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Carbon nanotube-based (CNT-based) interfacial evaporation material is one of the most potential materials for solar desalination. Here, we studied the evaporation rate of the CNT-based membranes with different hydrophilic and hydrophobic chemical modified surfaces using molecular dynamic simulations. We found that the hydrogen bonding density among water molecules at the interface is a key factor in enhancing the evaporation rate. For a hydrophilic CNT-based membrane, the strong interactions between the membrane outer surface and the water molecules can destroy the water-water hydrogen bonding interactions at the interface, resulting in the reduction of the hydrogen bonding density, leading to an enhancement effect in evaporation rate. We also found that there is an optimal thickness for evaporation membrane. These findings could provide some theoretical guidance for designing and exploring advanced CNT-based systems with more beneficial performance in water desalination.

Well-ordered hierarchically mesoporous/microporous carbon materials have been successfully fabricated by using dual soft-templating approach through compressed CO2. Pluronic F127 and different type of surfactants, including nonionic, cationic, and anionic surfactants, were used as dual templates to investigate the influence on the morphology and nanostructure of the as-prepared carbon samples. TEM, SEM, N2 sorption, wide-angle and small-angle XRD analysis were employed to reveal the well-ordered hierarchically micro-mesoporous structure with 2D hexagonal symmetry by using compressed CO2. The prepared HPC samples with different pressures as the catalyst carriers have been functioned by chlorosulfonic acid for the fructose conversion into HMF. Chlorosulfonic acid concentration, catalyst dosage and reaction temperature have been optimized for fructose-to-HMF transformation with the obtained catalyst. The performances of as-made HPC–SO3H samples in HMF yield and reaction rate of fructose-to-HMF transformation have been investigated. The stability of the samples was also conducted in the dehydration of fructose to HMF for five cycles. The possible catalytic mechanism by using hierarchically porous carbon materials as catalyst support for fructose-to-HMF transformation was proposed.

Multi-direction impact forging (MDIF) was applied to the as-extruded ZK60 Mg alloy, and the microstructure, texture evolution and yield strength symmetry were investigated in the current study. The results showed that the average grain size of forged piece was greatly refined to 5.3 μm after 120 forging passes, which was ascribed to the segmenting effect of {10–12} twins and the subsequent multiple rounds of dynamic recrystallization (DRX). A great deal of {10–12} twins were activated at the beginning of MDIF process, which played an important role in grain refinement. With forging proceeding, continuous and discontinuous DRX were successively activated, resulting in the fully DRXed microstructure. Meanwhile, the forged piece exhibited a unique four-peak texture, and the initial //ED fiber texture component gradually evolved into multiple texture components composed of //FFD (first forging direction) and //FFD texture. The special strain path was the key to the formation of the unique four-peak texture. The {10–12} twinning and basal slip were two dominant factors to the evolution of texture during MDIF process. Grain strengthening and dislocation strengthening were two main strengthening mechanisms of the forged piece. Besides, the symmetry of yield strength was greatly improved by MDIF process.

Epoxy resin powder coating has been successfully applied on the corrosion protection of magnesium lithium alloys. However, poor wear resistance and microcracks formed during the solidification have limited it extensive application. There are limited approaches to exploit such anti-corrosion and mechanical properties of magnesium lithium alloys. Herein, the epoxy resin powder coating with polydopamine modified molybdenum disulfide (MoS2@PDA-EP powder coating with 0, 0.1, 0.2, 0.5, 1.0 wt.% loading) was well prepared by melt extrusion to investigate its anticorrosion performance and wear resistance. The results revealed that the addition of MoS2@PDA enhanced the adhesion strength between coatings and alloys, wear resistance and corrosion protection of the powder coatings. Among them, the optimum was obtained by 0.2 wt.% MoS2@PDA-EP powder coating which could be attributed to well dispersion and efficient adhesion with coating matrix. To conclude, MoS2@PDA-EP powder coating is meaningfully beneficial for the anticorrosive and wear performance improvement of magnesium lithium alloys.

ispartof: ADVANCED ENERGY MATERIALS status: Published online

Inspired by nature’s molecular machines, the scientific research on solid-state molecular rotors is of great interest yet remains largely unexplored. Herein, we report a unique example of a thermal...

Rational design of advanced structure for transition metal oxides (TMOs) is attractive for achieving high-performance supercapacitors. However, it is hampered by sluggish reaction kinetics, low mass loading, and volume change upon cycling. Herein, hierarchical NiCo2O4 architectures with 2D-nanosheets-shell and 3D-nanocages-core (2D/3D h-NCO) are directly assembled on nickel foam via a facile one-step way. The 2D nanosheets are in-situ generated from the self-evolution of initial NCO nanospheres. This 2D/3D hierarchical structures ensure fast ion/electron transport and maintain the structural integrity to buffer the volume expansion. The 2D/3D h-NCO electrode with an ultrahigh mass loading (30 mg cm−2) achieves a high areal capacity of 4.65 C cm−2 (equivalent to 1.29 mAh cm−2) at a current density of 4 mA cm−2, and retains 3.7 C cm−2 even at 50 mA cm−2. Furthermore, the assembled solid-state hybrid supercapacitor yields a high volumetric energy density of 4.25 mWh cm−3 at a power density of 39.3 mW cm−3, with a high capacity retention of 92.4% after 5000 cycles. Therefore, this work provides a new insight to constuct hierarchical electrodes for energy storage application.

Elemental doping confined in atomically-thin 2D semiconductors offers a compelling strategy for constructing high performance photocatalysts. Although impressive progress has been achieved based on co-thermolysis method, the choices of dopants as well as semiconductor hosts are still quite limited to yield the elaborate photocatalyst with atomic-layer-confined doping defects, owing to the difficulty in balancing the reaction kinetics of different precursors. This study shows that the cation exchange reaction, which is dictated by the Pearson's hard and soft acids and bases (HSAB) theory and allowed to proceed at mild temperatures, can be developed into a conceptually new protocol for engineering elemental doping confined in semiconductor atomic layers. To this aim, the two atomic layers of a new type of 2D photocatalyst PdSeO3 (PdSeO3 2Als, 1.1 nm) are created by liquid exfoliation and exploited as a proof-of-concept prototype. It is demonstrated that the Mn(II) dopants with controlled concentrations can be incorporated into PdSeO3 2ALs via topological Mn2+-for-Pd2+ cation exchange performed in water/isopropanol solution at 30 °C. The resulting Mn-doped PdSeO3 2ALs present enhanced capacity for driving photocatalytic oxidation reactions in comparison with their undoped counterparts. The findings here suggest that the new route mediated by post synthetic cation exchange promises to give access to manifold 2D confined-doping photocatalysts, with little perturbations on the thickness, morphology, and crystal structure of the atomically-thin semiconductor hosts.

The superlattice La-Y-Ni-based hydrogen storage alloys have high discharge capacity and are easy to prepare. However, there is still a gap in commercial applications because of the severe corrosion of the alloy in electrolyte and poor high-rate dischargeability (HRD). Therefore, (LaSmY)(NiMnAl)3.5 alloy was prepared by magnetic levitation induction melting, and then the alloy was coated with different contents (0.1 wt%–1.0 wt%) of nano-carbons by low-temperature sintering with sucrose as the carbon source in this work. The results show that the cyclic stability and HRD of the alloy first increase and then decrease with the increase of carbon contents. The kinetic results show that the electrocatalytic activity and conductivity of the alloy electrodes can be enhanced by carbon coating. The electrochemical properties of the alloy are the best when the carbon coating content is 0.3 wt%. Compared with the uncoated alloy, the maximum discharge capacity (Cmax) improves from 354.5 to 359.0 mAh/g, the capacity retention rate after 300 cycles (S300) enhances from 73.15% to 80.01%, and the HRD1200 of the alloy enhances from 74.39% to 74.39%.

Lithium–sulfur (Li–S) battery is labeled as a promising high-energy-density battery system, but some inherent drawbacks of sulfur cathode materials using relatively complicated techniques impair the practical applications. Herein, an integrated approach is proposed to fabricate the high-performance rGO/VS4/S cathode composites through a simple one-step solvothermal method, where nano sulfur and VS4 particles are uniformly distributed on the conductive rGO matrix. rGO and sulfiphilic VS4 provide electron transfer skeleton and physical/chemical anchor for soluble lithium polysulfides (LiPS). Meanwhile, VS4 could also act as an electrochemical mediator to efficiently enhance the utilization and reversible conversion of LiPS. Correspondingly, the rGO/VS4/S composites maintain a high reversible capacity of 969 mAh/g at 0.2 C after 100 cycles, with a capacity retention rate of 82.3%. The capacity fade rate could lower to 0.0374% per cycle at 1 C. Moreover, capacity still sustains 795 mAh g–1 after 100 cycles in the relatively high-sulfur-loading battery (6.5 mg/cm2). Thus, the suggested method in configuring the sulfur-based composites is demonstrated a simple and efficient strategy to construct the high-performance Li–S batteries.

Ceria-zirconia mixed oxides (CZMO) is widely used in many important catalysis fields. However, pure CZMO is known to have poor thermal stability. In this paper, a strategy was proposed to design high thermal stability Ce0.475Zr0.475M0.05O2 (M=La, Y, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Er, Lu, and, Yb) oxide surface by using first-principles molecular dynamics (FPMD) simulation and experiment method. Through the structure stability analysis at different temperatures, the surface energy γ as a function of Rion/Dave is identified as a quantitative structure descriptor for analyzing the doping effect of rare earth (RE) elements on the thermal stability of Ce0.475Zr0.475M0.05O2. By doping the suitable RE, the γ can be adjusted to the optimal range to enhance the thermal stability of Ce0.475Zr0.475M0.05O2. With this strategy, it can be predicted that the sequence of thermal stability improvement is Y > La > Gd > Nd > Pr > Pm > Sm > Eu > Tb > Er > Yb > Lu, which was further verified by our experiment results. After thermal treatment at 1100 °C for 10 h, the specific surface area (SSA) of aged Y-CZ and La-CZ samples can reach 21.34 m2/g and 19.51 m2/g, which is 63.02% and 49.04% higher than the CZMO sample without doping because the surface doping of Y and La is in favor of inhibiting the surface atoms thermal displacement. In a word, the strategy proposed in this work can be expected to provide a viable way for designing the highly efficient CZMO materials in extensive applications and promoting the usages of the high-abundance rare-earth elements Y and La.

Nano-TATB was developed in microchannels by physical method and chemical method, respectively. The effects of total flow rate, number of microreactor plates, solvent/non-solvent ratio and temperature on the particle size of TATB in the physical method were studied. Prepared TATB were characterized by Nano Sizer, Scanning Electron Microscopy, Specific surface aperture analyzer, X-ray diffraction, Fourier transform infrared spectroscopy and Differential Scanning Calorimetry. The results show that the TATB obtained by physical method and chemical method are spherical, with average particle size of 130.66 nm and 108.51 nm, respectively. Specific surface areas of TATB obtained by physical and chemical methods are 21.37 m2/g and 21.91 m2/g, respectively. Compared with the specific surface area of micro-TATB (0.0808 m2/g), the specific surface area of nano-TATB is significantly increased. DSC test results show that the smaller the particle size of TATB, the lower the thermal decomposition temperature. In addition, by simulating the mixing state of fluid in microchannels and combining with the classical nucleation theory, the mechanism of preparing nano-TATB by microchannels was proposed.

Both a conventional flow distributer and an improved one with a flow buffer were applied respectively during the high pressure die casting (HPDC) process, and samples of AZ91D magnesium alloy with different microstructure mainly consisting of α-Mg grains, β-phase and porosities were obtained. According to the grain orientation analysis, the predominant deformation behavior in α-Mg grains was dislocation slip, supplemented by deformation twinning. Dislocation slip was more difficult to occur in the samples with the improved flow distributer on account of the fact that the size of α-Mg grains in the microstructure was finer and more uniform. During the in situ tensile deformation test, cracks were observed to initiate from gas-shrinkage pore and island-shrinkage, and two main crack propagation mechanisms, porosity growth and coalescence were found accordingly. When the crack was in contact with the β-phase, it would pass through and fracture the network β-phase, whereas bypass the island β-phase by detaching it from the surrounding α-Mg grains. Mechanical property tests showed that the samples with relatively more homogeneous microstructure would perform higher mechanical properties, which was the combined effect of matrix α-Mg grains, β-phase, and porosities.

Silicon-based nanosheets (SNS) were synthesised via a mild (60 °C) and time-saving (8 h) modified topochemical method. Then, Cu3(BTC)2 and SNS@Cu3(BTC)2 were successfully synthesised by microwave irradiation, and their characteristics and hydrogen storage performance were analysed by multiple techniques. The accordion-like SNS exhibited void spaces, a unique low buckled structure, and ultrathin, almost transparent, loosely stacked layers with a high specific surface area (362 m2/g). After in-situ synthesis with Cu3(BTC)2, the SNS compound achieved a high specific surface area (1526 m2/g), outstanding hydrogen storage performance (5.6 wt%), and a desirable hydrogen diffusion coefficient (10−7). Thus, SNS doping improved the hydrogen storage performance of Cu3(BTC)2 by 64% through electron transfer reactions with Cu enabled by the unique composite nanostructure of SNS@Cu3(BTC)2. This study presents a promising method of synthesising SNS and porous composite materials for hydrogen storage.

It is recognized that the rotor with a shielding cylinder (SC) is one of the effective measures to restrain the rotor eddy current loss (RECL) for high-speed surface-mounted permanent magnet synchronous motors (PMSMs). At present, the RECL of PMSMs with multilayer composite rotor structure is mainly analyzed by the finite element method (FEM), which has obvious shortcomings in time-consumption and the mesh generation of the thin SC. In this paper, a multi-layer subdomain analytical model for calculating the RECL of high-speed PMSMs with both non-ferromagnetic retaining sleeve and SC is proposed by taking the effects of eddy current reaction, stator slotting and current harmonics into account. Moreover, the 3-D distribution coefficient of eddy current in the SC is derived by the equivalent impedance method and the effects of temperature on the conductivity of the SC and RECL are obtained through equivalent thermal network model. Based on the analytical model, the SC parameters are calculated to obtain the variation ranges when the RECL is minimum. Finally, the C-shape core experiment was built up to verify the correctness of the multilayer analytical model under different shielding layer conductivities and thicknesses.

In order to study the influence of the bolt joint mode on low-velocity projectiles penetrating the composite protective structure, two bolt joint models which connect the composite target to the fixed frame were designed, the ballistic test of the bolted composite protective structure with limited span was carried out, and the bearing and failure characteristics of the bolted region, as well as the energy dissipation of each part of the structure, were analyzed. The results show that in the condition of low-velocity impact, there are three failure modes for the bolted composite protective structure subjected to projectile penetration, including failure of the impact point of the composite target, failure of protective structure connecting components and failure of the holes in the bolted region of the composite target; the failure mode of bolt holes in the bolted region has a great influence on the protection performance, and the allowable value of the bearing capacity of the bolted region depends on the sum of the minimum failure load in the failure modes and the friction force; shear-out failure occurring in the bolt holes in the bolted region exerts the greatest effect on ballistic performance, which should be avoided; When simultaneous failure occurs in the bolted region and the free deformation region of the composite protective structure, the energy absorption per unit surface density of the composite protective structure reaches the maximum, which can give full play to its anti-penetration efficiency.

Bismuth sulfide (Bi2S3) is a promising anode material for high-performance potassium ion batteries due to its high theoretical capacity. However, the poor conductivity and substantial volume expansion hinder its practical application. We proposed an iodine-doped graphene encapsulated Bi2S3 nanorods composite (Bi2S3/IG) as an efficient anode for PIBs. The uniform-sized Bi2S3 nanorods evenly in-situ encapsulated in iodine-doped graphene framework, facilitating the electron transportation and structural stability. The potassium storage performance was evaluated in three electrolytes, with the best option of 5 mol/L KFSI in DME. The reversible capacity of representative Bi2S3/IG reached 453.5 mAh/g at 50 mA/g. Meanwhile, it could deliver an initial reversible capacity of 413.6 mAh/g at 100 mA/g, which maintained 256.9 mAh/g after 200 cycles. The proposed strategy contributes to improving potassium storage performance of metal sulfide anodes.

High entropy alloys (HEAs) with superb mechanical properties have been traditionally produced by solidification and subsequent heat treatment. In this paper, we demonstrate a new route via one-step process using sub-rapid cooling. Under proper cooling rates, the CrFeCoNiAl0.6 HEA could form ultrafine FCC+BCC dual-phase structure. By varying cooling rate, we can control the fraction of the BCC phase and refinement of FCC microstructures that have tunable mechanical properties in yield strength and hardness ranging from ∼580 to ∼1460 MPa and ∼260 to ∼550 Hv. We show that the structure-property-processing relation originates from the sideplate microstructures formed during fast cooling that have specific crystallographic orientation relationship between the FCC and BCC phases and chemical segregation. This work provides a new setting for better understanding of the solid-state phase transformation in HEAs under sub-rapid solidification conditions as well as a novel method for development of high-performance HEAs.

Polyvinyl alcohol (PVA)/laponite (LP) nanocomposite coatings were fabricated via a facile one-step coassembly process. The formed nanocoatings contain a high concentration of LP nanosheets, which can be well aligned along the substrate surface during the coassembly process. Due to the highly orientated structure, the flexible nanocoatings exhibit ultra-high transparency and superior mechanical properties, and can also act as excellent gas barriers. Such nanocoatings can be exceptional candidates for a variety of applications, such as food packaging.

Octane and p-xylene are common components in crude gasoline, so their separation process is very important in petroleum industry. The azeotrope and near azeotrope are often separated by extractive distillation in industry, which can realize the recovery and utilization of resources. In this work, the vapor-liquid equilibrium experiment was used to obtain the vapor-liquid equilibrium properties of the difficult separation system, and on this basis, the solvent extraction mechanism was studied. The mechanism of solvent separation plays a guiding role in selecting suitable solvents for industrial separation. The interaction energy, bond length and charge density distribution of p-xylene with solvent are calculated by quantum chemistry method. The quantum chemistry calculation results and experiment results showed that N-Formylmorpholine is the best solvent among the alternative solvents in the work. This work provides an effective and complete solvent screening process from phase equilibrium experiments to quantum chemical calculation. An extractive distillation simulation process with N-Formylmorpholine as solvent is designed to separate octane and p-xylene. In addition, the feasibility and effectiveness of the intensified vapor recompression assisted extraction distillation are also discussed. In the extractive distillation process, the vapor recompression-assisted extraction distillation process is globally optimal. Compared with basic process, the total annual cost can be reduced by 43.2 %. This study provides theoretical guidance for extractive distillation separation technology and solvent selection.

The selection and development of cathode of alkaline zinc batteries (AZBs) is still hindered and often leads to poor rate capability and short cycle life. Here, amorphous hollow nickel-cobalt-based sulfides nanocages with nanosheet arrays (AM-NCS) are designed and constructed with ZIF-67 as the self-template to exchange with Ni2+ and S2− by using a two-step ion exchange method. The synthesized AM-NCS possess the high specific capacity (160 mAh/g at 2 A/g), and the assembled battery has excellent rate performance (146 mAh/g reversible capacity at 5 A/g). The assembled device has excellent rate performance (155 mAh/g at 2 A/g) and long cycling stability (7000 cycles, 62.5% of initial capacity). The excellent electrochemical properties of the electrode materials are mainly attributed to the unique structure, in particular, polyhedron structure with hollow structure can improve the cyclic stability, and the amorphous structure can expose more reactive sites on the surfaces of nickel, cobalt and sulfur. This work provides a new strategy for the design and fabrication of high performance cathode materials for AZBs.

The disc-seal single screw pump (DSSP) used in the field of high viscosity oily sludge transport has a huge advantage. However, there is no research on the pressurization characteristics of the DSSP at present, which makes its application limited. In view of this, the pressurization process mathematical model of the DSSP was established based on the geometric model of the pump. By using this model, the pressurization characteristics of DSSP and the influence of working parameters on the pressurization process were studied combined with the principle of back-flow pressurization. Analysis results show that the instantaneous pressurization process could be realized mainly depending on the reflux pressurization from the outlet chamber to the pressurization chamber when the screw rotor rotating angle is located at -5° to +5°. The pressure in the pressurization chamber will increase with the increase of working parameters which include inlet pressure, outlet pressure, screw rotation velocity and dynamic viscosity of fluid medium in the area of flow-back pressurization. The screw rotation velocity and the viscosity of the conveying medium have significant effects on the peak pressure in the pressurization chamber, and the peak pressure in the pressurization chamber is proportional to the screw rotation velocity and the dynamic viscosity coefficient of the conveying medium. The proportional coefficient between the peak pressure and the screw rotation velocity is 6.29×104. The proportional coefficient between the peak pressure and the dynamic viscosity of the conveying medium is 6.28×106.

In this study, mesoporous TiO2 with various hydrolysis rates were prepared and combined with H2O2 for the photodegradation of unsymmetrical dimethylhydrazine (UDMH) under VUV irradiation. Results showed that the mesoporous TiO2 synthesized by the hydrolysis in water (MT100) exhibited a good mesoporous structure and the largest specific surface area (178.85 m2 g−1). Consequently, MT100 showed the best degradation efficiency, with the rate constant (k) for VUV/MT100 and VUV/MT100/H2O2 of 0.0185 and 0.2595 min−1, respectively, which was 1.4 and 4.0 times of that of P25. The addition of H2O2 significantly enhanced the degradation efficiency by photoactivation of H2O2 and the synergistic effect. The rate constant and the mineralization rate (after a 3-h treatment) increased by 13 and 3.8 times when 40 mM H2O2 was added into VUV/MT100. The weak alkaline condition (pH = 9) would facilitate the degradation of UDMH. The ⋅OH was the key oxidizing species in VUV/MT100/H2O2. Eight intermediates were detected during the degradation and the possible pathways of UDMH degradation in VUV/MT100/H2O2 process were proposed. VUV/MT100/H2O2 provides an efficient method to degrade UDMH.

Although organic redox molecules as electrode materials can achieve a high specific capacity through molecular design engineering, effective strategies to overcome their low cycling stability have not yet been developed. Herein, we establish a novel strategy that utilizes a strong dipole effect to suppress the high solubility of organic molecules and, thus, improve cycling stability. Two organic single crystals of squaraine derivative molecules with different substituents, 2,4-di(piperidin-1-yl)cyclobutane-1,3-dione (SAPD) and 2,4-di(pyrrolidin-1-yl)cyclobutane-1,3-dione (SAPL), were synthesized by facile routes. In particular, the SAPL cathode exhibited a discharge capacity of 371 mA h g–1 at 48 mA g–1 (0.1 C) and a nearly 78% capacity retention after 1000 cycles at 0.24 A g–1 (0.5 C). It also exhibited a capacity of 135 mA h g–1 even at 4.8 A g–1 (10 C) without hybridizing with graphene or carbon nanotubes. We studied the molecular interactions of SAPD and SAPL via detailed density functional theory calculations and revealed their lithium-ion storage mechanisms by using ex-situ technologies. Through comparing their intermolecular interactions, we found the stronger dipole effect can elevate cycling performance better. Hence, our design strategy can serve as a promising path for constructing high-performance lithium-organic batteries with long-term cycling stability.

Photoelectrochemical (PEC) water splitting over TiO2 photoanodes is a promising strategy for hydrogen production due to its eco-friendly, energy-saving, and low-cost nature. However, the intrinsic drawbacks of TiO2, i.e., the too wide band gap and rapid exciton recombination, significantly limit further enhancement of its performance. Herein, we report a TiO2 nanotube array (TNA), which is implanted by Cu ions and decorated by polymeric carbon nitride (PCN) nanosheets, as a photoanode for the high-efficiency PEC water splitting. In such designed material, Cu-ion implantation can effectively tailor the electronic structure of TiO2, thus narrowing the band gap and enhancing the electronic conductivity. Meanwhile, the PCN decoration induces TiO2/PCN heterojunctions, enhancing the visible light absorption and accelerating the exciton separation. Upon this synergistic effect, the modified TNA photoanode shows significantly improved PEC capability. Its photocurrent density, solar-to-hydrogen efficiency, and applied bias photon-to-current efficiency achieve 1.89 mA cm-2 at 1.23 VRHE (V vs reversible hydrogen electrode), 2.31%, and 1.20% at 0.46 VRHE, respectively. Importantly, this modified TNA supported on a meshlike Ti substrate can be readily integrated with a perovskite solar cell to realize unassisted PEC water splitting.

Graphitic carbon nitride (g-C3N4) is a metal-free photocatalyst with visible light response. However, the disadvantages limit its application in a wider range, such as its small specific surface areas, fewer active sites, narrow visible light absorption range and high photogenic carrier recombination. In this paper, NaOH was used as activator for alkaline activation of g-C3N4. The phase composition, micromorphology, surface chemical state and optical properties of g-C3N4 after activation were tested. The photocatalytic performance of g-C3N4 over organic dyes was also tested. The results showed that Na+ entered the interlayers of g-C3N4, expanding the spaces between layers. The specific surface area and pore volume of powder were increased. The active sites were increased. The band gap was decreased, and the photogenic carrier recombination was reduced. Alkaline activated g-C3N4 had better adsorption and degradation performance over rhodamine B and methyl orange than inactivated g-C3N4. Therefore, the alkaline activated g-C3N4 promotes its further application in the field of wastewater treatment. This work sheds light on the material modification through a simple method with the aim to efficiently use solar energy.

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 the oxygen redox ability shows great effects on the catalytic performances of ceria-zirconia based materials, many strategies have been utilized to improve the oxygen storage capacity. Here in this study, we report a simple and facile approach to prepare a SO42–-modified La, Y-doped ceria-zirconia material (SO/CZLY-f) with high oxygen storage capacity. Due to the additional redox process between SO42− and S2−, oxygen storage capacity of SO/CZLY-f (745.3 μmol O2/g) is about 1.6 times higher than that of La, Y-doped ceria-zirconia material without SO42– modification. Moreover, the catalytic activities and stability of the corresponding Pd-only three-way catalyst were measured. Compared to that of Pd@CZLY-f, the operation window of CO, full conversion temperature of HC and NO over Pd@SO/CZLY-f are obviously widened and lowered, respectively. After aging treatment at 1100 °C for 4 h, the superiority of aged Pd-loading composite is still maintained.

A facile and mild route to synthesize C-coated SiC nanosheets (SiC/C NSs) via wet-chemical etching in hydrofluoric acid (HF) at 60 °C for 48 h using carbon aluminum silicate (Al4SiC4) as raw materials is reported for the first time. HF molecule leads to the breaking of C-Al bonds in Al4SiC4, which eventually results in the formation of two-dimensional SiC nanosheets. A carbon layer with a thickness of approximately 1.5 nm is formed on the surface of SiC nanosheets due to the excess carbon. The prepared SiC/C NSs possess a smooth and rectangular sheet with a mean 150 nm in width, 500 nm in length and 10 nm in thickness, respectively. The crystallographic characterization indicates that 3C-SiC and 2H-SiC coexist and the parallel plane relationship of 3C/2H-SiC heterojunction is (111)3C-SiC//(001)2H-SiC. Due to the formed 3C-SiC/2H-SiC heterojunction and graphitic carbon, the fabricated electrode based on SiC/C NSs exhibits prolonged cycling stability and high specific areal capacitance as a promising supercapacitor candidate. It remains 91.2% retention even after 20000 cycles and 734 μF/cm2 at a scan rate of 10 mV/s.

The sluggish kinetics for water oxidation is recognized as one of the major problems for the unsatisfied photoelectrochemical (PEC) performance. Herein, we developed a feasible strategy based on in-situ selective surface cation exchange, for activating surface water oxidation reactivity toward boosted PEC water oxidation of BiVO4 photoanodes with fundamentally improved surface charge transfer. The as-constructed Co/BiVO4 photoanodes exhibit 2.6 times increase in photocurrent density with superior stability, in comparison to those of pristine counterpart. Moreover, the faradaic efficiency of as-fabricated photoanode can be up to ∼95% at 1.23 V (vs. RHE). The unique selective replacement of Bi by Co on the surface could modify the electronic structure of BiVO4 with reduced energy barrier of the deprotonation of OH* to O, thus favoring the overall excellent PEC performance of Co/BiVO4 photoanode.

Enhancing the water permeation while maintaining high salt rejection of existing reverse osmosis (RO) membranes remains a considerable challenge. Herein, we proposed to introduce polymer of intrinsic microporosity, PIM-1, into the selective layer of reverse osmosis membranes to break the trade-off effect between permeability and selectivity. A water-soluble a-LPIM-1 of low-molecular-weight and hydroxyl terminals was synthesized. These designed characteristics endowed it with high solubility and reactivity. Then it was mixed with m-phenylenediamine and together served as aqueous monomer to react with organic monomer of trimesoyl chloride via interfacial polymerization. The characterization results exhibited that more “nodule” rather than “leaf” structure formed on RO membrane surface, which indicated that the introduction of the high free-volume of a-LPIM-1 with three dimensional twisted and folded structure into the selective layer effectively caused the frustrated packing between polymer chains. In virtue of this effect, even with reduced surface roughness and unchanged layer thickness, the water permeability of prepared reverse osmosis membranes increased 2.1 times to 62.8 L∙m–2∙h–1 with acceptable NaCl rejection of 97.6%. This attempt developed a new strategy to break the trade-off effect faced by traditional polyamide reverse osmosis membranes.