
structure design, and hydrophilicity optimization.
It is very challenging to introduce azaborine into an electron-deficient arene system because of unfavorable intramolecular electrophilic borylation reaction. In this report, we adopted a straightforward methodology to construct a large BN-embedded π-system based on perylene diimide (PDI), which is the first BN-annulation example with highly electron-withdrawing polycyclic aromatic hydrocarbons. The physical properties of the as-prepared N,N-dicyclohexyl-1-aza-12-bora-benzoperylene diimide (PDI-1BN) have been fully studied, and its sensing behavior to fluoride ion as well as its OLED performance was also investigated.
Replacing the CH groups in the backbones of acenes with heteroatoms offers scientists greater opportunities to tune their properties, as the type, position, number, and the valence of the introduced heteroatoms have strong effects on the frontier orbital energy levels. When the heteroatoms are nitrogen atoms, all of the resulting materials are called azaacenes. Recently, the synthesis, structure, physical properties, and applications of azaacene derivatives have been intensively investigated. This review focuses on recent synthetic efforts (since 2013) toward making novel azaacenes as well as their potential applications beyond field-effect transistors (FETs) including organic light-emitting diodes (OLEDs), memory devices, phototransistors, solar cells, photoelectrical chemical cells, sensors, and conductors.
Micellization of poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG114-b-P4VP61) induced by 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin (TPPS) in acidic solutions were studied by dynamic and static light scattering, atomic force microscope, and UV-vis spectroscopy. The resultant complex micelles had a core-shell structure with the electrostatically complex TPPS/P4VP as the core and the soluble PEG as the shell. The anionic TPPS in the micellar core formed J-aggregates at pH 1.5-2.5 and H-aggregates at pH 3.0-4.0, respectively. Interconversion between the J-aggregates and the H-aggregates was carried out by adjusting the pH value of the micelle solutions. It is worth noting that the micelles showed strong split Cotton effect in the circular dichroism spectra although TPPS and the copolymer were all achiral. The resulting chirality sign could be selected by the hydrodynamic forces of a stirring vortex. Positive or negative chiral signals appeared when stirring clockwise or anticlockwise.
The synthesis and sensing characteristics of a new class of colorimetric and fluorometric dual-modal probe for mercury ion are outlined. Judicious placement of two dithia-dioxa-aza macrocycles on the BODIPY chromophore generates this interesting molecule. A highly Hg2+-selective fluorescence enhancing property (>7-fold) in conjunction with a visible colorimetric change from purple to red-pink can be observed, leading to potential fabrication of both "naked-eye" and ratiometric fluorescent detection of Hg2+.
A novel fluorescent probe that possess both BODIPY and Rhodamine moieties has been designed for the selective detection of Hg(2+) and Ba(2+) ions on the controlling by a logic gate. The characteristic fluorescence of the Ba(2+)-selective OFF-ON and the Hg(2+)-selective fluorescence bathochromic shift can be observed, and the concept has been used to construct a combinational logic circuit at the molecular level. These results will be useful for further molecular design to mimic the function of the complex logic gates on controlling.
Graphdiyne (GDY), a novel two-dimensional full-carbon material, has attracted lots of attention because of its high conjugated system comprising sp and sp-hybridized carbons. The distinctive structure characteristics endow it unique electronic structure, uniform distributed pores and excellent chemical stability. A novel GDY-supported NiFe layered double hydroxide (LDH) composite was successfully prepared for the first time. By taking advantage of the increased surface active areas and improved conductivity, the designed hierarchical GDY@NiFe composite exhibits outstanding catalytic activity that only required a small overpotential about 260 mV to achieve the current density of 10 mA cm. The nanocomposite shows excellent durability in alkaline medium implying a superior OER electrocatalytic activity. It is anticipated that the as-prepared GDY@NiFe composite electrocatalyst provide new insights in designing graphdiyne-supported electrocatalyst materials for oxygen evolution application.
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