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Composite sandwich structures are widely used in the aerospace field due to their advantages of high strength, lightweight, and fatigue resistance. However, these structures are prone to damage with very-low-energy impacts. In order to improve the impact resistance of aircraft skin structure, a low-velocity impact resistance of sandwich structure specimens was tested by means of drop hammer impact, and the impact damage area was scanned by ultrasonic C-scan, and obtains the impact damage of specimens with different impact energies and different ply sequences. Combined with the Hashin failure criterion, the finite element equivalent model of composite sandwich structure under low-velocity impact was established. The errors between the simulation results and the C-scan results of the test piece were less than 10%, in which the experimental measurements and numerical predictions were in close agreement. Finally, the finite element equivalent model was applied to optimize the application of model sandwich, which was used for fuselage skin of a certain electric aircraft. The total thickness of the laminate structure remains unchanged before and after optimization, but the impact resistance was significantly enhanced. The ±45° lay-up was beneficial for the structure to absorb the impact energy.

Zinc oxide (ZnO) has been widely acknowledged as a highly effective photocatalyst for the degradation of organic pollutants. In this study, we presented silver nanoparticles (AgNPs) embedded ZnO foam photocatalyst (Ag−ZnO) on glass substrates by the chemical bath in‐situ co‐deposition method. Our findings demonstrat that at low Ag‐loading content, metallic Ag0 NPs are embedded within the ZnO foam, while at high Ag‐loading content, they accumulates increasingly from inside to the surface of the foam. With the increase of AgNPs loading from 0.1 mM to 1.5 mM, the absorption of Ag−ZnO foams in the visible light region gradually enhances. The photocatalytic degradation efficiency of rhodamine B (RhB) is the highest in Ag−ZnO foams when the Ag loading concentration reaches 0.8 mM, suggesting an optimal content of Ag for enhanced performance. This trend is attributed to the photo‐induced charge transfer behavior of Ag−ZnO samples. The AgNPs embedded inside the ZnO foam enhance the separation of photo‐induced charges and prevent their recombination. As a result, Ag−ZnO(0.8 mM) foam with more photo‐induced holes participate in the photocatalytic reaction, leading to a remarkably high photocatalytic activity. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Inverted perovskite solar cells (PerSCs) are a highly promising candidate in the photovoltaic field due to their low‐temperature fabrication process, negligible hysteresis, and easy integration with Si‐based solar cells. A cathode interlayer (CIL) is necessary in the development of inverted devices to reduce the trap density and energy barrier between the electron transport layer (ETL) and the electrode. However, most CILs are highly thickness‐sensitive due to low conductivity and poor film‐forming. In this study, we report on a self‐doping perylene imide‐based ionene polymer (PNPDIN) used as CIL material to modify electrode in inverted PerSCs. PNPDIN exhibits high conductivity and a good solubility in polar solvent, which results in an improved power conversion efficiency (PCE) from 10.05% (device without a CIL) to 16.97%. When the blend of PNPDIN and Bphen was used as a mixed CIL, the PCE of PerSCs can be further increased to 21.28% owing to the excellent morphology and matched energy level. More importantly, the PCE of the device is highly tolerant to the thickness of the mixed CIL, which benefited from the high conductivity of PNPDIN. This development is expected to provide an excellent mixed CIL material for roll‐to‐roll processing efficient and stable inverted PerSCs. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting has attracted strong interest as sustainable technology by converting solar energy into hydrogen. The semiconductor photoelectrodes play an important role to increase the solar‐to‐hydrogen conversion efficiency. Bismuth vanadate (BiVO4) is an excellent candidate as a photoanode material for PEC water oxidation because of its visible light absorption, suitable band edge location, high stability and low cost. However, BiVO4 alone may undergo short carrier diffusion length, rapid recombination of photo‐induced charge carriers and photocorrosion. The heterojunction strategy established by combining two or more materials has provided an outstanding technique to address these issues. This Review focuses on recent important works with respect to BiVO4 heterojunction photoanodes for PEC water oxidation reactions, including interface junction and surface functional junction formation. Additionally, challenges faced and prospects for future research on BiVO4 heterojunction photoanodes in the field of solar‐to‐hydrogen conversion are proposed. [ABSTRACT FROM AUTHOR]

To supply wear-resistant coatings on AISI 310 austenitic stainless steel for harsh industry applications, Ni3Al intermetallic compound coatings were prepared by high-velocity oxygen fuel (HVOF) spraying. Ni3Al coatings were deposited under different oxygen/fuel ratios of 4.45, 4.89 and 5.34. The phase structure, microstructure, mechanical and tribological properties of the coatings at 25 °C were investigated firstly. As a result, the HVOF oxygen/fuel ratio of 4.89 was chosen to get the best physical properties of an average porosity 1.0 vol.%, thickness 290 μm, hardness 527 ± 16 HV, friction coefficient 0.75 and wear rate 1.74 × 10− 5 mm3/(N·m). Then tribological tests across a wide temperature range from 25 to 800 °C were carried out on the optimized coating: the coating presented the highest anti-friction and wear resistance at 600 °C, a continuous and dense oxide layer comprised of NiO, Ni2O3, Al2O3 and NiAl2O4 was formed and acted as a solid lubricant, and contributed a relatively low friction coefficient of 0.57 and wear rate of 8.91 × 10− 5 mm3/(N·m). The wear mechanisms were mainly tribo-oxidation wear and slight abrasive wear. [ABSTRACT FROM AUTHOR]

It is still a challenge to prepare 2D ultrathin ZnO in a simple method, especially for the in‐situ growth of 2D ultrathin ZnO on different substrates. Herein the ZnO foam with high specific surface area is successfully assembled in situ from graphene‐like ultrathin nanosheet on various substrates, including rigid fluoride doped tin oxide, Ni foam, and flexible indium tin oxide, carbon cloth, etc. The thickness of graphene‐like nanosheet is just ≈1.5 nm. The results reveal that the specific surface area of ZnO nanosheets is 90.7 m2 g−1. The high specific surface area of the hydrophilic ZnO foam and its in‐situ growth characteristic make it promising water channel in solar‐driven interfacial water evaporation system. By using a flexible carbon cloth/ZnO foam (C‐ZnO) Janus absorber, a high rate of water evaporation (2.4 kg m−2 h−1), which is 4.6 times higher than that of natural evaporation is demonstrated. This work provides a new method in the design of ZnO ultrathin nanosheets, what's more, the facile growth of the ZnO foam on various substrates make it possible for the application in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Inverted perovskite solar cells (PerSCs) are a highly promising candidate in the photovoltaic field due to their low‐temperature fabrication process, negligible hysteresis, and easy integration with Si‐based solar cells. A cathode interlayer (CIL) is necessary in the development of inverted devices to reduce the trap density and energy barrier between the electron transport layer (ETL) and the electrode. However, most CILs are highly thickness‐sensitive due to low conductivity and poor film‐forming. In this study, we report on a self‐doping perylene imide‐based ionene polymer (PNPDIN) used as CIL material to modify electrode in inverted PerSCs. PNPDIN exhibits high conductivity and a good solubility in polar solvent, which results in an improved power conversion efficiency (PCE) from 10.05% (device without a CIL) to 16.97%. When the blend of PNPDIN and Bphen was used as a mixed CIL, the PCE of PerSCs can be further increased to 21.28% owing to the excellent morphology and matched energy level. More importantly, the PCE of the device is highly tolerant to the thickness of the mixed CIL, which benefited from the high conductivity of PNPDIN. This development is expected to provide an excellent mixed CIL material for roll‐to‐roll processing efficient and stable inverted PerSCs. [ABSTRACT FROM AUTHOR]

This study focuses on incorporating liquid molecules, different from the bulk solution, into the immobilized enzyme carrier to regulate the distribution effect and diffusion‐limiting impact of the carrier's microenvironment for substrates, which generally is difficult to achieve due to the instability of the materials with liquid inclusions. A freestanding liquid‐holding particle carrier, with bi‐component hydrophobic ionic liquid gel microspheres with poly (glycidyl methacrylate) as the network and 1‐butyl‐3‐methylimidazolium hexafluorophosphate as the dispersing medium, is proposed, which is stable in air aqueous solution, and can extract proteins and organic small molecules into its interior due to the mobility of its dispersing medium. Horseradish peroxidase is covalently immobilized into the microspheres, forming a liquid compartment enzyme microreactor. The microreactor exhibits superior stability, enzymatic activity, and catalytic performance for Basic Orange II degradation compared to free enzyme and liquid‐free immobilized enzymes. This is attributed to the biocompatibility of the ionic liquid, its role in substrate enrichment in its interior, and its rapid mass transfer capability. This contribution shows the effectiveness of regulating the carrier's microenvironment with liquid molecules, offering fresh perspectives and strategies for enzyme technology. [ABSTRACT FROM AUTHOR]