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The precise construction of photocatalysts with diatomic sites that simultaneously foster light absorption and catalytic activity is a formidable challenge, as both processes follow distinct pathways. Herein, an electrostatically driven self-assembly approach is used, where phenanthroline is used to synthesize bifunctional LaNi sites within covalent organic framework. The La and Ni site acts as optically and catalytically active center for photocarriers generation and highly selective CO2-to-CO reduction, respectively. Theory calculations and in-situ characterization reveal the directional charge transfer between La-Ni double-atomic sites, leading to decreased reaction energy barriers of *COOH intermediate and enhanced CO2-to-CO conversion. As a result, without any additional photosensitizers, a 15.2 times enhancement of the CO2 reduction rate (605.8 μmol·g−1·h−1) over that of a benchmark covalent organic framework colloid (39.9 μmol·g−1·h−1) and improved CO selectivity (98.2%) are achieved. This work presents a potential strategy for integrating optically and catalytically active centers to enhance photocatalytic CO2 reduction.

The regularity for the 3-D nematic liquid crystal equations is considered in this paper, it is proved that the Leray–Hopf weak solutions (u, d) is in fact smooth, if the velocity field $$u\in L^\infty (0,T;L^{3,\infty }_x(\mathbb {R}^3))$$ satisfies some addition local small condition $$\begin{aligned} r^{-3}\left| \left\{ x\in B_r(x_0): |u(x,t_0)|>\varepsilon r^{-1}\right\} \right| \le \varepsilon , \end{aligned}$$ which is inspired by the papers [2, 35].

All-inorganic zero-dimensional (0D) tetrahedrite (Cu12Sb4S13, CAS) quantum dots (QDs) have attracted extensive attention due to their excellent optical properties, bandgap tunability, and carrier mobility. In this paper, various sized CAS QDs (5.1, 6.7, and 7.9 nm) are applied as a switching layer with the structure F:SnO2 (FTO)/CAS QDs/Au, and in doing so, the nonvolatile resistive-switching behavior of electronics based on CAS QDs is reported. The SET/RESET voltage tunability with size dependency is observed for memory devices based on CAS QDs for the first time. Results suggest that differently sized CAS QDs result in different band structures and the regulation of the SET/RESET voltage occurs simply and effectively due to the uniform size of the CAS QDs. Moreover, the presented memory devices have reliable bipolar resistive-switching properties, a resistance (ON/OFF) ratio larger than 104, high reproducibility, and good data retention ability. After 1.4 ×106 s of stability testing and 104 cycles of quick read tests, the change rate of the ON/OFF ratio is smaller than 0.1%. Furthermore, resistive-witching stability can be improved by ensuring a uniform particle size for the CAS QDs. The theoretical calculations suggest that the space-charge-limited currents (SCLCs), which are functioned by Cu 3d, Cu 3p and S 3p to act as electron self-trapping centers due to their quantum confinement and form conduction pathways under an electric field, are responsible for the resistive-switching effect. This paper demonstrates that CAS QDs are promising as a novel resistive-switching material in memory devices and can be used to facilitate the application of next-generation nonvolatile memory.

This work reports the hydrothermal synthesis of silver decorated sandwiched-like vanadium pentoxide (Ag–V2O5) nanosheets and their investigation for sensing of ethanol, acetone, n-propylamine and ammonia vapors at room temperature. Sandwich-type architectured (MI–MIO–MIIO) Ag–Ag2O–V2O5 nanosheets have been synthesized here. Structure, morphology and oxidation states of the material were analyzed using X-rays diffraction, FESEM and XPS studies, respectively. Gas sensing characteristics of the sensors based on Ag–V2O5 nanosheets were evaluated both in static and dynamic modes. It was figured out that the behavior of the sensing material is of p-type semiconducting nature with a high sensitivity value (≈22), fast response speed (in seconds) and high selectivity toward ethanol at room temperature which has been explained on the basis of semiconductors models. High sensitivity, quick response and significant selectivity of the sensors confirm their potential applications for environmental, security, food preservation and other industrial purposes.

In the past few years, our group worked on the area of transformation from the two-dimensional (2-D) nanocrystalline films to one-dimensional (1-D) nanomaterials by using thermal oxidation. In this paper, we overview the research work on the controllable growth processes, transformation phenomena, growth mechanisms and applications. In general, the preparation process includes the following steps: 1) prepare a pure metal nanocrystalline film via a pulse electro – deposition; 2) grow variant 1-D nanomaterials, such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), and 1-D metal oxide nanoneedles involving ZnO, CuO and Fe3O4, etc. by using this film as catalyst. This process exhibits the following features: 1) the 1-D nanomaterials grow according to “base growth” model and no residual catalyst exists at the tip of the products; 2) the diameter of the 1-D nanomaterials can be controlled by controlling grain sizes of the 2-D films through adjusting pulse electro-deposition parameters; 3) it is more easily to get the 1-D nanomaterials with large area, uniform, vertical alignment and good shape on the substrates. We propose a “solid state based-up diffusion growth mechanism” for growth of the 1-D metal oxide nanoneedles, and “base growth model” for the 1-D carbon nanomaterials. The physical properties, such as Field emission and magnetics, of the 1-D metal oxide nanoneedles were studied, which showed desired values. In addition, we couple the ZnO nanoneedles with NiO, TiO2, graphene, Au nanoparticles, etc. for enhancing photocatalytic properties in the areas of environmental purification.

Herein, Na5V12O32 has a low conductivity, which restricts its electrochemical performance. In order to use Na5V12O32 in practical sodium-ion batteries (SIBs), nanoflowers were prepared hydrothermally to enhance the electronic conductivity with the increasing of the effective surface area. Each nanoflower has 2D nanosheets with the thickness of ca. 10 nm and length up to 150 nm. Na5V12O32 nanoflowers were then embedded with reduced graphene oxide (rGO) by solid-state reaction process, which gives rise to fast electron transfer. The cathodic behaviour of 5–15 wt% rGO composites with Na5V12O32 nanoflowers is investigated. As a cathode material for SIBs, Na5V12O32 nanoflowers/rGO–10 wt% composite has a redox potential ca. 2.9 V versus Na+/Na and exhibits an excellent reversible cycling with initial discharge capacity of 142 mAh g−1 at a rate of 5C. In addition, Na5V12O32 nanoflowers/rGO–10 wt% composite has a tap density of 3 g cm−3 and volumetric energy density 1242 Wh L−1. These preliminary results indicate that the Na5V12O32 nanoflowers/rGO–10 wt% composite is a promising cathode candidate for SIBs.

One-dimensional single crystalline TiO2 nanotube arrays with different length are prepared, and transferred onto the FTO glass substrate with different concentration of Ti-precursor. The relationships between the concentration of Ti-precursor and the optical properties, as well as the photovoltaic performance of the as-prepared solar cells have been investigated. The optical absorption intensity is obviously enhanced and optical absorption edge is expanded to 800 nm for the CdSe/CdS/TiO2 NTs solar cells. In addition, 20 μm - CdSe/CdS/TiO2 NTs solar cells with 0.1 M Ti-precursor have the great photovoltaic conversion efficiency of 4.18%. The excellent photovoltaic performance is attributed to the suitable TiO2 connection layer from 0.1 M Ti-precursor and length of TiO2 NTs, which greatly enhances the electron-hole generation and charge transfer performance in the solar cells. Finally, the photovoltaic efficiency of the as-fabricated solar cells can be further enhanced to 4.51% through the ZnS passivation layer deposition.

Layered MoS2, which is treated as an alternative candidate of graphene, has attracted great attention due to its large intrinsic band gap and relatively high carrier mobility. It is relatively convenient and inexpensive to prepare MoS2 through chemical synthesis route. Herein, a novel solution-based hot-injection method is used to prepare MoS2. Controlling the reaction time leads to the variation of MoS2 morphologies, which present as quantum dots and nanosheets. Detail studies are carried out to investigate the formation mechanism of MoS2. The results indicate that the formation of layered MoS2 nanosheets follows a bottom-up process, which includes three steps in the order of quantum dots, small pieces and large area nanosheets.

The optical absorption and charge dynamics of different sized CuInS2 quantum dots have been investigated. Exact sizes from 2.5 to 4.1 nm of CuInS2 quantum dots are prepared and further deposited on the TiO2 films. The optical absorption property of CuInS2 quantum dots sensitized photo-electrodes are analyzed by UV–Vis spectra, which provides electron generation property of the photo-electrodes. And the electron–hole separation property of the photo-electrodes is characterized by photoluminescence spectra with different size of quantum dots. The electrochemical impedance spectra and time-resolved photoluminescence decay are employed to measure the charge dynamics, which indicates that better electron transfer property can be obtained by the small size of quantum dots. With the balance of charge generation and charge transfer performance, 3.6 nm sized CuInS2 QDs sensitized photo-electrodes achieves excellent photovoltaic performance.

MoO2 nanoparticles (NPs) and reduced graphene oxide (rGO) nanocomposites (MoO2 NPs/rGO) with different rGO contents were prepared by a two-step hydrothermal process. When the content of rGO was 10 wt%, the MoO2 nanoparticles were uniformly deposited on the rGO nanosheets, and the corresponding MoO2 NPs/rGO nanocomposites also exhibited the highest reversible capacities of 1647 mAh g−1 at the first cycle and 1269 mAh g−1 after 100 cycles. This material also had stable rate capacity for 991 mAh g−1 at 1 mA cm−2. The outstanding electrochemical performance of the nanocomposite may be attributed to the synergistic interaction between MoO2 NPs and rGO, as there were enough void spaces to buffer volume change in the microstructures of the MoO2 NPs/rGO nanocomposites. Furthermore, rGO nanosheets in the MoO2 NPs/rGO nanocomposites could act as not only active materials but also electronic conductive channels to improve the electrochemical performance.

Carbon nanomaterials are viewed as promising building blocks of future nanotechnology because of their superior electrical, thermal, and mechanical properties. Carbon nanomaterials can be synthesized by a variety of methods, in which flames offer a potential route in large quantities at a significantly lower cost. Our group has worked on growth of carbon nanomaterials involving carbon nanotubes (CNTs), carbon nanofibers (CNFs) and graphenes in flames for more than 15 years, and almost 100 journal papers have been published. In this paper, we review the advances in synthesis of carbon nanomaterials from flames in detail together with discussion on the major challenges and opportunities for practical applications.

Background The SstI polymorphism in the apolipoprotein 3 gene (apoC3) has been identified in many ethnic groups. In addition, the S2 allele of the SstI polymorphism is shown to be associated with increased plasma triglyceride (TG) levels. Plasma apoCIII is an important atherogenic factor, which interrupts lipid metabolism and is positively associated with plasma TG levels. However, the existence of the SstI polymorphism in the Li ethnic group in China remains to be confirmed. The relationship between the S2 allele of the SstI polymorphism and plasma apoCIII or TG and their roles in atherosclerosis are also unknown. Methods A cohort of 628 participants was recruited (316 atherosclerotic patients and 312 healthy controls) from both the Li and Han ethnic groups. Blood samples were obtained to evaluate the SstI polymorphism in the apoC3 and lipid profiles. Chi-squared and t-tests and multiple unconditional logistic regression were employed to analyze the genotypic and allelic frequencies and lipid profiles using SPSS version 20.0 software. Results The SstI polymorphism in the apoC3 was identified in the Li ethnic group. The S2 allele and plasma apoCIII and TG levels were associated with the development of atherosclerosis (P

TiO2 nanowire arrays are prepared on Ti wire by a hydrothermal process, which are co-sensitized with CuInS2/Mn-CdS quantum dots to fabricate the solar cells with Cu2S/brass as the counter electrode. The UV–Vis absorption spectra observe that the deposition of CuInS2/Mn-CdS quantum dots on the TiO2 photoanodes obviously improves its optical absorption properties. The influence of the length of TiO2 nanowire arrays is also investigated, which indicates that the solar cells with 20 μm TiO2 nanowire arrays in length have the best photovoltaic performance. The diameter of Cu2S/brass counter electrode has a significant influence on the illuminated area and electrocatalytic ability of the solar cells. For comparison, the fibrous CuInS2/Mn-CdS quantum dot co-sensitized solar cells using the Cu2S counter electrode of 100 μm in diameter exhibits a photovoltaic power conversion efficiency of 3.51 %.

Androgen signals through androgen receptor (AR) to influence prostate development and cancer. How stromal and epithelial AR regulate prostate homeostasis remains unclear. Using genetic lineage tracing, we systematically investigated the role of cell-autonomous AR in different prostate epithelial cell types. Here we show that AR is dispensable for basal cell maintenance, but is cell-autonomously required for the luminal differentiation of rare basal stem cells. In contrast, AR deletion in luminal cells alters cell morphology and induces transient over-proliferation, without affecting androgen-mediated luminal cell survival or regeneration. However, AR is selectively required for the maintenance of daughter cells produced by castration-resistant Nkx3.1-expressing luminal stem cells (CARNs). Notably, Pten loss can override AR-loss effects in both basal and luminal compartments to initiate tumours. Our data reveal distinct cell-type-specific roles of epithelial AR in orchestrating prostate homeostasis, and question the notion that epithelial AR serves as a tumour suppressor in early cancer initiation., Androgen receptor is an important regulator of prostate development and cancer. In this study, the authors use genetic lineage tracing in mice to clarify the role of AR in different prostate epithelial cells.

In this article, the field-emission property of individual CuO nanoneedle was investigated to explore its tip image and real work function using in situ transmission electron microscopy. The maximum emission current of nanoneedle used in this study was 1.08 μA, and two different slopes in the corresponding F–N graph existed with work functions of the CuO nanoneedle being 1.12 and 0.58 eV. In comparison with the single CuO nanoneedle, the field enhancement β and parameter s of the CuO nanoneedle’s film arrays were also studied, which showed that the screening effect played a key role in the field-emission process.

This is a continuation of our previous research on synthesis of carbon nanotubes (CNTs) by using an ethanol flame [1,2]. Previously, we reported that carbon nanotubes (CNTs), including well-aligned CNTs, have been successfully produced on austenitic stainless steels within ethanol flame environment. Recently, a novel solid-cored carbon nanofiber (CNF) was found when using carbon steel or low alloy steel as the substrate. In the present paper, the character of the CNFs and the growth mechanism are discussed.

In the past decades, ferroelectric materials have attracted wide attention due to their applications in nonvolatile memory devices (NVMDs) rendered by the electrically switchable spontaneous polarizations. Furthermore, the combination of ferroelectric and nanomaterials opens a new route to fabricating a nanoscale memory device with ultrahigh memory integration, which greatly eases the ever increasing scaling and economic challenges encountered in the traditional semiconductor industry. In this review, we summarize the recent development of the nonvolatile ferroelectric field effect transistor (FeFET) memory devices based on nanostructures. The operating principles of FeFET are introduced first, followed by the discussion of the real FeFET memory nanodevices based on oxide nanowires, nanoparticles, semiconductor nanotetrapods, carbon nanotubes, and graphene. Finally, we present the opportunities and challenges in nanomemory devices and our views on the future prospects of NVMDs.