Search

CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (NCs) have shown great potential in numerous applications including wide color gamut display and lighting. Despite the wonderful luminescence properties, the inherent instability of these NCs hinders their use in practical situations. Herein, we report a facile aqueous-based, ligand-free method to synthesize highly stable CsPbX3 NCs using ZIF-62, a metal–organic framework, as an encapsulation matrix which effectively isolates CsPbX3 from the surrounding. We discovered that the slightly alkaline nature of ZIF-62 facilitates the reaction between water and PbBr2 to form PbBr-(OH), which not only passivates the surface defects of the CsPbBr3 NCs but also prevents the perovskite from decomposing or oxidizing at high temperature. Sintering of ZIF-62 can therefore be performed in air at ∼300 °C to completely seal the perovskite within the insulating matrix, resulting in CsPbBr3/ZIF-62 composites exhibiting high stability against polar solvents, heat, light, and ambient humidity. Notably, the composite can maintain its bright luminescence without noticeable degradation in water for more than 2 months. The narrow-band emission and stability of these composites led to the demonstration of white light-emitting diodes with excellent color stability. Without the need for organic solvents during NC synthesis and noble gas ambient during sintering, the strategy proposed here can potentially facilitate the cost-effective, large-scale synthesis of highly stable perovskites which show great promise in commercial applications. [ABSTRACT FROM AUTHOR]

Superhydrophobic metallic surfaces with mechanical stability as well as self-cleaning and anticorrosion functions are highly desirable because of their promising applications in various aspects. Large apparent water contact angles (≥150°) on metal surfaces are usually realized by high surface roughness and low surface energy. However, rough nanoscale features and low-energy coatings are prone to wear, causing degradation of the local wetting property during service. Herein, we develop a low-cost and scalable fabrication methodology to prepare composite superhydrophobic surfaces (water contact angle ∼154.7± 2.3° and sliding angle ∼1.2 ± 0.2°) by integrating a micropatterned amorphous alloy frame with functionalized nanoparticles. Amorphous interconnected microwalls provide augmented resistance against abrasion, whereas spray-coated nanomaterials residing within the frame impart water repellency. Metallic surfaces can withstand abrasion against sandpaper for 40 m under a local pressure of 120 kPa, before losing their perfect superhydrophobic performances. The composite surfaces also maintain its water repellency after mechanical bending, knife scratching, water impact jetting, ultraviolet (UV) irradiation, and acid immersion. We envisage that the design strategies here provide a practical route to manufacture water-repellent surfaces with metallic glass in harsh nautical applications. [ABSTRACT FROM AUTHOR]