Search

In the present work, V2O5 microspheres with the diameters ranging from 1 to 2 μm are prepared by a facile hydrothermal progress, and then V2O5@TiO2 core-shell microspheres are successfully synthesized by a solution method. It is found that the light absorption intensity of V2O5@TiO2 core-shell microspheres is greatly enhanced compared with those of V2O5 microspheres and P25 in UV and visible light ranges. The photodegradation rate towards gaseous benzene of V2O5@TiO2-20% core-shell microspheres is the best one, and it will increase from 27.8% and 10% (pure V2O5 microspheres) to be 100% and 71.8% after 75 min’ irradiation under UV and visible light irradiation, respectively. The reason lies in the fact that the formation of V2O5@TiO2 core-shell microspheres may favor for the light absorption as well as the effective separation of the photoexcited electrons and holes. more...

With the rapid development of perovskite solar cells (PSCs), it is critical to explore efficient and low-cost inorganic hole transport materials (HTMs) to solve the instability issue of the traditional organic HTM spiro-OMeTAD. Herein, Cu12Sb4S13 quantum dots (QDs) are applied as inorganic HTMs in n–i–p planar PSCs, the bandgap aligned the QDs is achieved by the modulation of the QD size to accelerate hole transport from the perovskite layer to QDs, and a power conversion efficiency (PCE) of 14.13% is achieved for 5.7 nm sized QDs. IPCE and UV-vis spectra indicate that the light absorption intensity of Cu12Sb4S13 QD based PSCs is slightly higher than that of the spiro-OMeTAD based one, which enables the enhancement of JSC (21.85 mA cm−2) for PSCs. The excellent hole transport behavior of Cu12Sb4S13 QDs proves that Cu12Sb4S13 QDs may be considered as an efficient and potential candidate of HTMs in PSCs. Moreover, the stability of the Cu12Sb4S13 QD based PSCs is significantly improved compared with that of the spiro-OMeTAD based one due to the high stability of Cu12Sb4S13 QDs and 91% of the initial PCE is retained after 30 days in ambient air. more...

Black phosphorus (BP) has gained great attention as a potential candidate in the photocatalytic field due to its tunable bandgap and high-mobility features, however, poor stability behavior and the high charge recombination of BP limit its practical application. In the present work, a liquid phase exfoliation method is employed to prepare layered BP. The as-prepared layered BP is decorated on TiO2 nanosheets to form a TiO2 nanosheets@BP composite, which stabilizes BP existence under a hydro-oxygen environment. Whereafter, the photocatalytic properties of the TiO2 nanosheets@BP composite towards the degradation of Rhodamine B (RhB) are proven to be greatly enhanced compared to those of pure layered BP and TiO2 nanosheets, and the photodegradation rate reached 98% after 120 minutes irradiation under UV-Vis light. It is worth mentioning that the photocatalytic cycling performance of the TiO2 nanosheets@BP composite remained at 92.5% under the irradiation of UV-Vis light after three cycles. The main reason for this lies in the fact that the formation of the TiO2 nanosheets@BP composite may favor light absorption and effectively reduce the recombination of electron–hole pairs. more...

The growing demands for reproducible and clean sources of power has prompted the exploitation of novel materials for solar-energy conversion; in any case, the improvement of their conversion efficiency remains a big challenge. We report a mixed-dimensional heterostructure to synchronously enhance charge separation and light-absorption of the photoanodes via the introduction of two-dimensional reduced graphene oxide and zero-dimensional CuSbS2 quantum dots on one-dimensional TiO2 arrays. The experimental results show that the graphene sheets with a low Fermi level and a superior electron mobility accept photo-excited electrons from TiO2 and enable fast electron transportation; while the CuSbS2 quantum dots promote the visible light-absorption of the photoanode. The synergistic effects in this mixed-dimensional (1D–2D–0D) heterostructure photoanode induce a markedly raised photoconversion efficiency of 1.2% at 0.3 V and a photocurrent density of 5.5 mA cm−2 at 0.4 V. Furthermore, the photocurrent density of the mixed-dimensional heterostructure exceeds previously reported TiO2-based photoanodes in neutral media. The improved photoelectrochemical properties are attributed to the synergistic-effect-induced highly organized, mixed-dimensional architectures. It is expected that the mixed-dimensional heterostructure photoanode will be a potential candidate for applications in environmental remediation and energy fields. more...

The obscurity in selectivity mechanism has resulted in dilemmas in the research of selectivity properties of metal oxide semiconductor (MOS) gas sensing materials. In this work, selectivity mechanism of ZnO nanorod arrays to CH3OH is revealed by systematically simulating response and recovery reactions of three gas molecules (CH3OH, NH3 and CO) based on density functional theory (DFT). Results suggest that selectivity to CH3OH is due to three factors: i. Response reaction of CH3OH on ZnO (1 0 1 - 0) is most exothermic, which is main reason for the selectivity against NH3. ii. Intermediates as well as products oxidized from CH3OH have strongest absorption ability, which hinders reabsorption of O2 molecule, mainly leading to selectivity against CO. iii. H adatoms dissociated from CH3OH transfer most electrons to ZnO surface layers, which is also responsible for the selectivity. This work provides a new insight into selectivity mechanism and a practicable method to predict selectivity properties of MOSs. more...

B-doped TiO2 microspheres are prepared by the traditional hydrothermal method. The morphologies and microstructures of B-doped TiO2 microspheres are characterized by FESEM, X-ray diffraction (XRD), UV-Vis and BET surface area measurements. The result shows that B doping may inhibit the crystal growth of TiO2 anatase phase and also increase the specific surface area of B-doped TiO2 microspheres, and the specific surface area is of 182.48 m2/g when B/Ti ratio is 0.6. B-doped TiO2 microspheres show an enhanced photo-catalytic activity under the irradiation of visible light, which may totally photo-degrade the gaseous benzene within 70 min. more...

Flexible photovoltaic devices have wide applications in many unique areas. However, the interparticle connection of photo-electrode in flexible photovoltaic devices still needs to be improved. Here, TiO2 slurries have been prepared by a three-step process, which are employed to prepare the photo-anode for flexible CuInS2 quantum dot sensitized solar cells (QDSSCs). 5 nm-sized TiO2 nanoparticles and hydrochloric acid (HCl) have been introduced in 20 nm-sized TiO2 based photo-electrodes under TiO2/HCl mass ratio of 3:1, which exhibits excellent photovoltaic performance and charge transfer property. Due to the interparticle connection enhancement by suitable content of 5 nm-sized TiO2 nanoparticles, photo-anodes with the 20/5-TiO2 nanoparticles mass ratio of 3:1 exhibits the better optical absorption property and photovoltaic performance of flexible QDSSCs. Moreover, there has maintained 98% photovoltaic conversion efficiency of flexible QDSSCs with the seriously curving condition, which can be considered the great foreground in future applications. more...

All-inorganic CsPbI3 quantum dots perovskite solar cells (QDPSCs) have wide potential application due to their excellent photoelectric properties with high environmental stability. However, the poor interface contact between the light absorption layer and hole transport layer (HTL) results in the serious carrier recombination and the large open-circuit voltage (VOC) loss. Herein, we introduce the insulating PMMA (poly(methyl methacrylate)) buffer layer into CsPbI3 quantum dots (QDs)/Cu12Sb4S13 QDs HTL interface in all-inorganic QDPSCs with the structure of FTO/c-TiO2/m-TiO2/CsPbI3 QDs/Cu12Sb4S13 QDs/Au. The interface carrier recombination is obviously suppressed and the significant VOC improvement from 1.04 V to 1.14 V is obtained with the incorporated PMMA buffer layer. The devices with PMMA buffer layer show the enhanced power conversion efficiency (PCE) of 10.99%, and the improvement of 9.71% is achieved compared to that of the control devices (10.02%). The stability is significantly enhanced due to the intrinsic hydrophobic characteristic of PMMA, and the devices retain 62.69% of their initial PCE after stored in air condition for 15 days, which is greatly improved compared with the control device without PMMA. more...

The potential sensor materials of scroll-like dodecylamine-templated vanadium oxide VO x nanotubes doped with Co 2+ or Fe 3+ have been prepared using a sol-gel technique followed by the hydrothermal treatment. The resultant samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning and transmission electron microscopies, thermal and elemental analysis. The gas sensing properties of the metal cations doped VO x nanotubes have been tested in the wide range of working temperatures and targets’ concentrations towards ammonia, ethanol, methanol, toluene and acetone. The highest sensor activity was revealed for ethanol. Stability and electronic properties of pristine and metal doped VO x layers as well as their ad-complexes with O 2 as intermediates during the working process of a sensor were studied by DFT calculations. The study suggests two different mechanisms of cations' action on sensing properties of a VO x compound. In absence of steric obstacles, Co 2+ doing is predicted to be the most efficient dopants for beneficial activation of VO x sensing properties. more...

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. more...

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. more...

The development of novel sensing materials is the key issue for the effective detection of ammonia gas at room temperature. In the present work, the novel 3-D cocoon-like architectures of PbS quantum dots (QDs)/reduced graphene oxide (rGO) composites are self-assembled by using one-step liquid phase method, and the formation process may be vividly depicted by the natural formation process of the ‘silk cocoons’. 3-D PbS QDs/rGO nanococoons show a good detection limit of 750 ppb towards ammonia gas at room temperature, which is significantly enhanced compared with those of pure PbS QDs and rGO. Meanwhile, the gas sensing response will be greatly decreased with the increasing of the working temperature and there is no response at 150 °C, resulting from Schottky barrier modulation. The abnormal dependence of the gas response on the working temperature may be a unique fingerprint calibration for the ammonia detection. In addition, 3-D PbS QDs/rGO nanococoons have a relatively good selectivity towards ammonia gas at room temperature compared with ethanol, acetone and so on, and the long term test proves that they possess an excellent sensing stability. The sensing enhancement at room temperature may be due to the 3-D special architecture and well-combined interfaces of 3-D PbS QDs/rGO nanococoons, which may favor for the absorption of the gas molecules and the fast charge transport from PbS QDs to rGO, respectively. more...

Carbon coated Na5V12O32 ultralong nanowires were synthesized by hydrothermal and solid-state reaction methods As a cathode material for sodium-ion batteries (SIBs), carbon coated Na5V12O32 ultralong nanowires exhibit high electrochemical performance with the redox potential ca. 2.8 V vs. Na+/Na, delivering initial discharge capacity of 105 mAh g−1 at a rate of C/50. Furthermore, Carbon coated Na5V12O32 ultralong nanowires have the tap density of 3.2 g cm−3 and volumetric energy density 940 Wh L−1. Results are confirmed that the carbon coating film with 10 nm thickness could effectively improve the electrochemical performance, and carbon coated Na5V12O32 ultralong may be used as cathode material for SIBs with highly environmental friendship and low cost. more...

Laser soldering has been widely used in the connection of the electronic components and printed circuit boards. Normally, the temperature and thermal stress of solder joints significantly influence the soldering performance and the reliability of solder joints. However, it is difficult to be accurately measured by the experiment during laser soldering process. In order to reveal the effect of laser process parameters on the temperature and thermal stress of SnAgCu solder joints, a novel 3D transient thermo-mechanical coupling numerical model is proposed using finite element method. The numerical simulation results reveal that the temperature and the thermal stress as well as the deformation of the as-soldered samples are proportional to laser output power and output time. These results demonstrate that the fine and uniform microstructure is obtained for SnAgCu solder and the micro Vickers hardness reaches to the maximum value of 38.3 N at the condition of laser output power of 16 W and laser output time of 0.8 s. The good consistency between the experimental and simulation results proves that the finite element model may effectively predict the temperature distribution and stress distribution, which provides a new pathway for the optimization of the laser soldering parameters in the application of electronic components and PCB. more...

TiO 2 nanoparticle and nano-array structures including nanorods, nanowires and nanotubes are prepared for the photo-electrodes of CuInS 2 quantum dot sensitized solar cells, which are investigated the balance on charge generation, separation and transfer performance in solar cells. The optical absorption properties and PL spectra of different photo-electrodes are investigated, which indicates better charge generation property for nanoparticle structure and better charge separation property for nano-arrays structure. With the grain boundary of nanoparticle films and excellent charge transfer performance of nano-arrays films, higher short-circuit current density value has been performed for all the nano-array structure based solar cells. Due to the relative large surface area of three nano-arrays structure for charge generation, excellent charge separation and transfer performance, the TiO 2 nanotube based CuInS 2 quantum dot sensitized solar cells exhibits greater photovoltaic efficiency than other nanostructures, which can support the progress for further photovoltaic performance enhancement on quantum dot sensitized solar cells. more...

Vanadia (V 2 O 5 ) nanorod arrays were grown by oxidizing vanadium foil at five different voltages for 3 h through electrochemical anodic oxidation method. Dense aligned nanorods with L/D ratio 4.75-4.88 (diameter D ≈ 40–45 nm and length ≈ 190–220 nm) were grown at the optimized voltage 55 V. The dominant existence of V 2 O 5 phase and its layered structure were verified by XPS and Raman spectrum analysis respectively. Linear I–V characteristic curve of the sensor based on V 2 O 5 nanorod arrays confirms its Ohmic contact with the electrodes. Gas sensing investigations of the sensor reveals its n-type behavior with the average response magnitude of 6.13 in N 2 atmosphere, which signifies the industrial application of the sensor in a gaseous atmosphere. The sensor shows remarkable static response towards ethanol with lower detection threshold of 800 ppb and a maximum response magnitude of 7.27 at 500 ppm. Based on variable resistance model, a suitable gas sensing mechanism is also established. more...

The phase and chemical compositions of precipitates formed in the system Zn(VO3)2–HCl–VOCl2–H2O at pH 1−3, molar ratio V4+: V5+ = 0.1−9, and 80°C were studied. It was shown that, within the range 0.4 ≤ V4+: V5+ ≤ 9, zinc vanadate with vanadium in a mixed oxidation state forms with the general formula ZnxV4+ yV5+ 2-yO5 ∙ nH2O (0.005 ≤ x ≤ 0.1, 0.05 ≤ y ≤ 0.3, n = 0.5−1.2). Vanadate ZnxV2O5 ∙ nH2O with the maximum tetravalent vanadium content (y = 0.30) was produced within the ratio range V4+: V5+ = 1.5−9.0. Investigation of the kinetics of the formation of ZnxV2O5 ∙ nH2O at pH 3 determined that tetravalent vanadium ions VO2+ activate the formation of zinc vanadate, and its precipitation is described by a second-order reaction. It was demonstrated that, under hydrothermal conditions at pH 3 and 180°C, zinc decavanadate in the presence of VOCl2 can be used as a precursor for producing V3O7 ∙ H2O nanorods 50–100 nm in diameter. more...

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. more...

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. more...

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. more...

CuInS 2 and PbS quantum dots (QDs) are prepared by successive ionic layer adsorption and reaction (SILAR) process for photo-anode of quantum dot sensitized solar cells (QDSSCs). And the optical properties and photovoltaic performance of CuInS 2 and PbS QDSSCs with different structure are investigated. The absorption intensity is obviously enhanced and absorption edge is expanded to the near-infrared region for the TiO 2 /PbS/CuInS 2 QDSSCs. The TiO 2 /3PbS/4CuInS 2 QDSSCs have the great photovoltaic conversion efficiency of 2.93%, which is attributed to the better photocurrent response at long wavelength region and band energy level matching of CuInS 2 and PbS QDs to improve charge generation and transfer performance. more...

Both the canonical Wnt signaling and androgen signaling are important factors regulating prostate organogenesis. How these two pathways crosstalk to regulate prostate stem cell functions remain unclear. Here, we show that while canonical Wnt activity is required for prostate basal stem cell multipotency in vivo, ectopic Wnt activity does not promote basal-to-luminal cell differentiation. We provide evidence that androgen signaling may keep Wnt activity in check. In prostate organoid culture from basal cells, dihydrotestosterone (DHT) antagonizes R-spondin-stimulated organoid growth in a concentration-dependent manner. Molecular analyses of organoids under different treatment conditions showed that androgen signaling down-regulated the expressions of a Wnt reporter as well as many Wnt target genes. Pathway analysis and gene set enrichment analysis of organoid RNA-seq data also revealed the canonical Wnt signaling as a key pathway distinguishing organoids treated with or without DHT. Notably, DHT treatment enhanced AR and β–catenin binding in the nuclei of prostate organoids, providing possible mechanistic clues. Our results reveal a critical role of AR signaling in modulating canonical Wnt activity in prostate basal cells to regulate their multipotency. more...

The growing demands for reproducible and clean sources of power has prompted the exploitation of novel materials for solar-energy conversion; in any case, the improvement of their conversion efficiency remains a big challenge. We report a mixed-dimensional heterostructure to synchronously enhance charge separation and light-absorption of the photoanodes more...

Background As the last link in the chain of cardiovascular events, chronic heart failure (CHF) has high morbidity, high mortality, and poor prognosis. It is one of the main causes of death and disability worldwide. As a new drug for the treatment of chronic cardiovascular disease, dapagliflozin, the efficacy, and safety issues are still the focus of attention. Therefore, we conducted a meta-analysis to evaluate the efficacy and safety of dapagliflozin in the treatment of CHF. Methods According to the search strategy, regardless of publication date or language, randomized controlled trials (RCTs) of dapagliflozin for CHF will be retrieved from 8 databases. First of all, the literature was screened according to the eligibility criteria, and use the Cochrane Collaboration's tool to assess the quality of the included literature. Then, using Rev Man 5.3 and STATA 14.2 software for traditional meta-analysis. Finally, the evaluation of the quality of the evidence and the strength of the recommendations will adopt the Grading of Recommendations, Assessment, Development and Evaluation method. Results This study will evaluate the efficacy and safety of dapagliflozin for CHF, thereby providing more evidence support for clinical decision-making in CHF. Conclusion Our research will provide more references for the clinical medication of patients with CHF. Protocol registration number INPLASY202150046. more...

In order to achieve global energy demand by sustainable energy development and grappling climate change, the ultimate plan is the reduction and conversion of carbon dioxide (CO2). However, in the field of photocatalytic reduction CO2, developing stable, low-cost, and efficient catalyst is still a significant challenge. A series of Cd0.2Zn0.8S@Ti3C2 nanocomposites with different Ti3C2 loading contents are prepared by three-step solvothermal method. Photocatalytic efficiencies of different Cd0.2Zn0.8S@Ti3C2 nanocomposites under visible-light irradiation show that Cd0.2Zn0.8S@Ti3C2 nanocomposite with 5 wt% of Ti3C2 exhibits significant improvement in the photocatalytic performance of CO2 reduction, which shows significant CO (3.31 μmol h−1 g−1) and CH4 (3.51 μmol h−1 g−1) production rates. Such a considerable increase in the photocatalytic efficiency is due to an efficient electron-hole separation and transfer at the interface between Cd0.2Zn0.8S and Ti3C2, which is confirmed by photoluminescence (PL) and electrochemical impedance spectroscopy (EIS). In addition, Cd0.2Zn0.8S@Ti3C2 nanocomposites exhibit high cycling stability during the CO2 photocatalytic reduction, and the photocatalytic mechanism is also discussed. more...

A new method has been developed for the synthesis of diammonium trivanadate (NH 4 ) 2 V 3 O 8 . Single crystals of (NH 4 ) 2 V 3 O 8 were synthesized on a large scale by a soft base hydrolysis of NH 4 VO 3 in NH 4 OH solution in the presence of VOSO 4 ·3H 2 O. The effects of vanadium(V) concentration, pH value on the product morphology and phase composition were investigated. The formation mechanism of (NH 4 ) 2 V 3 O 8 was suggested. The samples were characterized using combination of techniques including X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, nuclear magnetic spectroscopy, nitrogen adsorption/desorption isotherms, and thermal analysis. Electronic structure, chemical bonding and adsorption properties of the bulk compound and (001) surface were analyzed by means of DFT calculations. more...

Here we address the optoelectronics properties of CuInSe2 and Mn doped CdS quantum dot (CISe/Mn-CdS QD) passivated layer solar cells. CISe/Mn-CdS QD solar cells exhibit a remarkably enhanced optical absorption in the visible region as well as monochromatic incident photon-to-electron conversion efficiency (IPCE) (up to 40–90%), which present the interesting photovoltaic efficiency of 3.96% under one sun illumination. Such remarkable optical behavior of the CISe/Mn-CdS QD passivated solar cells is explained by an optical mechanism based on an energy band model and valid physical laws. more...

Zn doped MoO 3 nanobelts with the thickness of 120–275 nm, width of 0.3–1.4 μm and length of more than 100 μm are prepared by hydrothermal reaction. The operating temperature of sensors based on Zn doped MoO 3 nanobelts is 100–380 °C with a better response to low concentration of ethanol. The highest response value of sensors based on Zn doped MoO 3 to 1000 ppm ethanol at 240 °C is 321, which is about 15 times higher than that of pure MoO 3 nanobelts. The gas sensors based on Zn doped MoO 3 nanobelts possess good selectivity to ethanol compared with methanol, ammonia, acetone and toluene, which implies that it would be a good candidate in the potential application. The improvement of gas sensing properties may be attributed to the increasing absorbed ethanol, the decreasing probability of ethoxy recombination, the promoted dehydrogenation progress at lower temperature, and the narrowed band gap by Zn doping. more...

TiO2 hollow spheres are prepared by a template method, and TiO2@V2O5 core-shell hollow porous microspheres are successfully synthesized through a facile hydrothermal progress followed by sol-gel technique. The diameters of TiO2@V2O5 core-shell hollow porous microspheres are quite uniform ranging from 700 nm to 900 nm. It is found that the photodegradation rate of TiO2@V2O5 core-shell hollow porous microspheres towards benzene is greatly enhanced compared with that of TiO2 hollow porous microspheres and P25, and TiO2@V2O5-10% core-shell hollow porous microspheres possess the best photocatalytic activity of 100% in 55 min and 68.9% in 75 min under UV-visible and visible light irradiation, respectively. The reason lies in the fact that the light absorption range is extended due to the narrowed band gap of TiO2@V2O5 core-shell hollow porous microspheres, and the photogenerated electrons and holes are effectively separated as well as the surface charge carrier transfer rate is promoted. more...

In this paper, Pb(Zr0.52Ti0.48)O3 (PZT) thin films were prepared via sol-gel method. The effects of Ba(Mg1/3Ta2/3)O3 (BMT) buffer layer on the temperature dependence and dielectric tunability properties of PZT thin films were studied. As the thickness of BMT buffer layer increases, the tan δ and tunability of PZT thin films decrease while tunability still maintains above 10%. This result shows that BMT buffer layer can improve the dielectric tunability properties of PZT thin films. Furthermore, the temperature coefficient of the dielectric constant decreases from 2333.4 to 906.9 ppm/°C with the thickness of BMT buffer layer increasing in the range from 25 to 205 °C, indicating that BMT buffer layer can improve the temperature stability of PZT thin films. Therefore, BMT buffer layer plays a critical role in improving temperature dependence and dielectric tunability properties of PbZr0.52Ti0.48O3 thin films. more...

Surface states are significant factor for the enhancement of electrochemical performance in CuInS 2 quantum dot sensitized photo-electrodes. DDT, OLA, MPA, and S 2− ligand capped CuInS 2 quantum dot sensitized photo-electrodes are prepared by thermolysis, solvethermal and ligand-exchange processes, respectively, and their optical properties and photoelectrochemical properties are investigated. The S 2− ligand enhances the UV–vis absorption and electron–hole separation property as well as the excellent charge transfer performance of the photo-electrodes, which is attributed to the fact that the atomic S 2− ligand for the interfacial region of quantum dots may improve the electron transfer rate. These S 2− -capped CuInS 2 quantum dot sensitized photo-electrodes exhibit the excellent photoelectrochemical efficiency and IPCE peak value, which is higher than that of the samples with DDT, OLA and MPA ligands. more...

In the present work, PbS quantum dots/TiO 2 nanotubes arrays (PbS QDs/TiO 2 NTARs) are prepared by successive ionic-layer adsorption and reaction, which are used to fabricate the gas sensor. The gas sensing performance shows that PbS QDs/TiO 2 NTARs possess a good response towards ammonia gas at room temperature. PbS QDs/TiO 2 NTARs sensitized with 0.1 M concentration and 6 cycles possess the best gas response, and the gas response could reach 17.49 for 100 ppm ammonia with a detection limit of 2 ppm at room temperature. It also proves that PbS QDs/TiO 2 NTARs have a quite good selectivity towards ammonia compared with ethanol, methanol, acetone and toluene at room temperature. The enhanced sensing mechanism is also discussed. more...

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. more...

In the present work, ultralong MoO3 nanobelts are prepared by a facile hydrothermal method, which are flexible with an average length of 200 μm and width of 200–400 nm. Gas sensor based on ultralong MoO3 nanobelts shows a remarkable gas sensing properties towards trimethylamine (TMA) from 100 °C to 380 °C with a humidity level of about 55%. The optimum operating temperature is 240 °C with a response of 582 to 50 ppm TMA in static mode. The selectivity test among various reducing gases shows that the sensor has a quite good response towards TMA if compared with others gases, such as ethanol, ammonia, toluene, methanol and acetone. The probable gas sensing mechanism of the prepared MoO3 nanobelts is discussed as well. The results indicate that this kind of sensor has a promising application in TMA detection. more...

Flexible perovskite solar cells (PSCs) have attracted much attention of the researchers due to their wide application. However, the great challenge in developing flexible PSCs is preparing the electron transport layer (ETL) at lower temperatures to meet with the processing requirements of plastic substrates. Herein, we introduce a facile sol-gel method for the preparation of the compact TiO2 (c-TiO2) ETL below 150 °C. By regulating the precursor solution concentration, annealing temperature and time of TiO2 ETL, we find that the c-TiO2 ETL exhibits the best photoelectric performance with the concentration of TiO2 precursor solution of 2 M, the annealing temperature of 150 °C and annealing time of 30 min, which exhibits the fastest electron extraction and lowest possibility of the charge carrier recombination. In final, a high power conversion efficiency of 16.11% is obtained with the planner structure of PEN/ITO/c-TiO2/MAPbI3/Spiro-OMeTAD/Au, which is the excellent one compared with the similar works, and the flexible PSCs also possess the good bending stability after 500 bending cycles. more...

Air infiltration of the building is closely related to its indoor thermal environment, indoor air quality and energy consumption. It is known that, there have been only a few studies focusing on the prediction of air infiltration rate in public buildings in the cold area of China. In this paper, the airtightness of three typical zones of public buildings was tested and their air infiltration rates for 1800 cases were simulated based on the test results. Field tests show that the air change rates under the pressure difference of 50 Pa of the three zones are 3.8 h−1, 4.4 h-1, and 5.2 h−1, respectively. The airtightness of the zones built later (2007) is even worse than that built much earlier (1990). Simulations show that the air infiltration rate ranges from 0.01 h−1 to 0.23 h−1 with an average of 0.09 h−1 for zone 1, from 0.03 h−1 to 0.87 h−1 with an average of 0.37 h−1 for zone 2, and from 0.05 h−1 to 1.05 h−1 with an average of 0.50 h−1 for zone 3, respectively. The frequency of the AIR of all the three zones presents a logarithmic normal distribution. Discussion shows that the impact of air infiltration on public buildings should be fully considered when designing the HVAC system. more...

The layered oxide cathodes with low and moderate nickel contents used in Li-ion batteries with high-voltage and energy density are receiving considerable attention, as they possess better cycle performance and higher safety compared with high-nickel cathode. In the work, the crystal structure and electrochemical performance at 4.6 V high voltage vs Li+/Li are studied by controlling the lithium content in Li1+xNi0.45Co0.1Mn0.45O2 (0.05 ≤ x ≤ 0.4). As the lithium content in Li1+xNi0.45Co0.1Mn0.45O2 increases, the as-synthesized sample is mixed with hexagonal R-3m and monoclinic C/2 m crystals, accompanied with the decreasing of a/c axis ratio and cation mixing. Consequently, the reversible capacities of Li1.3Ni0.45Co0.1Mn0.45O2 reach 208 mAh/g at C/10 and 115 mAh/g at a high rate of 10C, respectively. The suitable Li content can lead to the low anion mixing crystal structure and best electrochemistrical performance. more...

Black phosphorus (BP) has gained great attention as a potential candidate in the photocatalytic field due to its tunable bandgap and high-mobility features, however, poor stability behavior and the high charge recombination of BP limit its practical application. In the present work, a liquid phase exfoliation method is employed to prepare layered BP. The as-prepared layered BP is decorated on TiO2 nanosheets to form a TiO2 nanosheets@BP composite, which stabilizes BP existence under a hydro-oxygen environment. Whereafter, the photocatalytic properties of the TiO2 nanosheets@BP composite towards the degradation of Rhodamine B (RhB) are proven to be greatly enhanced compared to those of pure layered BP and TiO2 nanosheets, and the photodegradation rate reached 98% after 120 minutes irradiation under UV-Vis light. It is worth mentioning that the photocatalytic cycling performance of the TiO2 nanosheets@BP composite remained at 92.5% under the irradiation of UV-Vis light after three cycles. The main reason for this lies in the fact that the formation of the TiO2 nanosheets@BP composite may favor light absorption and effectively reduce the recombination of electron-hole pairs. more...

The stability and photovoltaic conversion efficiency are very important issues for the industry application of flexible solar cells, which have been seriously limited by the interface connection of basic photo-electrodes in solar cells. Here, one-dimensional TiO2 nanowire arrays films were employed as photo-electrodes of flexible solar cells, which have modulated interface connection of the photo-electrodes by introducing small size of nanoparticles and heating pressure process. The charge generation and separation properties of photo-electrodes have been influenced, which may be attributed by the changes on band energy of small size of nanoparticles in photo-electrodes. With the improvement on the interface connection in the photo-electrodes, the charge transfer property has been effectively improved, which have exhibited a higher current density value of the solar cells, achieving photovoltaic conversion efficiency enhancement from 2.55% to 3.90%. Moreover, there have no obvious changes on the photovoltaic conversion efficiency of these flexible QDSSCs solar cells under the curling condition. more...

Novel CuSbS

To investigate the therapeutic effect of Check ligament suspension for congenital severe blepharoptosis.From Jan.2015 to Jan.2016,28 cases with severe congenital ptosis were treated by suspension of Check ligament to tarsus. The postoperative effect, curve of upper eyelid and complication were recorded.All the patients were followed up for 3-12 months. Complete correction was achieved in 24 cases, while undercorrection in 4 cases. Among the 24 cases with good results, they had symmetric palpebral fissure and natural curve of upper eyelid. Eye closure function recovered within 6 months in 19 cases. No complication, like corneal exposure, happened. Among the 4 cases with undercorrection result,2 underwent no further treatment due to marked improvement,2 underwent re-operation 6 months after the first operation with good result.Suspension can successfully correct severe congenital blepharoptosis with natural recovery of eyelid structure. more...

Genetically engineered mouse models (GEMMs) are extremely valuable in revealing novel biological insights into the initiation and progression mechanisms of human diseases such as cancer. Transgenic and conditional knockout mice have been frequently used for gene overexpression or ablation in specific tissues or cell types in vivo. However, generating germline mouse models can be time-consuming and costly. Recent advancements in gene editing technologies and the feasibility of delivering DNA plasmids by viral infection have enabled rapid generation of non-germline autochthonous mouse cancer models for several organs. The bladder is an organ that has been difficult for viral vectors to access, due to the presence of a glycosaminoglycan layer covering the urothelium. Here, we describe a novel method developed in lab for efficient delivery of DNA plasmids into the mouse bladder urothelium in vivo. Through intravesical instillation of pCAG-GFP DNA plasmid and electroporation of surgically exposed bladder, we show that the DNA plasmid can be delivered specifically into the bladder urothelial cells for transient expression. Our method provides a fast and convenient way for overexpression and knockdown of genes in the mouse bladder, and can be applied to building GEMMs of bladder cancer and other urological diseases. more...

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. more...

CuInS2 quantum dots (QDs) with different sizes are synthesized by a solvothermal process, and then linked on the FTO conducting glass and TiO2 nanoparticle films. Photoluminescence (PL) lifetimes measured by time-resolved PL decay indicate that PL lifetimes firstly increase then decrease with the size increasing of CuInS2 quantum dots, which is due to the ratio between the radiative excitons traps and nonradiative excitons traps. Temperature-independent PL spectra of the 4.9 nm CuInS2 QDs prove that there is no emission peak shift from 5 K to 200 K, which is related with the emission from the trapped states, and the linear fitting character of the temperature dependence of the full width at half maximum comes from the coupling of the carriers to the acoustic phonons modes. With the CuInS2 quantum dots linking on TiO2 nanoparticle films, the PL lifetime is obviously reduced. The gradually larger conduction band energy offset between CuInS2 quantum dots and TiO2 induces the PL lifetime reducing with the size decreasing of the CuInS2 QDs, which can induce the faster electron injection rate constant for the CuInS2 quantum dots with small size. more...

Hexagonal molybdenum trioxide (h-MoO3) microrods were successfully synthesized via a novel and facile hydrothermal route from peroxomolybdate solution with the presence of NH4Cl as the mineralizer. A variety of the techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry combined with the thermal gravimetric analysis (DSC–TG) were used to characterize the product. The gas sensing test indicates that h-MoO3 microrods have a good response to 5–500 ppm ethanol in the range of 273–380 °C, and the optimum operating temperature is 332 °C with a high sensitivity of 8.24 to 500 ppm ethanol. Moreover, it also has a good selectivity toward ethanol gas if compared with other gases, such as ammonia, methanol and toluene. The sensing mechanism of h-MoO3 microrods to ethanol was also discussed. more...