Mn2+-doped CsPbCl3 perovskite nanocrystals (NCs) exhibit a significant Stokes shift and emit bright orange-red light, making them promising candidates for optoelectronic devices. However, these NCs are prone to surface defects during multiple purification steps, which hinder the transfer of energy from excitons to Mn2+ and reduce luminescence efficiency. Herein, we introduce a post-treatment method using a CaCl2 ethanol solution to passivate surface defects in Mn2+-doped CsPbCl3 NCs. This treatment enhances the energy transfer from excitons to Mn2+ and boosts luminescence performance, achieving a photoluminescence quantum yield of up to 96 % and maintaining stability through several washing cycles. In this process, Ca2+ ions, as a Lewis acid, replace oleic acid molecules on NC surfaces, leading to stronger binding. The Cl− from the CaCl2 solution fill vacancies on NC surfaces, effectively passivating surface defects. This reduces non-radiative recombination centers, increases energy transfer efficiency from 83 % to 87 %, and accelerates the radiative recombination rates of excitons and Mn2+. The post-treated NCs also retain their PL against continuous heat and ultraviolet irradiation. The passivation of surface defects on perovskite NCs achieved through this post-processing strategy enhances the energy transfer from excitons to doped ions, providing guidance for achieving efficient and stable doped perovskite NCs.

Structural defects in two-dimensional (2D) materials are ubiquitous and can influence their physical and chemical properties. The presence of structural defects in single atom thick 2D materials such as graphene is detrimental to the tribological properties and is well documented; however, their effects on various other 2D materials such as transition metal dichalcogenides (TMDs) remain largely unexplored. Here, we report the role of wrinkles’ orientation on the nanoscale tribological behavior of the chemical vapor deposited (CVD) tungsten disulfide (WS2) monolayers. Our molecular dynamics (MD) simulations reveal the underlying atomistic mechanism which indicates the presence of wrinkles exhibiting various orientations, and maximum damage occurred when the tip moved at a 45-degree angle to the wrinkle. This underscores the significant influence of wrinkles’ orientation on the wear behavior of WS2 monolayers.

It is an effective strategy that constructing composites with a multi-dimensional structure synergistically enhance their electromagnetic (EM) wave absorbing performance. Herein, a high-efficiency EM wave absorber of Mo2C/C nanoclusters uniformly encapsulated in rGO nanosheets (Mo2C/C-rGO) was prepared by a combination of the directing freeze-dry and subsequently carbothermal reaction method. Mo2C/C was in-situ induced from spherical phosphomolybdic acid/polypyrrole (PMo12/PPy) to result in a unique cluster-like microstructure. Abundant heterogeneous interfaces endowed the Mo2C/C-rGO composites with excellent EM wave absorption performance at a low filling ratio of 5 wt%. The minimum reflection loss (RL) value was −49.3 dB at 1.38 mm and the maximum effective absorption bandwidth (EAB, RL<-10 dB) was 5.12 GHz at 1.60 mm. The excellent performance was owing to the lamellar structure and abundant heterogeneous interfaces in Mo2C/C-rGO, lengthening the transmission path of the incident wave, as well as resulting in high conduction loss and interfacial polarization loss. This universal strategy would be extended to other absorbers with multi-interface structures for lightweight and broadband EM wave absorption.

Ti-Si-C coatings with different carbon contents were prepared on SS316L substrates by heterogeneous targets high-power impulse magnetron sputtering with a repetitive C and TiSi deposition. Various tests were employed to analyze the microstructure, anti-corrosion properties in a simulated proton exchange membrane fuel cells (PEMFC) environment and interfacial conductivity of the coatings. Results indicated that the Ti-Si-C coating possessed a typical nanocomposite structure of TiC nanocrystals embedded in amorphous carbon matrix. With the increase of the carbon content, the grain size of TiC nanocrystals was reduced gradually. Electrochemical measurements revealed that a proper decrease of TiC grain size led to an enhanced corrosion resistance of the as-deposited coating. The smallest interfacial contact resistance and corrosion rate of the Ti-Si-C coating in the simulated PEMFC solution reached 5.07 mΩ cm2 and 5.93E-07 A/cm2, respectively. This improvement could be attributed to the formation of a dense and continuous passivation layer composed of Ti2O3 and SiO2 on the top surface of the coating.

In this comprehensive study, we explore the electrocatalytic behavior of novel two-dimensional (2D) monolayers composed of anti-MXene borides (TMB) towards the nitrate reduction reaction (NO3RR) using density functional theory (DFT). The analysis reveals that these TMB monolayers emerge as promising candidates for electrochemical NO3RR, characterized by their exceptional stability, advantageous selectivity, and effective activation properties. Our study reveals that anti-MXene TMB monolayers, including MnB, RhB, CoB, IrB, OsB, and FeB, exhibit significant electrocatalytic potential for nitrate reduction, each with notable catalytic efficiencies demonstrated by their limiting potentials of −0.25 V, −0.29 V, −0.34 V, −0.36 V, −0.66 V, and −0.70 V, respectively. MnB shows a distinct preference for the NO3--to-N2 conversion pathway, whereas CoB, FeB, and OsB effectively facilitate both the NO3--to-NH3 and NO3--to-N2 pathways. Intriguingly, IrB and RhB primarily favor the NO3--to-NH3 pathway, highlighting their potential in ammonia synthesis applications. These variations in pathway preference not only underscore the diverse catalytic capabilities of these monolayers but also open new avenues for tailored catalytic applications and deepen our understanding of the mechanisms of nitrate reduction.

Studying the spreading of droplets on heterogeneous surfaces is significant for understanding various phenomena, from petroleum engineering to material science, due to its implications for wetting behavior, surface interactions, and functional coating applications. In this work, we investigated the spread of droplets on heterogeneous surfaces using molecular dynamics simulations. The results showed that the contact line approach can predict the equilibrium contact angle of droplet well. We found significant differences in the spreading of droplets on heterogeneous surfaces with different lyophilic pattern sizes, and then we explained the difference in droplet spreading on different heterogeneous surfaces by the proportion of lyophobic and lyophilic regions covered by contact lines. This study emphasizes the importance of contact lines in droplet spreading dynamics and enhances our understanding of the relationship between contact lines and droplet spreading.

Aiming at the poor intrinsic conductivity and huge volume expansion of transition metal sulfides, carbon-coated cuprous sulfide hollow nanoboxes (Cu2S@C) with core–shell structure were designed via co-precipitation, facial carbon coating and in-situ sulfurization methods, and exhibited significantly improved electrochemical properties applied as sodium ion battery anode. The uniformly coated carbon shell can enhance the electrolyte infiltration, promote charge transfer efficiency, accelerate electrochemical conversion redox kinetics. The conversion reaction reversibility of restricted Cu2S cores show a significant improvement benefitting from accelebrating ion diffusion and spatial limitation. During the sulfidation, robust chemically and electronically bonded connections such as C-S moieties formed between the two phases, creating interconnected channels that facilliate rapid charge transfer kinetics and optimize structural durability. Moreover, the hollow core–shell structure can provide a buffer space for tolerating volume expansion and preventing agglomeration arising from the repeating Na+ insertion/desertion process, which can availably enhance cyclic stability. Thanks to the synergistic effect between strong interfacial coupling and hollow core–shell structure, the Cu2S@C composite can deliver an improved Na+ storage performance. At the high current density of 1.0 A/g, the Cu2S@C anode could exhibit a specific capacity of 100.08 mAh/g, which is significant ameliorative than Cu2S counterpart (only 11.6 mAh/g).

Laser-induced graphene (LIG), created through CO2 laser irradiation of polyimide film (PI) substrates, has emerged as a versatile and promising material in numerous fields. However, despite its potential, a comprehensive exploration of LIG’s surface structure and reactivity remains absent in the literature, which is crucial for advancing its applications in electrochemical and electroanalytical fields. In this study, we developed and examined the interfacial structure and electronic behavior of an Ag-La(OH)3@Dy2O3 hybrid composite-modified LIG system as a model. We employed scanning electrochemical microscopy (SECM) to investigate these properties, extending our analysis to the simultaneous detection of organic pollutants, such as bisphenol A (BPA) and tartrazine (TRZ), in real samples. Compared to previous LIG production techniques, the LIG-modified electrode demonstrated a high electron transfer rate at the interface. The tailored LIG substrate showed excellent electrochemical activity towards electrochemical oxidation and simultaneous electroanalytical applications for BPA and TRZ with low detection limits (BPA: 9.2 nM, TRZ: 0.96 nM) in neutral physiological conditions. As a proof of concept, an extension to the real-time application of simultaneous monitoring of BPA and TRZ in various food samples was successfully demonstrated.

The exploration of efficient and noble-metal-free photocatalysts for photocatalytic H2 production is still a hot topic. Herein, a novel NiCo2O4/CdIn2S4 S-scheme heterojunction composites were successfully synthesized. Morphology characterization manifests that CdIn2S4 nanoparticles are tightly bound to the rod NiCo2O4 to form S-scheme heterojunction. Besides, X-ray photoelectron spectroscopy (XPS) results verify the existence of co-existing cobalt and nickel ions with multivalent state, which could provide H2 evolution active site and form redox centers. The S-scheme heterojunction and redox centers prompt the transfer of photogenerated e− from CdIn2S4 to NiCo2O4 for improving carrier separation efficiency, which is confirmed by a series of electrochemical experiments and photoluminescence (PL). The specific surface area and transmission electron microscope (TEM) results show that NiCo2O4 possesses a high specific surface area and porous structure, which could provide more active sites and facilitate H2O adsorption for further reduction reaction. The optimal NiCo2O4/CdIn2S4 composites possess maximum H2 evolution rate of 624 μmol·g−1·h−1, which is about 3.2 times than CdIn2S4-1 %Pt (198 μmol·g−1·h−1). After three cycles, the activity of NiCo2O4/CdIn2S4 shows no significant weaken. Moreover, the possible H2 evolution mechanism of NiCo2O4/CdIn2S4 S-scheme heterojunction composites is discussed. This research offers an idea for bimetallic oxide (NiCo2O4 etc.) modified sulfide to improve photocatalytic hydrogen production.

Although electrode materials with flower-like structures have showing promising achievement for battery energy storage for stable structure and rich specific surface area, there are still some challenges in precisely controlling their microstructure. Inspired by the hydrolysis and self-assembly of MgO into petal-like magnesium hydroxide crystals under alkaline critical micelle conditions, we have proposed to synthesize a unique phenolic resin with a 3D flower-like structure as a carbon precursor. After a series of treatments, the optimal sample consists of nanosheets (thickness ≈ 27 nm) extending in all directions from the core, with a porous structure, significant specific surface area of 2028 m2/g and pore volume of 1.79 m3/g. Electrochemical experiments confirmed that the sample exhibits satisfactory electrochemical performance as the electrode of supercapacitor. It shows an amazing unique capacitance of 320.1F/g, and the charge–discharge capacity retention rate exceeds 94.6 % after 5000 cycles. Moreover, a high energy density of 9.44Wh/kg at 126 W/kg is shown for the symmetrical supercapacitors. We believe that the 3D flower-like morphology formed by the unique lamellar structure can provide more active sites, promote ion transports and increase the stability of structure. These findings suggest a new strategy to control the morphology of phenolic resin-based carbon materials.