查看更多>>摘要：? 2022 Elsevier B.V.LaVO3 is well known as a promising material for use in photovoltaic devices because of its high absorption of visible light. Here, we report on the photovoltaic parameters and photostability of LaVO3/Si/TiOx solar cell devices. In this work, the photovoltaic parameters of the device are controlled via the thickness (t) of the LaVO3 layer; such control is possible because the transmittance, absorbance, and reflectance of this layer are dependent on its thickness. TiOx passivation is also used to reduce the recombination loss at the back surface. Furthermore, TiOx passivation improves the power conversion efficiency (PCE) by blocking recombination at the Si/metal interface. The LaVO3/Si/TiOx cells exhibit a maximum PCE of 6.78% at t = 70 nm. The PCE of the device shows only a 9% decrease after continuous 500 h irradiation at an intensity of 100 mW cm?2 at a temperature of 60 °C and 30–35% relative humidity, suggesting excellent long-term stability.
查看更多>>摘要：? 2022 Elsevier B.V.The electrolysis voltage strongly influences the morphology and thermoelectric performance of materials prepared by electrochemical synthesis. However, the nature of the reaction is not clear up to now. In this paper, skutterudite CoSb3 with different morphologies are synthesized by molten salt electrolysis at various electrolysis voltages, and the effect of electrolysis voltage on the morphology and thermoelectric performance of skutterudite CoSb3 are studied by comparing their SEM patterns as well as electrical conductivity, Seebeck coefficients and thermal conductivity. The electrical conductivities and Seebeck coefficients of the obtained CoSb3 were tested by a four-probe technique. The thermal conductivities were measured by a thermal diffusivity system using Pyroceram as a reference sample. It is found that the electrolysis voltage affects the morphology of the CoSb3 via influencing the relationship between the reaction and diffusion rates. The ZT values of the materials are dependent on their morphologies, grain size and the highest ZT value is 0.028 for petal-like aggregates.
查看更多>>摘要：? 2022 Elsevier B.V.Developing an efficient, robust and low-budget bifunctional material for hydrogen evolution is a daunting challenge, which has attracted plenty of researchers’ interest. Herein, we report the non-noble metal bifunctional g-C3N4/CN/CoP catalysts in situ formed for both photocatalytic and electrocatalytic hydrogen production through a convenient phosphorization process. It was found that the optimal g-C3N4(90)/CN300/CoP3 composite not only had the best photocatalytic hydrogen production rate (29.78 mmol·g?1·h?1) in the dye sensitization system, but also had an excellent electrocatalytic hydrogen evolution activity, with an overpotential of 221 mV at 10 mA·cm?2. The XRD, FT-IR, TG, et al. confirm the close contact between ZIF-Co and g-C3N4 in the ideal g-C3N4/ZIF-Co precursor could expediently achieve the uniformly distributed CoP to accelerate electron transfer and reduce the recombination rate of charge. This work can provide a novel strategy to fabricate non-noble metal dual-functional materials for photocatalytic and electrocatalytic hydrogen production to solve energy crises and environmental further.
查看更多>>摘要：? 2022 Elsevier B.V.Thin nanocrystalline films of gadolinium oxide (undoped and doped with copper ions) were synthesized by means of reactive anodic evaporation technique. Chemical composition inspection and structural-phase analysis of the samples obtained were performed by XPS and XRD methods. Optical characteristics (energy gaps, refractive index, emission parameters) of thin films were determined by means of absorption, transmission and photoluminescence spectroscopies. It was found that injection of copper leads to an insignificant decrease in the transparency gaps for direct and indirect transitions of Gd2O3 film. On the basis of interference effects, a decrease in refractive index and an increase in its dispersion in Gd2O3:Cu film were established. The excited by energy transfer from “defective” Gd3+ ions emission bands at 2.9 eV and 3.2 eV were associated with oxygen vacancies (F+- centers) localized near C2 and S6 cationic positions in Gd2O3 host. The injection of copper ions into Gd2O3 host stimulates the formation of lattice defects and leads to an increase in the luminescence yield. An analytical expression was obtained for describing luminescence flare-up and quenching. The corresponding thermal activation barriers were determined. The transfer of excitation energy between intrinsic defects of Gd2O3 film provides the conversion of hard UV radiation into soft UV and visible radiation.
查看更多>>摘要：? 2022 Elsevier B.V.In Fenton-like reaction, adsorption and degradation are inseparable processes. The pollutants were enriched on the surface of catalyst by adsorption leading to the increase of the local concentration, and this was beneficial for acceleration of the degradation rate. Therefore, a catalyst with high adsorption capacity, low metal leaching and rapid activation rate toward peroxymonosulfate (PMS) was highly desirable. In this paper, Co-doped CeO2 (Co-CeO2) nanoflower was prepared via a solvothermal-calcination process. The nanoflower with a hierarchical porous structure was made up of dozens of nanosheets. Compared to CeO2, more Ce(Ⅲ) sites and defects were generated on Co-CeO2 surface, and the maximum adsorption capacity was increased by 1.92 times. Benefiting from the high activity of Co toward the activation of PMS, the degradation rate was enhanced 6.7 times. The major radicals were determined and the corresponding degradation mechanism was revealed. Additionally, Co-CeO2 nanoflower was demonstrated to be high efficient in many persistent organic pollutant degradation and also exhibited outstanding reusability after several cycles. Moreover, the leaching of toxic Co ions was 12 times lower than the referenced Co3O4. This work provides a promising approach on rational design a catalyst with high adsorption property and degradation efficiency in Fenton-like reaction for environmental remediation.
Pataky G.J.Wang Z.Rodriguez De Vecchis R.Wang X....
14页
查看更多>>摘要：? 2022 Elsevier B.V.The remarkable combination of strength, toughness, and weldability that characterizes high-strength low-alloy (HSLA) steels make them suitable structural materials for naval and automobile applications. The well-studied effect of a microstructure, comprised of co-precipitated Cu and M2C carbides combined with a low carbon content, stands at the root of this superior synergy of properties. However, to advance in the innovation of stronger, lighter, and compositionally lean steels, new precipitation strengthening routes need to be explored. In this regard, Heusler compounds have proven promising for a selected group of structural alloys but have so far been untested in HSLA steels. Hence, in this work, two compositions close to HSLA-115 steel had been designed with the Fe2SiTi Heusler phase as its major strengthening phase. Modeling and experiments were carried out to describe the evolution of phase transformation and precipitation behavior. Results indicate a record high peak aged hardness of 717 HV arising from the contribution of the Fe2SiTi phase acting as a grain refiner as well as by its high ~8 vol.% of nanosized precipitates formed concomitantly with Cu clusters. Furthermore, the Nb influence on phase stability of this Heusler phase is elucidated through the study of precipitation kinetics. Overall, this work introduces a new design pathway for the development of ultra-high-strength steels by using the Heusler compounds, which benefit from a synergic effect of grain refinement and precipitation strengthening.
查看更多>>摘要：? 2022 Elsevier B.V.In this work, TiN/TiON nanotubes are developed by 3 step anodization of titanium sheet and facile plasma nitriding process of TiO2 nanoarrays in a PECVD reactor as a supercapacitor electrode. The plasma chamber temperature was changed to find the best nitrogen doping condition to increase electrical conductivity and areal capacitance. Also, the plasma temperatures were 450, 550, and 650 °C. X-ray diffraction (XRD) indicates the TiN peaks at 2θ= 37°, 43.2°, 62.2°, 47.6°, and 78.6° when the substrate temperature arrives at 650 °C. Raman spectroscopy was used to evaluate the phase and structure of nitrided samples when the electron microscopy analysis showed the unchanged morphology of TiO2 nanotubes before and after nitriding. XPS spectra of the plasma nitrided sample at 650 °C show the presence of oxynitride and nitride on the surface of nanotubes. So, the highest nitrogen incorporation in the TiO2 structure occurs at 650 °C. Also, electrochemical investigations showed an areal capacitance of 35.14 mFcm?2 for plasma nitrided electrode at 650 °C that represents 9 times more capacity than annealed TiO2 electrode (3.82 mF cm?2). Moreover, the novel plasma nitrided electrode has also indicated superior rate capability (80%) and cycle stability with low degradation of about 15% after 6000 cycles.
查看更多>>摘要：? 2022 Elsevier B.V.In-situ 5 wt% TiB2/Al-4.5Cu-0.4Mn composites were successfully prepared via the salt-metal reactions, which were assisted by improved mechanical stirring. The morphologies of the TiB2 particles in the matrix of Al-4.5Cu-0.4Mn were investigated using field emission scanning electron microscopy (FESEM). The results indicated that TiB2 particles were mainly present in the morphology of small plate-like hexagonal prisms, with size ranging from 0 to 1.4 μm and thicknesses of 0–0.8 μm. The growth mechanism of the TiB2 and the influence of the Mn on that mechanism were also discussed based on fundamental crystal growth theories. It was found that the Mn affected the growth of the TiB2 from the following two aspects: (1) The TiB2 particles were relatively small overall, due to the fact that the Mn could inhibit the diffusion of Ti and B atoms; (2) The Mn was preferentially adsorbed on {0001}, {101?0} and {101?1}, which tended to effectively inhibit the growth of those faces. A lower-energy state of the TiB2 particles with plate-like hexagonal prism morphology was retained in the Al-4.5Cu-0.4Mn alloy. Furthermore, the effects of the TiB2 particles on the tensile strength and elongation of the Al-4.5Cu-0.4Mn alloy were examined.
查看更多>>摘要：? 2022 Elsevier B.V.The lithium dendrites growth in Li7La3Zr2O12 (LLZO) solid electrolytes has severely restricted the development of all-solid-state lithium batteries. Herein, two different dynamic properties interlayers of electronically conductive Al and an electronically non-conductive Al2O3 are constructed at the Li/LLZO interface, and the lithium dendrite growth mechanism is explored. Results show that battery with Al interlayer occur internal short circuit in 95 cycles, while the battery with annealed Al2O3 interlayer has good cycle stability of 1000 cycles with polarization voltage below 0.1 V. Besides, dendritic lithium dendrites can be clearly observed at the LLZO grain boundaries of battery with Al interlayer. Raman and XPS results show that the Al2O3 interlayer reacts with Li+ during the charge and discharge process to form a Li-Al-O compound which is Li+ conductive. It is concluded that the lithium dendrite inhibition mechanism of the Li-Al-O compound interlayer is that it can promote the Li+ conduction from LLZO to lithium anode to undergo a lithium deposition reaction, and prevents electrons from conducting to LLZO and combine with Li+ to occur lithium dendrite growth. While for the Al interlayer, electrons can reach LLZO through the interlayer to combine with Li+ thus occurring the lithium dendritic growth.
查看更多>>摘要：? 2022 Elsevier B.V.Bismuth Telluride (Bi2Te3) is considered as a favorable thermoelectric compound. Currently, this compound has achieved a lot of interest in sensors, chip spots, thermoelectric generators and solar cells. The doping process of some elements into Bi2Te3 based alloy is an important method for the efficiency improvement of thermoelectric devices. However, the development of high-quality devices creates a lot of challenges for researchers. Hence, this paper provides a review of different aspects of doping processes on Bi2Te3 based materials, problems and the promising ways for solving the challenges. It was concluded that doping process, annealing of specimens and creation of nanostructured compounds result in the efficiency improvement of Bi2Te3 based thermoelectric materials. Besides, it was clarified that Bi2Te2.7Se0.3 and Bi0.5Sb1.5Te3 as thin films and bulk materials are two thermoelectric compounds produced by Se and Sb doping into Bi2Te3 based materials with high figure of merit (ZT). The research indicated that thin film Bi2Te2.7Se0.3 and Bi0.5Sb1.5Te3 materials show the highest ZT values versus other materials.
NSTL
Elsevier