For VO-based thermochromic smart windows, high luminous transmittance (T) and solar regulation efficiency (ΔT) are usually pursued as the most critical issues, which have been discussed in numerous researches. However, environmental durability, which has rarely been considered, is also so vital for practical application because it determines lifetime and cycle times of smart windows. In this paper, we report novel VO@ZnO core-shell nanoparticles with ultrahigh durability as well as improved thermochromic performance. The VO@ZnO nanoparticles-based thermochromic film exhibits a robust durability that the ΔT keeps 77% (from 19.1% to 14.7%) after 10 hours in a hyperthermal and humid environment, while a relevant property of uncoated VO nanoparticles-based film badly deteriorates after 30 h. Meanwhile, compared with the uncoated VO-based film, the VO@ZnO-based film demonstrates an 11.0% increase (from 17.2% to 19.1%) in ΔT and a 31.1% increase (from 38.9% to 51.0%) in T. Such integrated thermochromic performance expresses good potential for practical application of VO-based smart windows.

Nitrogen-vacancy (NV) centers in diamond can be used as quantum sensors to image the magnetic field with nanoscale resolution. However, nanoscale electric-field mapping has not been achieved so far because of the relatively weak coupling strength between NV and electric field. Here, using individual shallow NVs, we quantitatively image electric field contours from a sharp tip of a qPlus-based atomic force microscope (AFM), and achieve a spatial resolution of ~10 nm. Through such local electric fields, we demonstrated electric control of NV’s charge state with sub-5 nm precision. This work represents the first step towards nanoscale scanning electrometry based on a single quantum sensor and may open up the possibility of quantitatively mapping local charge, electric polarization, and dielectric response in a broad spectrum of functional materials at nanoscale.

The photochromism of a CsxWO3resin coating was reduced by combining an ultraviolet absorbing agent (UVA) and a SiO2blocking layer.

1675 mA h g −1 ), low-toxicity, high natural abundance of sulfur, as well as environmental friendliness. [1][2][3][4][5] However, two major challenges closely associated with the electrolytes prevented any immediate commercialization of LSB: 1) the incessant reaction between Li-metal and electrolytes, leading to the constant growth of Li dendrite and inactive Li [6][7][8] and 2) the dissolution of the intermediate polysulfides and their subsequent shuttling. [9][10] These irreversible and parasitic processes result in fast capacity degradation, persistent loss of active materials (both Li and S), severe self-discharge and even catastrophic safety hazard. [11][12] Aiming to resolve these parasitic reactions, significant efforts have been made to develop new electrolyte formulations, including electrolyte additives [13][14][15] solvents, [16][17] and Li salts, with structures of either unsaturation or fluorination that can contribute unique interphasial chemistries to protect Li-metal or suppress polysulfide dissolution and shuttling. [18][19] Among these components, new anionic compounds (counterions of Li + in the salts) are rather rare as compared with new molecular compounds (solvents and additives), mainly due to the much higher difficulty associated with their designing and synthesis. Hence, how anions contribute to interphases remains little understood, although a few successful examples of anionderived interphases, as represented by LiBOB and LiDFOB in nonaqueous and LiTFSI in aqueous electrolytes, suggests that the protections provided by such interphases often outperform their molecular counterparts. In particular, for the interphase protecting Li-metal anode, the anion-derived interphase seems to be more effective than those formed by solvents or additives. [20][21][22][23] One challenge presented for anion-derived interphases is their negatively charged nature, which discourages their presence in the inner-Helmholtz layer at anode surface. [24] In the case of water-in-salt electrolytes (WiSE), such "anode challenge" was partially offset by superconcentration, which compresses the anions into the inner-Helmholtz layer and forces an interphasial chemistry that is otherwise impossible in diluted aqueous electrolyte. The astonishing benefit brought by such anion-derived interphase is an electrochemical stability window of 3-4 V. [25][26] Superconcentration concept has also been applied on both Li-metal anode [27] and sulfur-cathode, [28] in the hope that the interphasial chemistries formed by the existing Lithium-sulfur batteries (LSBs) are considered promising candidates for the next-generation energy-storage systems due to their high theoretical capacity and prevalent abundance of sulfur. Their reversible operation, however, encounters challenges from both the anode, where dendritic and dead Li-metal form, and the cathode, where polysulfides dissolve and become parasitic shuttles. Both issues arise from the imperfection of interphases between electrolyte and electrode. Herein, a new lithium salt based on ...

No abstract

We report the first observation of the non-magnetic Barkhausen effect in van der Waals layered crystals, specifically, between the T d and 1T' phases in type-II Weyl semimetal MoTe 2 . Thinning down the MoTe 2 crystal from bulk material to about 25nm results in a drastic strengthening of the hysteresis in the phase transition, with the difference in critical temperature increasing from ~40K to more than 300K. The Barkhausen effect appears for thin samples and the temperature range of the Barkhausen zone grows approximately linearly with reducing sample thickness, pointing to a surface origin of the phase pinning defects. The distribution of the Barkhausen jumps shows a power law behavior, with its critical exponent α = 1.27, in good agreement with existing scaling theory. Temperature-dependent Raman spectroscopy on MoTe 2 crystals of various thicknesses shows results consistent with our transport measurements.zone grows approximately linearly with reducing sample thickness as determined by four-probe resistivity measurement. The distribution of the Barkhausen jumps shows a power law behavior, with its critical exponent = 1.27, consistent with theoretical expectations as explained later in this letter. Temperature-dependent Raman spectroscopy is also performed on MoTe 2 crystals of various thicknesses, showing results consistent with our transport measurements.

The behavior of noise in asynchronous spectrum in generalized two-dimensional (2D) correlation spectroscopy is investigated. Mathematical analysis on the noise of 2D spectra and computer simulation on a model system show that the fluctuation of noise in a 2D asynchronous spectrum can be characterized by the standard deviation of noise in 1D spectra. Furthermore, a new approach to improve a signal-to-noise ratio of 2D asynchronous spectrum by a Butterworth filter is developed. A strategy to determine the optimal conditions is proposed. Computer simulation on a model system indicates that the noise of 2D asynchronous spectrum can be significantly suppressed using the Butterworth filtering. In addition, we have tested the approach to a real chemical system where interaction between berberine and β-cyclodextrin is investigated using 2D UV-vis asynchronous spectra. When artificial noise is added, cross peaks that reflect intermolecular interaction between berberine and β-cyclodextrin are completely masked by noise. After the method described in this article is utilized, noise is effectively suppressed, and cross peaks are faithfully recovered. The above result demonstrates that the approach described in this article is applicable in real chemical systems.

In the quest for solution-processable red electrochromic material with high performance, a series of 3,6-bis­(dodecyloxy)­thieno­[3,2-b]­thiophene (DOTT)-based polymers have been designed by combining DOTT with different aromatic building blocks (bithiophene, benzene, and dimethoxybenzene) and prepared through Pd-catalyzed chemical copolymerization. Among them, the solution-processable polymer poly­(2,5-dimethoxy­phenyl-1,4-diyl-3,6-bis­(dodecyloxy)­thieno­[3,2-b]­thiophene) (P3) showed obvious yellow-green fluorescence in chloroform and demonstrated a rapid reversible switching (1.1 s/0.9 s for doping/dedoping process) between the red and bleached states. This brilliant red polymer exhibited moderate contrast (46% at 510 nm) and excellent cycling stability (in film: 78% for total amount and 63% for reduction after 12000 cycles; in device: 85.6% after 3000 cycles) which qualify it for further device fabrications. This study reveals that this polymer (P3) would be a promising high performance red electrochrome and could be a good candidate for flexible and large-scale organic electrochromic devices as well as for smart indicators or display applications.