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The nonradiative recombination of charge carriers at the hole transport layer (HTL)/perovskite interface generally induces remarkable performance loss of the inverted two-dimensional perovskite solar cells (2D PSCs). Herein, a cross-linkable small molecule of 2-mercaptoimidazole (2-MI) was introduced into the nickel oxide (NiOx)/2D perovskite interface. Experiments have confirmed the formation of Ni-N covalent bond by N atom in the 2-MI and Ni in the NiOx and the coordinating between S atom of 2-MI and under-coordinated Pb2+ near to the NiOx/perovskite interface, which contributes to creating a cross-linking between NiOx/perovskite interface to restrain charge carrier recombination and enhance the extraction of hole carriers at the interface. Besides, the 2-MI modification layer is also beneficial for promoting the crystallinity of 2D perovskite. Consequently, the inverted 2D PSCs with 2-MI modification achieved the best power conversion efficiency of 15%. This paves a route to acquire highly efficient 2D PSCs by constructing a cross-linking at the NiOx HTL/2D perovskite interface.

As an excellent promising tritium breeding material, Li2TiO3 ceramic pebbles will be required in large quantities in the future. For this reason, a fully automatic pneumatic eject device based on an improved wet process was employed in the mass-preparation of Li2TiO3 ceramic pebbles. The operating principle of the equipment, the preparation process parameters and the performance of the Li2TiO3 ceramic pebbles have been studied. The results showed that the spheroidization and solidification process of slurries droplets in the molding medium were critical to the sphericity of pebbles, and the size of the green pebbles was related to the droplet dropping speed、the control pressure and the nozzle inner diameter. It is revealed that more than 90% of the pebbles had an eccentricity of less than 1.1, and the diameter distribution was concentrated between 0.98 mm and 1.03 mm. The Li2TiO3 ceramic pebbles with the average grain size of 3.7 μm, the crushing load of 67 N, the relative density of 85.6%, and the porosity of 19.96% can be obtained after sintered at 1100 °C for 2 h. Also, the average pore size was 1.3 μm and the distribution was relatively concentrated. Therefore, this method is expected to meet the future demands of Li2TiO3 ceramic pebbles with excellent performance in bulk quantity.

Magnetic particles (MPs) are the most widely used commercialized engineering particles, which gained great success in various biological applications. Inspired by their intrinsic Fe isotope composition, we discovered a commercialized MPs-internal standard's novel function to realize the accurate quantification of biomolecules. The bioassay of carcinoembryonic antigen (CEA) was chosen as a modal system. The Fe isotope in MPs and Au isotope in report probes were simultaneously and sensitively detected by the elemental mass spectrometry. 197Au/57Fe isotopic ratios and CEA concentrations showed good linearity in the range of 0.6–300 ng/mL, with a detection limit of 0.09 ng/mL (3σ). The accuracy and precision of the proposed MPs-based immunoassay were greatly improved, by eliminating potential MPs loss during magnetic separation and absolute intensity fluctuations. Considering the exceptional availability and universality of commercialized MPs, the proposed method might open a new avenue for MPs' biological applications.

Palladium (Pd)-catalyzed cross-coupling reaction is a widely studied process with significant economic interest and represents one of the most successful nanocatalytic examples. Owing to the observ...

Efficient separation of blood cells and plasma is key for numerous molecular diagnosis and therapeutics applications. Despite various microfluidics-based separation strategies have been developed, a simple, reliable, and multiplexing separation device that can process a large volume of blood is still missing. Here we show a microbead packed deformable microfluidic system that can efficiently separate highly purified plasma from whole blood as well as retrieve blocked blood cells from the device. Combining microscope imaging, optical tomography scanning, and computational fluidic modeling, a highly accurate model is constructed to understand the link between the mechanical properties of the microfluidics, flow rate, and microbeads packing/leaking, which supports and rationalizes the experimental observations. This deformable nano-sieve device establishes a key technology for centrifuge-free diagnosis and treatment of bloodborne diseases and may be important for the design of next-generation deformable microfluidics for separation applications.

Wide-bandgap (WBG) perovskites play a crucial role for top cells in tandem solar cells (TSCs), which provides a promising avenue to boost the performance of widely used commercial solar cells. However, such WBG perovskite solar cells (PSCs) show poor performance compared to that of ~1.6 eV bandgap PSCs due to high defects density and photo-instability, resulting in relatively large open-circuit voltage loss (Vloss). Herein, we introduce alkali pseudo-halide KBF4 into the perovskite precursor solution for preparing less-defect WBG perovskite film. It is showed that the interstitial occupancy of K+ in the perovskite lattice and the suppression of recombination by BF4−, thereby inhibiting the ion migration and reducing the trap density. As a result, the champion WBG PSC (Energy gap (Eg), Eg = 1.74 eV) delivers a high open-circuit voltage (VOC) of 1.21 V and a power conversion efficiency (PCE) of 17.49%. This work provides new insight into the defect tolerance upon metal pseudo-halides doping in the WBG perovskite.

MnO2-based aqueous Zn-ion batteries (ZIBs) hold great promising for large-scale energy storage applications owing to their safe and sustainable nature. However, rapid capacity decay under high depth of discharge limits the applications of MnO2 cathodes. In the meantime, the reaction chemistry and degradation process of MnO2 cathodes cannot be fully understood, leading to improvement of their cycling stability lacks of robust methods. Herein, ZIB performances of MnO2 polymorphs are investigated to disclose their detailed reaction chemistry and degradation mechanisms. Ex situ characterizations at different cycles exhibit evolution of active materials (original MnO2→Mn2+→birnessite→ZnMn2O4/Mn3O4) and coexisted reactions from co-insertion, dissolution/deposition and chemical conversion mechanisms. Variational contributions from these intermediate products and different reaction mechanisms cause fluctuated performance during cycling. Initial performance activation is from enhanced activity of birnessite, while the degradation is caused by its conversion to electrochemically inactive ZnMn2O4 and Mn3O4. By optimizing tunnel structures, it is found that R-MnO2 shows low manganese dissolution with its reaction mainly achieved by intercalation/extraction of Zn2+/H+, and theoretical calculations verify its low Jahn-Teller distortion at discharged state. This specific property circumvents conversion of R-MnO2 to metastable birnessite, giving rise to a stable capacity under high depth of discharge.

The development of high-performance electrocatalysts for hydrogen evolution reaction (HER) is of great significance for green, sustainable, and renewable energy conversion. Herein, we report the synthesis of amorphous Ru clusters on Co-doped defect-rich hollow carbon nanocage (a-Ru@Co-DHC) as an efficient electrocatalyst for HER in the basic media. Due to the advantages such as high surface area, rich edge defect, atomic Co doping and amorphous Ru clusters, the as-made a-Ru@Co-DHC displays an efficient HER performance with a near-zero onset overpotential, a low Tafel slope (62 mV dec−1), a low overpotential of 40 mV at 10 mA cm−2 and high stability, outperforming the commercial Ru nanocrystal/C, commercial Pt/C, and other reported Ru-based catalysts. This work provides a new insight into designing new metal doped carbon nanocages catalysts supported by amorphous nanoclusters for achieving the enhanced electrocatalysis.

In order to investigated the influence on the liquid cooling system cooling effect by changing the structural parameters, single Li-ion battery heat generation model is conducted, and used in following simulation. Subsequently, sixteen models are designed by orthogonal array, and the results are obtained by extremum difference analysis, which can quantify the influence degree, identify major and minor factors, and find the relatively optimum combination. Finally, different channel entrance layout is adopted to investigated. With a series of work, the effective of single battery heat generation model is proved by the discharge experiment. The coolant velocity has most evident influence on the Li-ion battery temperature rise, rectangular channel aspect ratio is second one, and the heat conducting plate thickness has the smallest influence. Similarly, for Li-ion battery temperature difference, the effect of heat conducting plate thickness and rectangular channel aspect ratio as the same, both are secondary factor, and coolant velocity is main factor. With different channel entrance layout, both the maximum temperatures denote a same upward trend, and better balance temperature distribution is obtained by adopt Case C system which with alternating arrange channel entrance layout.

The cellular structured titanium alloys have attracted significant attention for implants because of their lower Youngʼs modulus, which is comparable to human bone and has the capability of providing space for bone tissue in-growth. However, there is a gap in the knowledge in regard to the relationship between the pore characteristics and the electrochemical performance of open-cellular structured titanium alloys. In this study, we elucidate the influence of pore characteristics on the electrochemical performance of open-cellular structured Ti-6Al-4V alloys produced by electron beam melting (EBM). Intriguingly, the passive film formed on cellular structured Ti-6Al-4V alloy with a larger pore size was more stable and protective, and the corrosion performance was superior compared to the samples with a smaller pore size in phosphate buffered saline (PBS), mainly because of relatively smaller exposed surface area and unlimited flow of electrolyte. However, in acidic PBS containing fluoride ions, the pore characteristics did not play an important role in the corrosion resistance. It was considered that the protective film breaks down such that the corrosion performance of cellular structured alloys was comparable to each other in this harsh environment.

Three A-π-A or D-π-D perylene diimide (PDI) derivatives with varied groups on π-conjugate were synthesized and characterized. The photophysical properties of these compounds were systematically studied by spectral experiments and density functional theory calculations. All compounds displayed intense absorption bands at 300-800 nm wavelengths. However, diverse groups on the π-conjugate influenced the UV-vis absorption. Electron-withdrawing groups on PDI-2 caused a slight red shift at the 350-400 nm wavelength and a blue shift after 400 nm wavelength. At the same time, the electron-donating substituents on PDI-3 caused an obvious red shift of this band. These PDI derivatives exhibited emission in solution at room temperature (λem = 500-850 nm). The quantum yield of PDI-3 decreased, while the electron-donating substituents were introduced to the π-conjugated motifs. However, the quantum yield of PDI-2 increased when electron-withdrawing substituents were introduced to the π-conjugated motifs. In addition, PDI-1 and PDI-2 exhibited broad triplet transient absorption in the visible region. These photophysical properties could help us to understand the relationship between structure and photophysical properties of perylene diimide derivatives and exploit more original perylene diimide-based optical functional materials.

Background Humans can recognize the physical properties of objects by touching them, even when vision is unavailable. Tactile perception is important for humans in interacting with the environment. The triangular ridged textures are usually added to surface to improve the grip reliability of products, but the sharp edge of triangular ridge induces sharp and uncomfortable feeling. Materials and methods To study the effect of the edge shape of triangular ridged texture on brain activity, functional magnetic resonance imaging technique was used to obtain the blood oxygen level-dependent (BOLD) signal of subjects during the touching of textured surfaces. Samples with sharp, round, and flat shape ridged textures were chosen as the tactile stimulus. Results The contralateral postcentral gyrus, the precentral gyrus, the inferior parietal lobule, and the supramarginal gyrus, corresponding with the functional regions of the primary somatosensory cortex (SI), the secondary somatosensory cortex (SII), and the primary motor cortex (MI) were related to the perception of three shape ridged textures. The main brain activation located in the postcentral gyrus and the SI. The tactile information of three shape ridged textures was received by Brodmann area (BA) 3 of the SI, and then inputted to BA 2 of the SI, the further tactile discrimination of shape of ridged textures was involved in BA40 of the SII. The intensity, the areas, and the percent signal change (PSC) of brain activation that were evoked by different shape ridged textures were related to the geometric structures of the ridged textures. The more complex the geometric structures of texture are, the larger the intensity, the area, and the PSC in brain activation are. The negative BOLD responses of the ipsilateral sensory cortex that were evoked by the flat ridged texture indicated the ipsilateral neuronal inhibition within the sensory systems. The bilateral precuneus, the superior parietal gyrus, and the inferior parietal gyrus, corresponding with the functional areas of the SII (BA40) and the SSA(BA7), were involved in the tactile discriminate of the differences in shapes of ridged textures. The differences in brain activation were related to the differences in geometric structures of the ridged texture. The larger the differences in geometric structure of texture are, the larger the differences in brain activation are. This study revealed the activated location of brain related to the tactile stimulation of different edge shape of ridged textures and the relationship between the geometric structures of ridged texture and brain activities. This research contributes to optimize surface tactile characteristics on products, especially effective surface textures design for good grip.

In this study, a heat pump drying (HPD) system platform complemented by solar hot water was designed and established. The objective was to address the declines in the heating performance of air source HPD at high altitudes (more than 3000 m), cold conditions (annual average temperature at 5 °C), and with large temperature differences between day and night (more than 20 °C), i.e. under harsh conditions. A theoretical model was derived to determine the system parameters and to support the experimental analysis. Under no-load conditions, four cases with ambient temperature were tested and compared to explore the relationships between the system parameters and performance, as well as the effectiveness of the supplementary solar hot water. The heating performances under HPD and solar-assisted HPD (SHPD) modes were compared and analysed under load conditions (930 kg Mu Xiang). The results indicate that a decrease in the ambient temperature and increase in the temperature in the drying room causes attenuations of the compressor mass flow rate, evaporator cooling power, condenser heating power, and system coefficient of performance (COP). In addition, solar water heating can significantly improve the heating performance of the HPD system. Under no-load conditions, the average heating power of the HPD-mode system is 19.27 kW, and the average COP is 2.76. The average heating power of the SHPD mode system is 23.34 kW, and the average COP of the system reaches 3.24, an increase of 17.4%. Under load conditions, the average heating capacity power of the HPD mode is 9.64 kW; the COP is only 1.34, and fluctuates significantly with the decrease in ambient temperature. The average heating capacity power of the SHPD mode is 17.62 kW and the COP is 2.42, i.e. 1.8 times of that of the HPD mode. By raising the drying room temperature to the same set temperature, the SHPD mode time is shortened by 70%.

This paper proposes a flexible strain sensor based on the principle of resistance sensing to estimate the curvature information of the soft pneumatic gripper. The proposed sensor mainly includes a spiral conductive fiber and a central elastic base pillar. The conductive fiber is made of the stretchable elastomer DragonSkin-30 and multi-walled carbon nanotubes (MWCNTs) mixture, and a customized platform is designed to perform extrusion for fabrication. Three essential factors of the substrate, the fiber diameter, and the mixing ratio of MWCNTs have been investigated to improve the sensitivity and strain range of the sensor. Ecoflex-10 with excellent tensile properties has been selected to make the elastic base pillar. The stretchability, linearity, and service life of the sensor were improved by optimizing the spiral arrangement of conductive fibers through experiments. The proposed approach for manufacturing and assembly offers the advantages of easy implementation, convenient integration, and low cost. The electrical performances of the prototyped spiral sensor have been characterized, and it can reach an excellent strain range of up to 400% with linearity of 98%. The prototype has been integrated on the outer surface of a soft pneumatic gripper and well reflected the diameters of the unknown objects with an error of 3.99% through calibration and grasp-release experiments.

Electrodeposition, which is an eco-friendly process with high efficiency, is one of the most promising technologies for metal recovery. However, the kinetics are often limited by the polarization and uncontrollable quality of deposits during the electrodeposition process, which restrict the efficiency and controllability of metal recovery. To ameliorate the limitations of the deposition rate and as-formed deposit quality, transient electrodeposition was introduced to control the microinterfacial reaction by regulating the relationship between charge and mass transfer. The Cu2+ removal efficiency and kinetic coefficient during 1 kHz transient electrodeposition were 17.4 and 17.7% higher than those under the conventional steady electric stimulus, respectively. Based on the combined results of X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDS), it was found that the chemical composition of the deposits from transient electrodeposition was more homogenous, as indicated by the low content of metal oxides. The in situ Raman spectra explained the homogenous composition based on the weak interaction of the electrode with the anions during the transient electrodeposition, which was mainly due to the enhanced dehydration under the oscillating or alternating electric field. The potential oscillation induced by the transient electric field also facilitated dehydration, charge transport, and mass transfer, which led to rapid and high-quality metal recovery. Transient electrodeposition will have a great guidance value in the field of metal electroplating and heavy metal recovery from wastewater by electrodeposition.

Called by Green Ship of the Future to reduce the propeller noise pollution in the subsea environment and avoid the possibility of causing propeller–shaft–ship resonance, the low-frequency broadband noise (LFBN) of marine propellers was studied theoretically and experimentally. The spectral method is improved by considering the blade section thickness and anisotropy in the turbulence spectrum, both of which are found to be effective in improving the prediction accuracy when compared with the experimental results. A series of propellers with the same blade geometry but different blade number were tested in the large cavitation channel at the China Ship Scientific Research Centre. The peak values in all conditions were close to the first-order blade-passing frequency. The effects of blade number and the advance coefficient were investigated by testing the propellers operating under different conditions. The effects were also studied using both the spectral method and experiment, and the results were consistent. Furthermore, the quantitative dependence of the LFBN on the influencing parameters was investigated using the sensitivity analysis. The rotational speed and turbulence intensity were found to be the two main factors, with greater than 10% effects. In addition, the effects of thickness and anisotropy scaling factor were evaluated using the spectral method. The results of this study provide guidance for controlling the LFBN in propeller design and optimisation.

Novel rare-earth-contained W-based in-plane chemically ordered (W2/3R1/3)2AlC (R = Gd, Tb, Dy, Ho, Er, Tm and Lu) i-MAX phases have been firstly reported. All are identified to be C2/c monoclinic by structural analysis. Magnetic ground state is found to change from linear antiferromagnetism for R = Gd to paramagnetism for R = Lu with gradually decreased ordering temperature with the evolution on magnetic configurations. By exfoliation and delamination, brittle W1.33C MXene fragments have been obtained and demonstrated undesired specific capacitance of 76 F g−1 at 1 A g−1. By making W1.33C/Ti3C2 composite MXene, flexible free-standing paper has been obtained and the specific capacitance is substantially enhanced to 183 F g−1 with good retention, which is the highest performance realized in W1.33C MXene up to now.

Carbon dots (CDs) are synthesized by the solvothermal method with four kinds of solvents including water, dimethylformamide (DMF), ethanol, and acetic acid (AA). The aqueous solutions of the above CDs emit multiple colors of blue (470 nm), green (500 nm), yellow (539 nm), and orange (595 nm). The structures, sizes, and chemical composition of the CDs are characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS). The optical properties of multicolored CDs are analyzed by UV–vis absorption and photoluminescence (PL) spectra. It has been revealed that DMF is the key solvent to synthesized CDs for the red shift of fluorescence emission, which could be enhanced by adding an AA solvent. The structures of functional groups such as the contents of graphitic N in carbon cores and oxygen-containing functional groups on the surface of CDs are affected by these four solvents. According to the oxidation and selective reduction of NaBH4, the implication for multicolor imaging has been discussed based on the COOH, C–O–C, and C=O functional groups.

In this work, dynamic pH-sensitive quick response code (QR code) labels have been successfully fabricated by inkjet-printing technology. Inks with roselle anthocyanins and curcumin natural dye are prepared, respectively. The rheological property, contact angle, and surface tension of the prepared inks are tested. Both inks show good printability with Newtonian fluid property. The QR code labels with different ratios of inks are fabricated, in which the ink ratio is controlled by automatic computer program. It can be seen that the color of all printed QR code labels is sensitive to the concentrations of ammonia solutions, demonstrating that the pH-sensitive QR code labels are achieved. The ammonia-dependent color difference is analyzed by L*a*b* digital images. It can be found that the color difference strongly depends on the ink ratio, which suggests that the QR code labels with different ink ratios can be applied for diverse food freshness monitoring in real time. Therefore, in future, combined with the QR code application program (QR code APP) of intelligent devices, the developed QR code labels can be used as data carrier and freshness sensor as well, which provides a convenient method to get comprehensive food information, including freshness, expected storage time, date and identification of product, etc.

Force-chain is the main load-bearing structure in the granular materials. The study of force chains and particle breakage is of great significance to understand the mechanical properties of the granular materials. At present, the internal relationship between the force chains and particle breakage is still unclear. It also has no idea about the crushing mode of the particle system with complex gradation and stress path. Therefore, in the present paper, the continuous-discontinuous numerical method (Numerical Manifold Method, NMM) is utilized to simulate the process of the force chains generation and particle breakage in granular material and to explore their internal connection mechanism. The simulation results show that the particle breakage is directly related to the force-chain network, and the particle breakage morphology is basically consistent with the direction of the force-chain network in the granular system. Small particles are broken firstly, producing large displacement to fill the voids in the system. Although the larger particles can also be broken, it is difficult to produce large displacement due to the influence of coordination number among particles. Furthermore, particle breakage can reduce the strength of the force-chain, resulting in that the larger particles in the force-chain will be broken slightly or not.

In this study, the influence of Fe doping on the microstructure and mechanical properties of Gd–Al–Co “metallic glass” fibers (MGF) was systematically investigated, and a fracture mechanics model was constructed based on the fracture morphology of MGF. Furthermore, the mechanism by which Fe doping improves the mechanical properties was revealed. The results indicate that the Gd–Al–Co–Fe series MGF has a typical amorphous structure, and with an appropriate amount of Fe increases the order degree of structure ψ, indicating that a small number of nanocluster micro-regions are formed on the amorphous matrix. With an increase in Fe doping, the tensile strength of MGF presents an initial increase and subsequent decrease. The tensile strength, Rm, of the GdAlCoFe2 MGF was the largest (up to 1199 MPa), and its fracture reliability was also superior (the threshold value of fracture was 581.93 MPa). The tensile fracture of the Gd–Al–Co–Fe series MGF is a flat fracture, showing the characteristics of brittle fracture, with vein-shaped patterns, splitting, and shear bands. A specific amount of nanocluster micro-regions formed by Fe doping effectively hindered the growth rate of crack tips during the stretching and deformation of the microfibers, and significantly improved the mechanical properties of the Gd–Al–Co–Fe series MGF. This study lays the foundation for its engineering applications in the fields of mechanics and machinery.

Lithium-sulfur (Li-S) batteries have attracted considerable attention due to their advantages, such as high specific capacity, high energy density, environmental friendliness, and low cost. Therefore, Li-S batteries are one of the most promising electrochemical energy storage systems. However, the practical application of Li-S batteries is limited by some severe faults, such as the dissolution and migration of polysulfides, the insulation and volume expansion during the cycling of elemental sulfur. Considerable research efforts have been dedicated to solving these difficulties from every parts of Li-S batteries, including separators. By rationally designing and optimizing of separators, the reversible capacity, coulombic efficiency, and cycling stability of the Li-S batteries can be effectively improved. This article mainly reviews the research progress of separator modification materials in Li-S batteries, and summarizes the methods and characteristics of separator modification including carbon materials, polymer materials, inorganic compound materials, metal organic framework, and covalent organic framework materials and other metal compounds. From the anode side, the mechanism through the modification of separators can help to stabilize lithium metal anode is also discussed. Finally, the perspectives and challenges of separator modification in Li-S batteries are pointed out.

The fluorescent molecule N,N-bis(3',5'–bis(trifluoromethyl)-[1,1'–biphenyl]-4–yl)perylen-3-amine (TFPA) was designed and synthesized by introducing the strong electron-withdrawing trifluoromethyl group and the strong electron-donating diphenylamino group, with perylene as the core. The structure of the target product was identified by nuclear magnetic resonance, and its UV–vis absorption properties, fluorescence emission properties, quantum yield and lifetime were studied systematically. The results showed that the HOMO of TFPA was mainly localized in the perylene part with a small part localized in the triphenylamine structure. The LUMO was almost localized in the perylene part. Therefore, the ground-state absorption of TFPA is mainly attributed to the π–π* transition accompanied by with little the slight intramolecular charge transfer effect. The maximum emission peak (534 nm) of TFPA in the solid state was 18 nm redshifted compared to that of TFPA in solution (516 nm). TG results show that TFPA still does not decompose at 300 ℃, indicating good thermal stability. In addition, a yellow-light-emitting diode device based on the fluorescent molecule TFPA was constructed (CIE coordinates: 0.45, 0.54). The LED device showed good color purity (color purity: 97.8%). The results showed that TFPA was a luminescent material with excellent thermal stability and high color purity and had potential for use in fabricating yellow LEDs.

An effective improvement of hydrogen evolution from water splitting under solar light irradiation was investigated using quantum dots (QDs) compounds loaded onto a Au/TiO2 photocatalyst. First, Au/TiO2 was prepared by the deposition-precipitation method, and then sulfide QDs were loaded onto the as-prepared Au/TiO2 by a hydrothermal method. QDs were loaded onto Au/TiO2 to enhance the energy capture of visible light and near-infrared light of the solar spectrum. The results indicated that the as-prepared heterojunction photocatalysts absorbed the energy from the range of ultraviolet light to the near-infrared light region and effectively reduced the electron-hole pair recombination during the photocatalytic reaction. Using a hydrothermal temperature of 120 °C, the as-prepared (ZnS–PbS)/Au/TiO2 photocatalyst had a PbS QDs particle size of 5 nm, exhibited an energy gap of 0.92 eV, and demonstrated the best hydrogen production rate. Additionally, after adding 20 wt % methanol as a sacrificial reagent to photocatalyze for 5 h, the hydrogen production rate reached 5011 μmol g−1 h−1.

In this work, c-axis-oriented continuous GaN films have been synthesized by the chemical vapor deposition (CVD) method using ZnO material as the intermediate buffer layer. The GaN films with different growth temperatures exhibit high crystal quality and small surface roughness due to the same crystal structure and low lattice mismatches rate between GaN and ZnO materials. Meanwhile, the UV photodetector based on the CVD-grown GaN film exhibits a relatively high responsivity, fast rise and decay time, and good thermal stability. Our work provides a simple and promising CVD method to fabricate continuous GaN film for electronic and optoelectronic devices.

At present, shale gas pressure fracturing volume development technology tends to be mature, shale gas backlog fracturing ends and enters the trial production stage. Due to the improper control of o...

Carbon (C) is major element of most hot springs, yet knowledge on carbonaceous compounds in hot springs and their role in the cycle of elements are limited. Here we analyzed carbonaceous compounds in Zibo hot springs, China, by electron microscopy and chemical analysis. Results display spherical and irregular C-bearing nanoparticles from 50 to 150 nm. Nanoparticles typically contain, in wt%, 40.4–77.6 C, 8.12–15.9 N, 4.27–13.8 O, 0.12–0.13 Mg, 1.47–2.67 Si, 0.09–0.16 S, 0.04–0.20 Cl, and 0.63–34.7 Fe. These findings reveal the occurrence of C nanoparticles in hot springs, accompagnied by several other elements. The biophilic elements N and Fe and biomimetic morphology of nanoparticles suggest a biological origin. We discuss implications for carbon cycling and for the possible use of C-bearing nanoparticles to prospect geothermal resources in the deep Earth.

With the purpose of oil energy recovery as well as achieving efficiency of oil/water separation, hydrophobic mesh materials have attracted extensive attention. However, fabrication of the current methods is not environmentally friendly, has high energy consumption, and creates serious pollution. Inspired by lotus leaves and rose petals, a biomimetic superhydrophobic surface was fabricated prepared on a stainless steel mesh by an in situ chemical reduction method with simple operation and mild conditions. The results of SEM, XRD, and XPS demonstrated that the mesh shows a stable and uniform moss-like rough structured surface. The SSM/Ag/ODA mesh, which was modified by moss-like Ag nanoclusters and low surface energy agents, has excellent superhydrophobicity with an excellent oil/water separation efficiency that reached up to 99.8%. The silver mirror phenomenon formed by the Ag nanoclusters further confirmed that silver ions were reduced and attached to the surface of the mesh. Moreover, the mesh can maintain superhydrophobicity under harsh conditions, such as a high concentration of a salty solution, organic solvents, alkaline, acidic solution, and even long-time UV irradiation, etc. More importantly, the modified mesh has excellent physical stability, in which the water contact angle on the mesh can be maintained above 150° after harsh mechanical wear. The hydrophobic mesh showed great potential to be applied for highly efficient oil/water separation and oil energy recovery even under complex and harsh conditions.

The Haber-Bosch N2 fixation method suffers from the power-consuming and harsh conditions. In contrast, the electrochemical conversion of N2 (NRR) at room temperature and atmospheric pressure is considered a promising alternative route. In this study, we synthesized Sb-modified with Bi25FeO40 (BFSO/BFO) by using one-step hydrothermal treatment. The BFSO/BFO catalyst has higher selectivity to NRR than Bi25FeO40 (BFO) under the same applied voltage. Such large interfacial interaction area plays a critical role in transfer electron and enhances the density of current. The resulting BFSO/BFO heterojunction showed significant electrocatalytic activity under controllable voltage, which exhibited favorable average ammonia (NH3) yield as high as 2.62 μg·h−1·cm−2 at −0.2 V versus RHE. Moreover, the stability of the BFSO/BFO composite was evaluated for six cycles and the results were desirable. This study provides a new insight into the design of composite catalysts using BFO, which has high activity and selectivity toward NRR.

MXene is a neoteric type of bidimensional (2D) transition metal carbide/nitride with broad application prospects, in particular with electrochemical energy storage. The electrochemical performance of MXene is unsatisfactory because it is easy to stack resulting in the difficulty of electrolyte penetration and ion transport. In this study, the cobaltous sulfide-modified 3D MXene/N-doped carbon foam (CoS@MXene/CF) hybrid aerogel is projected and manufactured via simple in situ growth and thermal annealing strategies. The capacitance of the as-fabricated 300-CMC-31:1 electrode material reaches 250 F g-1 (1 A g-1), which is obviously higher than those of MXene, CoS@CF, 400-CMC-31:1, 300-CMC-10:1, 300-CMC-50:1, CF, and MXene/CF electrode materials. Moreover, it can hold 97.5% of the original capacitance after 10,000 cycles and the internal resistance (Rs) is only 0.50 Ω. A green bulb can be lit by two all-solid asymmetric supercapacitors installed in series. The prepared CoS@MXene/CF hybrid aerogel exhibits promising potential for practical application in energy storage areas.

As a famous hole transporting material, nickle oxide (NiOx) has drawn enormous attention due to its low cost and superior stability. However, the relatively low conductivity and high-density surface trap states of NiOx severely limit device performance in solar cell applications. Interfacial engineering is an efficient approach to achieve remarkable hole-transporting performance by surface passivation. Herein, the efficient NiOx hole transport layer was prepared by surface passivation engineering strategy via facile solution processes with cesium iodide (CsI). It is demonstrated that CsI plays a super-effective dual-function role in inverted solar cell device: On one hand, the presence of CsI hugely passivates the surface trap states at the NiOx/perovskite interface along with obviously improved conductivity by the incorporated Cs+; on the other hand, the ions immigration is significantly suppressed by the presence of I ion for high-quality perovskite films, resulting in a stable contact interface. The ameliorative interface leads to largely reduced carrier non-radiative recombination, attributing to boosted carrier extraction efficiency. As a result, decent power conversion efficiency (PCE) of 18.48% with a noticeable fill factor (FF) beyond 80% was achieved. This facile and efficient surface engineering approach with dual-function shows excellent potential for the design of high-performance functional interfacial modification layer to achieve high-performance solar cells.

Rapid screening monofluoroacetic acid (FAcOH) is responsible for preventing chemical poisoning and food safety events. Whereas surface enhanced Raman scattering (SERS) spectra is an effective tool for detecting forbidden chemicals, it is difficult to directly detect FAcOH due to its small Raman scattering cross section as well as weak adsorption on SERS substrates. In this work, the metal phenolic supramolecular networks (MPNs, i.e., the tannic acid and Fe3+ complex) were fabricated on the commercial nanoanodic aluminum oxide film (NAAO) for assisting in situ chemical deposition highly uniform Ag nanostructure over large areas (the NAAO@AgNS). The low cost and simple fabrication process made the NAAO@AgNS a single-use consumable. For FAcOH detection, a specific derivative reaction between FAcOH and thiosalicylic acid (TSA) was introduced. By taking TSA as the Raman probe, its SERS signal attenuated constantly with the increasing amount of FAcOH. For improving quantitative accuracy, thiocyanate (SCN-) was introduced on the NAAO@AgNS as an internal standard; thus, the characteristic peak intensity ratios associated with TSA and SCN- (I1035/I2125) were fitted to the concentration of FAcOH. It was demonstrated that the SERS assay achieved good sensitivity and selection toward FAcOH with the limit of quantitation (LOD) as low as 50 nmol L-1. The NAAO@AgNS featured with highly sensitive, uniform, and consistent SERS performances could easily extend to wide SERS applications.

Rechargeable magnesium batteries (RMB) are one of the utmost promising post-lithium energy storage technologies due to their high theoretical energy density, affordable low cost, and inherent safety with moisture and air. Nonetheless, the research of RMB has been limited due to the low power and reversible energy densities of available cathode materials. Herein, we report a new Mg battery cathode of trigonal Na5V(PO4)2F2 (t­-NVPF) which performs 136 mA h g−1 reversible capacity realizing multi-electron storage through the V4+/V3+ and V5+/V4+ redox couples. After the first reversible cycle MgNa3V(PO4)2F2 is formed. The geometry optimization and energy calculations on the systems MgxNa3V(PO4)2F2 were carried within the density functional theory (DFT) demonstrating Mg insertion can fill the Na6, Na8, and Na9 sites, and evidenced a 1.5 V difference for the same redox couple comparing with the experimental results. Some facets of its crystal and local structure are determined by XRD, EPR, XPS, and 31P and 51V solid-state NMR spectroscopy. The cells cycled 2.5 – 0.2 V vs. Mg2+/Mg and at low current densities exhibited diminished polarization. The average cell potential is 1.4 V, entailing an energy density of 190 W h kg-1­ at the materials’ level. This piece of work provides an effective strategy for designing multi-electron storage for high-energy rechargeable Mg batteries, but more efforts are required to overcome high polarization during charge-discharge cycles which are commonly found in Mg batteries.

The preparation of atomically dispersed catalysts with high metal loading remains a formidable challenge due to the high surface energy of single atoms. Here we prepared PtPd/TiO2 catalysts possessing metal loading as high as 8.17 wt% by a new versatile method which based on metal oxide carriers with abundant oxygen defects. PtPd/TiO2 catalysts consist of PtPd nanoparticles and atomically dispersed Pt and Pd atoms, and the content of PtPd nanoparticles is little. Pt3Pd1/TiO2-400 catalyst exhibited the highest catalytic activity in toluene oxidation, and with a 94.7% conversion at 110 °C. Kinetic investigation reveals that the toluene oxidation follows a typical Langmuir-Hinshelwood mechanism. Experimental research indicates that the superior catalytic activity could be attributed to a large number of metal atoms atomically dispersed on the surface of the catalyst. Pt and Pd atoms are close to each other, which produces the synergetic effect and thereby promotes toluene oxidation. This work provides a promising pathway to fabricate single atom catalysts with high loading.

The effects of Cl−, Cu2+ and Fe3+ ions and their combinations on the corrosion behaviour of aluminium alloy 6063 (AA6063) in ethylene glycol and water solutions at 50 °C were investigated by electrochemical and immersion methods. Cl− resulted in pitting corrosion of the alloy. In the Cl−-free solutions, Fe3+ was prone to accelerate uniform corrosion, while Cu2+ tended to accelerate pitting corrosion. Severe pitting corrosion of AA6063 was observed in the cases of Cl− combined with Cu2+ or Fe3+, especially in the case of Cl− combined with Cu2+ and Fe3+ ions.

Properties of polymer products are determined by their microscopic structures. Dynamic Monte Carlo (DMC) simulation is a powerful tool to capture detailed polymer microstructures. However, the heav...

Although ceria-based catalysts serve as an appealing alternative to traditional V2O5-based catalysts for selective catalytic reduction (SCR) of NOx with NH3, the inevitable deactivation caused by SO2 at low temperatures severely hampers the ceria-based catalysts to efficiently control NOx emissions from SO2-containing stack gases. Here, we rationally design a strong sulfur-resistant ceria-based catalyst by tuning the electronic structures of ceria highly dispersed on acidic MoO3 surfaces. By using Ce L3-edge X-ray absorption near edge structure spectra in conjunction with various surface and bulk structural characterizations, we report that the sulfur resistance of the catalysts is closely associated with the electronic states of ceria, particularly expressed by the Ce3+/Ce4+ ratio related to the size of the ceria particles. As the Ce3+/Ce4+ ratio increases up to or over 50%, corresponding to CeO2/MoO3(x %, x ≤ 2.1) with the particle size of approximately 4 nm or less, the non-bulk electronic states of ceria appear, where the catalysts start to show strong sulfur resistance. This work could provide a new strategy for designing sulfur-resistant ceria-based SCR catalysts for controlling NOx emissions at low temperatures.

To understand the dispersion behavior of metal oxides on composite oxide supports and with the expectation of developing more feasible catalysts for soot oxidation, CuO/La2Sn2O7 samples containing varied CuO loadings were fabricated and characterized by different techniques and density functional theory calculations. In these catalysts, a spontaneous dispersion of CuO on the La2Sn2O7 pyrochlore support formed, having a monolayer dispersion capacity of 1.90 mmol CuO/100 m2 La2Sn2O7 surface. When loaded below this capacity, CuO exists in a sub-monolayer or monolayer state. X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Bader charge and density of states analyses indicate that there are strong interactions between the sub-monolayer/monolayer CuO and the La2Sn2O7 support, mainly through the donation of electrons from Cu to Sn at the B-sites of the structure. In contrast, Cu has negligible interactions with La at the A-sites. This suggests that, in composite oxide supports containing multiple metals, the supported metal oxide interacts preferentially with one kind of metal cation in the support. The Raman, in situ diffuse reflectance infrared Fourier transform spectroscopy, and XPS results confirmed the formation of both O2– and O22– as the active sites on the surfaces of the CuO/La2Sn2O7 catalysts, and the concentration of these active species determines the soot combustion activity. The number of active oxygen anions increased with increase in CuO loading until the monolayer dispersion capacity was reached. Above the monolayer dispersion capacity, microsized CuO crystallites formed, and these had a negative effect on the generation of active surface oxygen sites. In summary, a highly active catalyst can be prepared by covering the surface of the La2Sn2O7 support with a CuO monolayer.

Perovskite solar cells (PSCs) have been attracting tremendous attention due to ease of processing, flexibility, and high performance. Dimethyl sulfoxide (DMSO) and N, N-dimethylformamide (DMF) are the two most widely used solvents to dissolve perovskite precursors. Here, we investigate the impact of residual amount and evaporation rate of the DMSO inside the precursor films on the microstructure of the ultimate perovskite films. We decouple the DMSO and DMF solvents and demonstrate that DMSO component exhibits great and dominant influence on the final film morphology by using quasi in-situ photoluminescence (PL) measurement and X-ray diffraction (XRD) characterization of the wet films after spin-coating. Much more smooth and uniform perovskite films are obtained by careful management of remanent solvent, including decreasing residual amount by shelving the precursor films prior to heating and retarding the evaporation of the solvent via adopting a gradient annealing (GA) process. In consequence, the as-prepared PEDOT: PSS-based inverted PSCs yield a champion efficiency of 15.59% with high reproducibility. This work shows great potential in preparing high-quality perovskite films through a simple remanent solvent management engineering.

Thermal modification reduces the hygroscopicity of timber potentially reducing susceptibility to biological degradation, but it is also energetically intensive. Identifying methods for accelerating the process could reduce these inputs. The potential effects of glycerol pretreatment on thermal modification was investigated by pre-treating poplar wood (Populus tomentosa Carr.) with 60% glycerol followed by thermal modification at temperatures between 120 and 200 °C for 4 h. Potential changes in the wood were analyzed using high performance liquid chromatography, infrared spectroscopy, X-ray diffraction, scanning electron microscopy and fluorescence microscopy to detect the changes in cell wall components, crystallinity, the average size of the crystalline region and cell wall thickness. Glycerol accelerated lignin decomposition over the entire temperature range. Thermal modification altered the degree of cellulose crystallinity as well as the average size of the crystalline region and the effects were more noticeable with the glycerol pre-treatment. The cell wall thickness of thermally treated wood decreased with increasing temperature and glycerol accelerated this process. Glycerol appears to enhance the modification process with increasing treatment temperature.

Microfluidic chips made by traditional materials (glass and silicon) are still important for fluorescence tests, biocompatible experiments, and high temperature applications. However, the majority of the present bonding methods suffer from ultra-clean requirement, complicated fabrication process, and low production efficiency. In the present work, an Electrohydrodynamic printing assist bonding method was proposed. By this method, the ultraviolet-cured-glue dots were printed onto the silicon substrate, and then the patterned glass and silicon substrate can be bonded together at room temperature. The influence of printing condition (nozzle inner-diameter, applied voltage, printing height, and flow rate) on the diameter of printed dot was analyzed by experiments. By the optimized printing condition, the glass-silicon microfluidic chip can be well bonded. The bonding strength and leakage test demonstrated the high bonding quality of the microfluidic chip (bonding strength of 28 MPa and leakage pressure of 3.5 MPa).

Selective laser melting (SLM) tungsten (W) constantly suffered from severe cracking phenomenon due to the high melting temperature and low intrinsic ductility of W material. To address this significant issue, active ZrC nanoparticles were introduced into the W matrix to form ZrC/W composites in situ by SLM to enhance the intrinsic toughness of W in this study. It mainly focused on the effect of ZrC nanoparticle on the microstructure and cracking behavior of SLM W. Compared to SLM W, SLM ZrC/W composites showed finer equiaxed grains rather than columnar grains, because the ZrC nanoparticles provided many heterogeneous nucleation sites. Furthermore, ZrC nanoparticles could react with oxygen impurity at the grain boundaries (GBs), and then form stable ZrO2 and ZrW2O8 to purify and improve the cohesion strength of GBs. The columnar to equiaxed transition (CET) of grains and purified GBs played an important role in inhibiting the formation and propagation of the cracks in SLM W. Therefore, SLM ZrC/W composites exhibited lower crack density and higher mechanical properties compared to SLM W. This study provides a novel approach for suppressing the cracking susceptibility of SLM W.

A flexible temperature sensor based on poly-(3, 4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) with isopropyl alcohol (IPA) treatment is successfully fabricated by screen printing. The distribution of PEDOT is investigated by the SEM, AFM, and Raman techniques. It can be found that the microstructure is manipulated by the ratio of the PEDOT:PSS to IPA content. Raman spectra demonstrate that the transition between quinoid and benzoid structures of PEDOT are tuned by IPA treatment as well. The temperature dependence of resistance for IPA-treated PEDOT:PSS film is found to be well fitted by non-adiabatic small polaron hopping transport. Moreover, a constant temperature coefficient of resistance (TCR) value can be obtained by the optimized ratio of IPA to PEDOT:PSS. Therefore, this paper suggests that the tuned microstructure of PEDOT:PSS film can be realized by IPA treatment, which plays an important role in the physical properties of the temperature sensor based on PEDOT:PSS.

The stresses around bubbles formed on a coating/substrate interface under hydrostatic pressure (HP) and alternating hydrostatic pressure (AHP) were calculated using the finite element method. The results reveal that HP promotes coating failure but does not mechanically destroy the interface, whereas AHP can provide tensile stress on bubbles formed at the interface and accelerate disbonding of the coating. Because of water resistance, a lag time exists for the coating that serves in an AHP environment. The coating can have a better protective performance if the lag time suits the AHP to minimize the impact of the AHP on the interface.

Cataluminescence is an attractive oxydic luminescence on the gas-solid interface, and metal-oxide@MOF core@shell architectures show great potential for cataluminescence sensing due to their integrated synergistic effect from core and shell components. However, restricting the direct nucleation and growth of metal-organic frameworks (MOFs) on the topologically distinct surface of metal oxides is a great challenge, owing to the high interface energy from the topology mismatch. Herein, for the first time, a novel liquid-phase concentration-controlled nucleation strategy is exploited to induce the direct assembly of a ZIF-8 layer on the surface of CeO2 nanospheres without any sacrificial templates or further surface modifications. The results show that the construction of the CeO2@ZIF-8 core@shell architecture can be accomplished within 1 min under the mediation of boosted nucleation kinetics. Furthermore, the universality of this developed strategy is demonstrated by the encapsulation of other metal-oxide cores such as magnetic Fe3O4 and ZnCo2O4 core particles with a ZIF-8 shell. Notably, compared to the pure CeO2 and ZIF-8, the obtained CeO2@ZIF-8 nanocomposite exhibits enhanced analytical performance for the cataluminescence sensing of propanal, in which the shell acts as the major catalytic reaction center, while the core contributes to further improving the catalytic efficiency. The proposed facile synthesis strategy with excellent simplicity, rapidity, and universality brings new insights into the engineering of core@shell advanced functional materials with mismatched topologies for catering to the diverse application demands.