The design and fabrication of ultrafine nanostructures in two-dimensional (2D) van der Waals materials are crucial for the functionalization of electronic devices. Here, we report the utilization of far-field femtosecond laser patterning to fabricate super-resolution nano-groove array (NGA) structures in 2D multilayer NbOI₂ in ambient air, achieving groove widths as low as ~14.5 nm (~λ/73). The NGA structures maintain a well-defined single-crystal NbOI₂ with amorphous Nb₂O₅ edges as narrow as 3.2 nm. The formation mechanism of NGA structure is confirmed to be associated with the coupled field of surface plasmon polariton periodic field and nano-groove-induced local near-field induced by femtosecond laser irradiation. Furthermore, the NGA-NbOI₂ gas sensor exhibits NO₂ sensing performance, with a rapid response time (5.1 s), which is attributed to the existence of abundant NbOI₂-Nb₂O₅ heterojunctions. This approach will propel the further development of nano-lithography techniques for functional device applications of 2D materials.

Aqueous zinc-ion batteries provide a most promising alternative to the existing lithium-ion batteries due to their high theoretical capacity, intrinsic safety, and low cost. However, commercializing aqueous zinc-ion batteries suffer from dendritic growth and side reactions on the surface of metallic zinc, resulting in poor reversibility. To overcome this critical challenge, here, we report a one-step ultrafast laser processing method for fabricating three-dimensional micro-/nanostructures on zinc anodes to optimize zinc nucleation and deposition processes. It is demonstrated that the three-dimensional micro-/nanostructure with increased specific surface area significantly reduces nucleation overpotential, as well as preferentially absorbs zinc ions to prevent dendritic protuberances and corrosion. As a result, the presence of three-dimensional micro-/nanostructures on the zinc metal delivers stable zinc plating/stripping beyond 2500 h (2 mA cm^-2/1 mAh cm^-2) in symmetric cells, a high Coulombic efficiency (99.71%) in half cells, and moreover an improved capacity retention (71.8%) is also observed in full cells. Equally intriguingly, the pouch cell with three-dimensional micro-/nanostructures can operate across various bending states without severely compromising performance. This work provides an effective strategy to construct ultrafine and high-precision three-dimensional micro-/nanostructures achieving high-performance zinc metal anodes and is expected to be of immediate benefit to other metal-based electrodes.

Paint removal is an important part of ship and marine engineering ship processing. Aluminum alloy is extremely vital in the field of shipbuilding, due to its high strength and strong corrosion resistance ability. Therefore, the cleaning quality of aluminum alloy is a key factor in the service life of the ship. In this paper, the research about continuous wave (CW) laser cleaning technique is employed to clean the paint on the substrate of aluminum alloy. The track width and depth of laser ablated craters are measured to study the removal rates. The analysis of CW laser cleaning is performed to explain the removal process that is theoretically based on the cleaning model, temperature, and the thermal stress profiles. The parametric and morphological studies indicate that the cleaned surface of aluminum alloy could be achieved at proper parameters. The performance of the laser cleaned surface at an intensity of 11.9 W/cm² has better corrosion resistance and surface roughness. Therefore, the experimental results were considered to provide more completed and further understandings of interaction mechanism between the laser and paint on the aluminum alloy substrate, which could make some contributions to the development of laser manufacturing.

Black phosphorus (BP), owing to its distinguished properties, has become one of the most competitive candidates for photodetectors. However, there has been little attention paid on photo-response performance of multilayer BP nanoflakes with large layer thickness. In fact, multilayer BP nanoflakes with large layer thickness have greater potential from the fabrication viewpoint as well as due to the physical properties than single or few layer ones. In this report, the thickness-dependence of the intrinsic property of BP photodetectors in the dark was initially investigated. Then the photo-response performance (including responsivity, photo-gain, photo-switching time, noise equivalent power, and specific detectivity) of BP photodetectors with relative thicker thickness was explored under a near-infrared laser beam (λ_IR = 830 nm). Our experimental results reveal the impact of BP’s thickness on the current intensity of the channel and show degenerated p-type BP is beneficial for larger current intensity. More importantly, the photo-response of our thicker BP photodetectors exhibited a larger responsivity up to 2.42 A/W than the few-layer ones and a fast response photo-switching speed (response time is ~2.5 ms) comparable to thinner BP nanoflakes was obtained, indicating BP nanoflakes with larger layer thickness are also promising for application for ultra-fast and ultra-high near-infrared photodetectors.

SiC/SiC ceramic matrix composites (CMCs) are widely applied in the aerospace and nuclear industries due to their excellent material nature (strength, hardness, and irradiation tolerance) at high-temperature loads. However, high-quality machining cannot be easily realized because of the anisotropic material structure and its properties. In this study, a laser water jet (LWJ) was adopted for CMCs machining. Firstly, the finite element model (FEM) was established describing a representative three-dimensional microstructure including weft yarn, warp yarn, SiC base, and the pyrolytic carbon (PyC) fiber coating. The temperature distribution, as well as its evolution rule on substrate surface under LWJ machining, was analyzed. Moreover, a single-dot ablation test was carried out to verify the accuracy of the numerical simulation model. Secondly, the variation in maximum temperatures under different laser pulse energy was obtained by means of FEM. Nonetheless, a non-negligible deviation emerged in the ablation depth of the numerical calculation and experimental results. Although the simulation results were obviously superior to the experimental results, their proportions of different machining parameters reached an agreement. This phenomenon can be explained by the processing characteristics of LWJ. Finally, single-row and multi-row scribing experiments for CMCs with 3 mm thickness were developed to clarify the processing capacity of LWJ. The experimental results indicated that single-tow scribing has a limiting value at a groove depth of 2461 μm, while complete cutting off can only be realized by multi-row scribing of LWJ. In addition, the cross-section of CMCs treated by LWJ presented a surface morphology without a recast layer, pulling out of SiC fibers, and delamination. The theoretical and experimental results can offer primary technical support for the high-quality machining of CMCs.