We present a one-pot colloidal route to synthesize VSe2, a new type of metallic single-layer nanosheet. The ∼0.4 nm thick VSe2 single-layer nanosheets possess extraordinary electrocatalytic hydrogen evolution reaction (HER) performance with a low onset overpotential of 108 mV, a small Tafel slope of 88 mV per decade, and an exceptional overpotential of 206 mV at a current density of 10 mA cm(-2).

Higher-voltage operation is crucial to increase the energy density of rechargeable batteries. Here we explored the Cr 4+ /Cr 3+ redox couple in a polyanion framework for a high-voltage sodium battery cathode. An archetypal NASICON-phase Na 3 Cr 2 (PO 4 ) 3 exhibited a reversible redox activity at ca. 4.5 V versus Na/Na + , offering further scope for searching new high-voltage materials based on Cr 4+ /Cr 3+ redox couple.

Stoichiometric LiMnO2 and NaMnO2 with a cation-disordered rocksalt-type structure as metastable polymorphs were successfully prepared by mechanical milling.

3-Phenylthiophene-based water-soluble copolythiophenes (CPT1) were designed for colorimetric and fluorometric detection of lipopolysaccharide (LPS). The sensor (CPT1-C) shows a high selectivity to LPS in the presence of other negatively charged bioanalytes as well an extreme sensitivity with the detection limit at picomolar level, which is the lowest ever achieved among all synthetic LPS sensors available thus far. Significantly, the sensing interaction can be apparently observed by the naked eyes, which presents a great advantage for its practical applications. The appealing performance of sensor was demonstrated to originate from the multiple electrostatic and hydrophobic cooperative interactions, synergetic with signal amplification via the conformational change of the 3-phenylthiophene-based copolymer main chain. As a straightforward application, CPT1-C is capable of rapidly discriminating the Gram-negative bacteria (with LPS in the membrane) from Gram-positive bacteria (without LPS).