General Strategy to Prepare Nondoped Circularly Polarized Luminescent Liquid Crystal Materials with Tunable Performance.

Chiral luminescent liquid crystals have attracted widespread attention from researchers due to their unique advantages in constructing circularly polarized luminescent (CPL) materials with large luminescent asymmetry factor (glum) values. However, how to effectively prepare nondoped CPL chiral liquid crystals remains a challenge. In this article, we developed an effective and universal method to prepare nondoped CPL chiral liquid crystal materials. To achieve our strategy, we copolymerized chiral monomer M0Mt with α-cyanostilbene-based luminescent monomers MmPVPCN (m = 6, 8, 10) bearing different flexible spacer lengths to obtain a series of CPL chiral liquid crystal copolymers poly(MmPVPCN(x)-co-M0Mt(y)). Under the induction of the chiral component, the α-cyanostilbene component assembles to form chiral liquid crystals. Meanwhile, α-cyanostilbene also exhibits aggregation-induced emission enhancement characteristics. Therefore, with the help of the selective reflection effect of chiral liquid crystals, the copolymer films can emit efficient CPL. For poly(M8PVPCN(0.85)-co-M0Mt(0.15)), the glum and solid luminescence quantum yield can achieve -2.61 × 10-2 and 25.04%, respectively. In addition, by altering the chemical structure of the copolymers, the phase structure of the copolymers can be effectively controlled, thereby regulating their CPL properties.

Polymetallic sulfide nanosheet arrays with composite structure as a highly efficient oxygen evolution electrocatalyst.

Designing an earth-abundant and cost-effective electrocatalyst for oxygen evolution reaction (OER) is the crux to the hydrogen production by water electrolysis on industrial scale. Herein, we developed a trimetallic sulfide hybrid of CoS1.097/Fe1-xS/Ni3S2/NF nanoarrays by the combination of morphology optimization and interface modulation. The unique morphology of ultrathin nanosheets significantly enriches the reaction sites of the catalyst, while the abundant heterogeneous interfaces effectively regulate the local electron structure and thus intrinsically enhances the catalytic activity of the material. As a result, the catalyst delivers the superior OER performance with the ultralow overpotential of 229 mV at the current density of 50 mA cm-2 and Tafel slope of 30.2 mV dec-1. Furthermore, the current density of the material keeps constant for 50 h in 1.0 M KOH. This work proposes a strategy for the synthesis of polymetallic sulfide catalysts with composite structure as an efficient OER catalyst by morphology optimization and interface modulation.