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Halide double perovskites have emerged as remarkable semiconductors owing to their nontoxicity and superior optoelectronic features. Despite recent exciting progress, halide double perovskites with...

We have designed and synthesized a series of two-dimensional materials featuring with a (3,6)-connected kgd layer, in which an unprecedented anionic Cu6I7– cluster was first trapped through a cation-induced synthetic strategy. The emission colors of these cluster-based luminophores gradually shift from blue to yellow as the monovalent cations (Li+, Na+, NH4+, K+, TEA+) located between the neighboring layers changed. SCXRD analyses discover that the variation of the emission may be attributed to the transformation of the hourglass-shaped Cu6I7– cluster. The bright, tunable, and broad luminescent emissions make them promising candidates as phosphors for light-emitting diodes (LEDs). Particularly, compound 1-TEA emitting intensive yellow light with high luminescence quantum efficiency (QY = 79.9%) shows extremely high thermal, pH, organic solvent, and mechanical photostabilities. By employing it as a yellow phosphor, we fabricate a series of white lighting materials with high color rendering index (CRI).

Developing superior deep-ultraviolet (deep-UV) nonlinear optical (NLO) materials is a great challenge because of the contradiction between deep-UV transparency and enhanced second harmonic generation (SHG), especially for deep-UV NLO phosphates in which the constituent P–O groups have relatively small microscopic SHG coefficients. Here we report a new noncentrosymmetric phosphate Cs2LiPO4 (I), whose crystal structure consists of [LiPO4]∞ layered structural units with a novel honeycomb-like topology. As compared with the benchmark deep-UV NLO material KBe2BO3F2, I is beryllium-free, and it is relatively easy to grow its large single crystals because of its congruent melting. Furthermore, it not only is deep-UV transparent but also exhibits an unexpectedly enhanced SHG response of 1.8 × KH2PO4 that hits a new high in deep-UV NLO phosphates. These results demonstrate that I satisfies the key requirements of being a promising deep-UV NLO candidate. Theory calculations and structural analysis reveal that the e...

A series of hybrids of nitrogen-doped graphitic porous carbon and carbon nanotubes (NGPC/NCNTs) are readily prepared in a stepwise manner by using a typical metal–organic framework (MOF-5) and urea as the carbon and nitrogen precursors, and nickel as the graphitization catalyst, respectively. These NGPC/NCNTs hybrids have demonstrated prominent catalytic activities toward oxygen reduction reaction (ORR) in alkaline medium. Compared to the benchmark Pt/C catalyst, the optimized NGPC/NCNT-900 (annealed at 900 °C) exhibits superior catalytic activity, durability and methanol tolerance, which makes it one of the best ORR electrocatalysts derived from MOFs. The promising properties in NGPC/NCNT-900 are mainly attributed to synergistic contributions of its unique hybrid structure, rich nitrogen doping, high graphitic degree, and large surface area. This attractive route for the preparation of NGPC/NCNTs holds promise for general use of a great number of available and yet rapidly growing MOFs in constructing hig...

Highly controllable photoelectric switches are urgently demanded in the field of nonlinear optics. In the present work, high-performance quadratic molecular nonlinear optical (NLO)-switches based on organic hydrogen-bonded ferroelectric materials, showing large contrasts (up to ∼68%), tunable reversibility, and superior switching “on–off” time, were first prepared from the highly oriented thin polymer films, which overcome the stability problems of the conventional photochromic counterparts and throw light on the further research of NLO-switching materials from the emerging field of organic molecular ferroelectrics.