Mesostructured silica MCM-41 has been one of the most extensively studied mesostructured materials since its first synthesis by Mobil scientists in 1992.[1] Many important applications [2] of mesostructured silica MCM-41 in catalysis, separation, and nanoengineering are closely correlated to its ordered two-dimensional (2D) hexagonal mesostructure/ mesopore. Besides the usual straight 2D hexagonal mesostructure, [3] various curved mesostructures of MCM-41 have also been reported by several research groups in the last decade, [4] which has aroused great academic interest in their enigmatic morphogenesis. Recently our research group has investigated the topological transformation of a series of vesicular MCM-41 compounds with different mesostructures in an alkaline synthesis system [5] that was initialy developed by Rathouský and co-workers.[6] The self-assembly of sodium silicate (SS) and cetyltrimethylammonium bromide (CTAB) into a hexagonal mesostructure in such a method is driven by the hydrolysis of ethyl acetate (EA). Herein we report that chiral mesostructured silica nanofibers of MCM-41 can be fabricated in this SS/CTAB/EA/H 2 O system by simply lowering the SS and CTAB concentrations below 0.5 mol per 1000 mol H 2 O. It is remarkable that two types of chiral mesostructures with different symmetries were synthesized from the usual achiral materials in this study. Moreover, a relationship between the chiral and ordinary achiral mesostructures of MCM-41 was revealed through a systematic investigation of the synthesis system.The first type of chiral nanofibers of MCM-41 (Figure 1 a, b) has a single twist axis. The XRD pattern of such a single-axis nanofiber (Figure 1 c) reveals a highly ordered 2D hexagonal mesostructure with a lattice constant of 4.5 nm. The N 2 sorption isotherms of the calcined product show a steep capillary condensation at a P/P 0 ratio of 0.2:1-0.3:1, which corresponds to a BJH pore size of 2.4 nm (Figure 1 d). The BET surface area and mesopore volume of the single-axis nanofiber are 960 m 2 g À1 and 0.63 cm 3 g À1 , respectively. Analysis of the chiral mesostructure of the single-axis nanofibers by electron microscopy showed: 1) The twisted crystal facets could be distinguished from their field-emission SEM images (see Supporting Information); 2) periodic fringes along the axis of the nanofiber in the TEM image (Figure 1 b); and 3) the observed fringes moved along the axis when the

 ε 100 C of 4-10%, as well as thermal stability below 500 °C, [9,10,14-17] which can hardly satisfy the requirements of Low-cost and large-area solar-thermal absorbers with superior spectral selectivity and excellent thermal stability are vital for efficient and large-scale solar-thermal conversion applications, such as space heating, desalination, ice mitigation, photothermal catalysis, and concentrating solar power. Few state-of-the-art selective absorbers are qualified for both low-(<200 °C) and high-temperature (>600 °C) applications due to insufficient spectral selectivity or thermal stability over a wide temperature range. Here, a high-performance plasmonic metamaterial selective absorber is developed by facile solutionbased processes via assembling an ultrathin (≈120 nm) titanium nitride (TiN) nanoparticle film on a TiN mirror. Enabled by the synergetic in-plane plasmon and out-of-plane Fabry-Pérot resonances, the all-ceramic plasmonic metamaterial simultaneously achieves high, full-spectrum solar absorption (95%), low mid-IR emission (3% at 100 °C), and excellent stability over a temperature range of 100-727 °C, even outperforming most vacuum-deposited absorbers at their specific operating temperatures. The competitive performance of the solution-processed absorber is accompanied by a significant cost reduction compared with vacuum-deposited absorbers. All these merits render it a cost-effective, universal solution to offering high efficiency (89-93%) for both low-and high-temperature solar-thermal applications.

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High graphite N content in nitrogen-doped graphene is synthesized by a one-step hydrothermal reaction, which can catalyze the reduction of nitroarenes by using a small amount of NaBH4 in water with high yield.

The mixed perovskite (FAPbI3)1−x(MAPbBr3)x, prepared by directly mixing different perovskite components, suffers from phase competition and a low‐crystallinity character, resulting in instability, despite the high efficiency. In this study, a dual ion exchange (DIE) method is developed by treating as‐prepared FAPbI3 with methylammonium brodide (MABr)/tert‐butanol solution. The converted perovskite thin film shows an optimized absorption edge at 800 nm after reaction time control, and the high crystallinity can be preserved after MABr incorporation. More importantly, it is found that the threshold electrical field to initiate ion migration is greatly increased in DIE perovskite thin film because excess MABr on the surface can effectively heal structural defects located on grain boundaries during the ion exchange process. It contributes to the over‐one‐month moisture stability under ≈65% room humidity (RH) and greatly enhanced light stability for the bare perovskite film. As a result of preserved high crystallinity and simultaneous grain boundary passivation, the perovskite solar cells fabricated by the DIE method demonstrate reliable reproducibility with an average power conversion efficiency (PCE) of 17% and a maximum PCE of 18.1%, with negligible hysteresis.

There has been increasing interest in the emerging ionic thermoelectric materials with huge ionic thermopower. However, it’s challenging to selectively tune the thermopower of all-solid-state polymer materials because the transportation of ions in all-solid-state polymers is much more complex than those of liquid-dominated gels. Herein, this work provides all-solid-state polymer materials with a wide tunable thermopower range (+20~−6 mV K−1), which is different from previously reported gels. Moreover, the mechanism of p-n conversion in all-solid-state ionic thermoelectric polymer material at the atomic scale was presented based on the analysis of Eastman entropy changes by molecular dynamics simulation, which provides a general strategy for tuning ionic thermopower and is beneficial to understand the fundamental mechanism of the p-n conversion. Furthermore, a self-powered ionic thermoelectric thermal sensor fabricated by the developed p- and n-type polymers demonstrated high sensitivity and durability, extending the application of ionic thermoelectric materials.

Plasmonic nanoantennas (PNs) comprised of film-coupled or in-plane coupled nanoparticles have been exploited for light confinement or field enhancement. However, achieving strong local electric field enhancements (|E loc|/|E 0| > 100) and near-perfect absorption (>95%) simultaneously remains a challenge, although it will benefit a wide range of applications. Here Ag/Al2O3/Au PNs are proposed by introducing high-density triangular nanodisks into film-coupled systems, which can produce dense “hot spots” with a large |E loc|/|E 0| of 211 and a near-unity absorbance. Due to the combination of the strong lightning rod effect and the out-of-plane coupling, the MIM structure combined with the triangular nanodisks effectively enhances the coupling strength and thereby the electric field confinements along the x-, y-, and z-directions in film-coupled PNs, showing a lateral resolution as small as 4 nm. The highest |E loc|/|E 0| is more than three times higher than for their circular and square counterparts and more than four times higher than for isolated triangular nanodisks. The near-perfect absorption results from the magnetic resonance induced by plasmonic coupling. Compared to the bowtie-shaped PNs based on the in-plane coupling, the developed PNs here offer more desired advantages including the polarization-independent near-perfect absorption, much larger field enhancements, and greater potential for large-scale production.