We explore the effect of ionic surfactants on the photoluminescence (PL) of single emissive CdSe nano‐tetrapods. In the presence of the cationic surfactant cetyltrimethylammonium bromide (CTAB), effective quenching of PL is observed for tetrapods. X‐ray photoelectron spectroscopy (XPS) reveals the adsorption of negatively charged Br − ions onto the nanocrystal surface, which leads to efficient PL quenching. In particular, the longer‐lived trap‐state emission is suppressed due to the accumulation of surfactant counterions at the tetrapod surface. In contrast, sodium dodecyl sulfate (SDS), an anionic surfactant, shows negligible interaction with the negatively charged Se 2− ‐terminated surface, resulting in sustained PL intensity. These results demonstrate that the immediate surface environment and counterion adsorption play a critical role in modulating the photoluminescence properties of CdSe nano‐tetrapods.
A low‐cost and sensitive chemiresistive gas sensor based on a p‐type CuO and n‐type g‐C 3 N 4 (copper oxide and graphitic carbon nitride) nanocomposite is described. A simple hydrothermal process was used to create the CuO@g‐C 3 N 4 heterostructure, which was then applied as a sensing layer on interdigitated electrodes. CuO nanoparticles successfully formed a porous p–n heterojunction on g‐C 3 N 4 sheets, as demonstrated by structural, morphological, and compositional investigations. At room temperature (RT), both reducing (H 2 ) and oxidizing (CO 2 ) gases were tested by the newly fabricated sensor with outstanding performance. With response times of 10 s for H 2 and 8 s for CO 2 , as well as recovery times of 10 and 7 s, respectively, the device showed quick response and recovery characteristics. High sensitivity was also demonstrated by the sensor's low limit of detection (LOD), which was 44.98 sccm for H 2 and 13.23 sccm for CO 2 . Increased surface area, the creation of an efficient p–n heterojunction, and the synergistic effect of CuO and g‐C 3 N 4 are all responsible for the improved sensing behavior.
In this study, we report the synthesis of nitrogen‐doped Mn 3 O 4 /amorphous carbon (N–Mn 3 O 4 /AC) composites via a one‐step solvothermal method, employing linoleic acid (LA) and N,N‐dimethylacetamide (DMAc) as dual‐functional agents for carbon templating and nitrogen doping, respectively. The presence of high‐valent manganese‐oxo (Mn─O) moieties (terminal Mn 4+ ═O), graphitic domains, and redox‐active nitrogen functional groups in the carbon matrix and onto the Mn 3 O 4 surface effectively enhanced the electrical conductivity and redox activity of the resulting composite. Electrochemical performance revealed that the N‐doped Mn 3 O 4 /AC delivered a high specific capacitance of 293.3 F g −1 at a current density of 0.5 A g −1 in 1 M Na 2 SO 4 electrolyte, while maintaining an excellent rate capability of 79% at 5 A g −1 . Remarkably, this N‐doped Mn 3 O 4 /AC electrode achieved 4.4 times higher capacitance than undoped Mn 3 O 4 . Moreover, the composite retained over 80% of its initial capacitance after 2000 charge–discharge cycles at 0.5 A g −1 , underscoring its excellent long‐term stability. Electrochemical impedance spectroscopy (EIS) revealed low charge transfer resistance and favorable ion diffusion kinetics. These findings establish N‐doped Mn 3 O 4 /AC composites as a promising and scalable electrode material for high‐performance supercapacitors and hybrid energy storage systems.
The development of room‐temperature ammonia (NH 3 ) sensors with high sensitivity, selectivity, and stability remains a significant challenge for environmental monitoring and healthcare applications. Herein, an interfacial‐engineered P3HT–SnO 2 quantum dot (QD) composite was developed for high‐performance room‐temperature NH 3 sensing. The composite was fabricated through a facile wet‐chemical method, where SnO 2 QDs were uniformly integrated with the p‐type P3HT matrix to construct abundant heterointerfaces. The optimized P3HT–SnO 2 QD sensor with a mass ratio of 1:1 exhibited significantly enhanced NH 3 sensing performance, achieving a high response of 188.31% toward 50 ppm NH 3 at room temperature, together with excellent reproducibility, long‐term stability, and anti‐interference capability. The enhanced sensing behavior is attributed to the formation of p–n heterojunctions between P3HT and SnO 2 QDs, along with the quantum confinement effect of SnO 2 QDs to generate abundant surface‐active sites, which induce interfacial charge redistribution, facilitate carrier transport, and promote NH 3 adsorption and surface reactions. Furthermore, density functional theory (DFT) calculations reveal the preferential adsorption of NH 3 molecules on the P3HT–SnO 2 interface, providing theoretical insights into the improved sensing selectivity. This work demonstrates an effective interfacial engineering strategy for constructing high‐performance organic–inorganic hybrid NH 3 sensors operating at room temperature.
The field of thermal conductivity is one of the important applications of polymers. However, polymer material generally possesses low thermal conductivity due to its internal characteristic, which cannot meet the heat dissipation requirement of device. Therefore, the preparation of polymer material with high thermal conductivity has broad application prospect and important significance. To achieve this goal, a new‐type composite film was fabricated via electrospinning and hot pressing treatment. Utilizing the self‐polymerization of dopamine under alkaline condition, polydopamine (PDA) was deposited on the surface of boron nitride (BN). The obtained BN@PDA acted as filler for polyvinyl alcohol (PVA). In addition, polyvinylidene fluoride (PVDF) was introduced into PVA through coaxial spinning. The results indicated that the thermal conductive filler was uniformly distributed and well adhered on the fiber. Moreover, thanks to the intermolecular force between PVA and PVDF, the acquired composite film had good thermal stability with the decomposition temperature over 300 °C. On the other hand, the got composite film exhibited good thermal conductivity at low filling ratio. It could quickly transfer the heat generated during the operation of the LED light, which could reduce the operating temperature of the equipment in actual use, demonstrating its good heat dissipation capability.
This study focused on synthesis of functionalized graphene oxide‐carboxymethylcellulose (GO‐CMC) aerogel to remove methylene blue (MB) dye from water. FTIR, XPS, Raman spectroscopy, XRD, and SEM confirmed incorporation of carboxymethylcellulose (CMC) within graphene oxide (GO) framework. Dye selection experiments proved the aerogel’s preferential uptake of MB when compared to other dyes like methyl orange (MO) and Rhodamine B (Rh B). Time studies achieved a high removal efficiency of ~98% within 100 min, with an experimentally observed adsorption capacity of 261.02 mg/g under kinetic conditions. Kinetic modeling indicated that chemisorption was predominant, with the Elovich and pseudo‐second‐order models providing the best fit. Isothermal analysis demonstrated that the Langmuir model fits well among the tested models, predicting a theoretical monolayer adsorption capacity ( Q max ) of 90.74 mg/g. These findings confirm that the adsorption process is due to electrostatic, π–π interactions, hydrogen bonding, and physical trapping within the aerogel’s porous structure.
A highly innovative and streamlined electrochemical deposition route is introduced for the fabrication of MoS 2 thin films on FTO substrates, offering a breakthrough alternative to conventional high‐temperature or vacuum‐based synthesis methods. This approach employs plasma‐assisted exfoliated MoS 2 nanosheets and an electric‐field‐directed self‐assembly mechanism to produce vertically oriented, few‐layer 2H‐MoS 2 architectures in a rapid, low‐energy, and reduced reagent consumption. The method requires no specialized instrumentation yet yields films with remarkable crystallinity, well‐defined lattice features, and near‐stoichiometric Mo 4+ /S 2− composition, demonstrating an unprecedented balance between process simplicity and material quality. The resulting electrodes exhibit substantially enhanced photoelectrochemical performance, including a reduction in charge‐transfer resistance from 3242 to 1720 Ω under illumination and a stable photocurrent of ~6 μA, outperforming typical solution‐processed MoS 2 systems. This work establishes a facile electrochemical route that can simultaneously achieve structural stability, catalytic accessibility, and strong light‐responsive behavior. The strategy presented here opens a promising and scalable pathway for next‐generation MoS 2 ‐based photoelectrodes and catalytically active interfaces.
This study focuses on fabricating SiO 2 ‐incorporated PVA/PVP/SF fiber composite, which holds significant potential for BTE applications due to its integrated bioactivity, biocompatibility, and porosity. SiO 2 was synthesized through the sol–gel route, and the fibrous scaffold via electrospinning. X‐ray diffraction (XRD), Fourier transform ‐ infrared (FT‐IR) and field‐emission scanning electron microscopy (FE‐SEM) confirmed the structural and morphological characteristics of the scaffolds. The porosity reached 99% within 48 h, ensuring good cell attachment and proliferation. Scaffolds showed an adequate hydrophilicity and a tensile strength of 8.75 MPa, with 80.2% elongation at break. The antibacterial activity of SiO 2 against Escherichia coli (13 ± 0.51 mm) and Staphylococcus aureus (11.8 ± 0.75 mm) was significantly improved in fibrous composites with the highest inhibition zones of 30.3 ± 1.03 and 28.0 ± 0.96 mm, respectively. Good hemocompatibility, cytocompatibility, bioactivity, and calcium mineralization ability, along with an increased ALP activity after 14 days, supported the osteogenic potential of the scaffold in BTE.
This review explores the rapidly emerging, promising domain of Janus nanofiber‐based triboelectric nanogenerators (TENGs). We focus on Janus nanofibers with anisotropic, dual‐faced chemical or physical properties, due to their exceptional potential for engineering high‐performance wearable electronics and self‐powered sensors. The review systematically examines how the inherent structural and functional asymmetry of Janus nanofibers, such as differential conductivity, tailored surface energy on opposing sides, and gradient porosity, enables superior control over triboelectric charge generation, retention, and collection. The discussion is anchored by summarizing state‐of‐the‐art device performances, where Janus nanofiber TENGs have demonstrated exceptional outputs (e.g., >140 V, power densities in the mW range) and remarkable robustness over thousands of cycles. Furthermore, this article critically evaluates the application horizon unlocked by Janus designs. Their multifunctional nature enables dual‐mode operation as sensitive, self‐powered sensors that detect physiological signals (e.g., pulse, swallowing) and biomechanical motions (e.g., joint bending with angle‐specific electrical responses) with high signal distinguishability. This focus is motivated by a significant gap in the literature; despite their transformative advantages, Janus nanofiber TENGs have not been the subject of a dedicated, in‐depth review, leaving their unique design principles and synergistic benefits underexplored.
Multivalent supramolecular assemblies based on cyclodextrins and biomacromolecules have attracted considerable attention from researchers owing to their wide application in fields such as cell imaging, drug delivery, and food preservation. Herein, ternary supramolecular nanoassemblies are constructed by per‐[6‐deoxy‐mercaptopropionic acid]‐ γ ‐cyclodextrin (SgCD), chitosan (CS), and curcumin (Cur, a natural compound from a herb), displaying not only pH‐responsive reversible assembly and disassembly but also the controlled release of drug. Initially, two types of nanoparticles (SgCD–CS) with average sizes of 188 and 342 nm are facilely fabricated using anionic SgCD and cationic CS with different deacetylation degrees, driven by the multivalent electrostatic interactions between them. These SgCD–CS nanoparticles exhibit excellent stability and pH‐responsiveness. Subsequently, taking advantage of the strong host–guest interaction between SgCD and Cur, the SgCD–CS nanoparticles efficiently load Cur, and the ternary supramolecular assemblies show superior antioxidant activity compared to free Cur, as confirmed by DPPH radical scavenging assays. Notably, Cur is stably encapsulated within the SgCD–CS nanoparticles under acidic conditions but released under alkaline conditions, highlighting the system’s potential for targeted delivery and stimuli‐responsive release. The pH sensitivity and loading/release capability for larger‐sized bioactive molecules render the SgCD–CS nanoparticles promising candidates for applications in the fields of functional foods and pharmaceuticals.
Photothermally active nanomaterials have attracted significant interest due to their efficient light‐to‐heat conversion, enabling a wide range of applications. Among them, nanostructures of binary copper sulfides (Cu 2– x S, where 0 ≤ x ≤ 1) are particularly promising for near‐infrared (NIR)‐driven photothermal applications because of their strong NIR absorption arising from plasmonic behavior. Within the Cu 2– x S family, CuS (covellite) exhibits the most pronounced plasmonic response, making it an attractive platform for NIR photothermal conversion. In this work, we demonstrate a simple synthesis strategy for CuS nanostructures based on the hydrothermal decomposition of bis(diethyldithiocarbamato)copper(II), a readily accessible single‐source precursor. The resulting materials are hierarchical structures composed of nanoplate subunits, whose thickness and stacking behavior are influenced by polyvinylpyrrolidone. These hierarchical CuS nanostructures exhibit intense NIR extinction features and excellent photothermal activity and stability, which were successfully exploited for NIR‐driven interfacial water evaporation.
Harvesting waste heat near room temperature via thermoelectrics is technologically important, enabling energy recovery from sources such as the human body to power portable devices. Silver selenide (Ag 2 Se) is a promising candidate due to its high conversion efficiency in this range, yet reported performance varies widely with composition, microstructure, and processing. This study systematically investigates the influence of annealing conditions (temperature and atmosphere) on the microstructure and thermoelectric properties of Ag 2 Se. Results show that the annealing atmosphere (Ar or N 2 ) has negligible effect, while annealing temperature critically governs stoichiometry, grain size, and carrier concentration. Annealing at 200 °C produces Ag vacancies (Ag/Se < 2.0), which act as electron acceptors and reduce carrier concentration to near the optimal level. This enhances the Seebeck coefficient and power factor, yielding the highest figure of merit ( ZT ). In contrast, annealing at 300 °C (above the melting point of Se) induces partial Se evaporation, leading to Ag interstitials (Ag/Se > 2.0) that act as electron donors. This increases carrier concentration beyond the optimal range, reducing the power factor and ZT . Overall, precise control of annealing temperature is essential for microstructural engineering in Ag 2 Se, providing a practical pathway to optimize transport properties and enhance thermoelectric performance.
This work examines the effect of defect engineering on the photocatalytic desulfurization of methyl thioglycolate and its downstream C─C coupling with styrene using modified TiO 2 nanoparticles. Fully oxidized nanoparticles show high desulfurization yields (97.7%) but poor C─C coupling selectivity (14.5%) due to a lack of surface defects. Controlled reduction in NH 3 atmosphere at mild temperatures (300–400 °C) introduces surface defects (Ti 3+ centers and oxygen vacancies) without modifying the bulk lattice. These surface defects stabilize intermediate carbon radicals, dramatically increasing C─C coupling yields to over 84%. Higher reduction temperatures (≥500 °C) severely diminish photocatalytic activity by depletion of surface Ti 4+ sites and eventual transformation into crystalline TiN. The study highlights the critical role of surface chemistry tuning in balancing photocatalytic activity and selectivity.
Efficient catalysts for water oxidation are important in the development of artificial photosynthesis. Although noble metal catalysts show excellent catalytic performance and stability, their scarce availability and high cost have restricted their further practical application. Accordingly, Co‐based molecular catalysts are currently the focus of very intense research as highly appealing earth‐abundant alternatives. This review highlights a systematic consideration of their design principles, with emphasis on two major factors: nuclearity (mono‐, di‐, and multinuclear architectures) manipulation, and ligand engineering. The nuclearity dictates the catalytic framework, the degree of metal–metal cooperativity, and the catalytic mechanism. The ligands are intended to function as stabilizing high‐valent intermediates, promoting electron/proton transfer and thereby enhancing efficiency through fine electronic, steric, and redox‐active tuning. By connecting these features, this review establishes a consistent structure–activity relationship and offers perspectives on the design of robust and high‐performance Co‐based molecular catalysts for sustainable energy conversion.
The structure of hole‐transport material (HTM) determines the efficiency of perovskite solar cells (PSCs). In this work, we investigate how the nature of the solvent used for the HTM deposition defines its morphology and crystallinity in thin films and the performance of PSCs. A benzodithiophene‐based material (BDT) capable of forming highly crystalline thin films was deposited from various solvents and their mixtures. Thin BDT thin films were characterized using X‐ray diffraction, optical microscopy and atomic force microscopy. BDT films deposited from heptane formed long narrow crystals and possessed large surface roughness, which significantly reduced the devices efficiency. The amorphous BDT films obtained from chlorobenzene enabled the highest efficiencies up to 16.3% in undoped PSCs.
In this study, three silver surfaces with morphologies from 0D to 3D were realized by wet‐chemical reduction of mono‐, bi‐ and triatomic silver salts on silicon surfaces. First, we found that the choice of the starting silver salt can influence the formation of silver nanostructures ranging from nanoparticles to dendrites. Second, we found that the surface‐enhanced Raman scattering (SERS) signal is highly dependent on the selected starting silver salt. Using adenine as a test analyte, our studies showed that surfaces with dendritic structures obtained using silver sulfate and phosphate exhibit much higher SERS sensitivity, and that surfaces obtained using silver sulfate have significantly higher chemical stability with respect to oxidation when stored in ambient conditions for 8 weeks compared to standard silver surfaces obtained from silver nitrate. The implementation of synchrotron‐based XPS studies, which allowed the variation of kinetic energy and surface analysis depth profiling, showed that silver nitrate formed surfaces begin significantly to oxidize after 2 weeks, and initially exhibit a heterogeneous surface structure that has a “sandwich”‐like structure, in which oxidized silver phases are present in the metallic silver matrix, compared to pure silver surfaces terminated with sulfate or phosphate groups obtained from silver sulfate or phosphate.
Development of Earth‐abundant bifunctional electrocatalysts like NiCo 2 O 4 for water electrolysis is a potential key enabler of hydrogen economy. Nevertheless, the influence of synthesis parameters on the morphology, and thus, the catalytic activity of NiCo 2 O 4 remained insufficiently investigated. Herein, porous NiCo 2 O 4 spinel nanowires synthesized via simple hydrothermal method coupled with thermal annealing in air were employed as bifunctional electrocatalyst for overall water electrolysis in alkaline condition. Specifically, the effect of hydrothermal temperature on the microstructure of NiCo 2 O 4 and the eventual catalytic activity is emphasized. Employing ECSA‐corrected evaluation of electrochemical performance and standardized characterization tools, an optimum hydrothermal temperature of 120 °C was determined. The corresponding NiCo 2 O 4 exhibited respectable intrinsic activity on graphite substrate without additional co‐catalyst. Catalytic current density of 30 and 10 mA cm − 2 was achieved with overpotentials of 343 and 360 mV for hydrogen and oxygen evolution reactions, respectively. For overall water electrolysis, a cell voltage of 2.2–2.0 V was enough to sustain 10 mA cm −2 for 35 h, reaching near 100% Faradaic efficiency. The evolution of the catalyst layers was also monitored using SEM, EDX, XPS, and Raman spectroscopy. Insights into the formation and evolution of the catalyst layer and of the working mechanism of the resultant electrolyzer were provided.
Copper (Cu)‐ and silver (Ag)‐based composite coatings on fomite surfaces have been shown to be effective in reducing the spread of pathogens such as viruses and antibiotic‐resistant bacteria. Herein, a facile, scalable, one‐step spray‐drying protocol using ascorbic acid as a green reducing agent and water as the solvent was developed to prepare Cu and Ag‐doped Cu microparticles for subsequent composite antimicrobial coating preparation. Silver doping affected the overall particle size and the hierarchical structure within a particle, as evidenced by dynamic light scattering, small‐angle X‐ray scattering, and electron microscopy. Crystallinity was confirmed by X‐ray and electron diffraction, while the distribution of silver and copper within the spray‐synthesized microparticles was assessed through EDX elemental mapping and X‐ray photoelectron spectroscopy. Composite coatings were prepared by embedding the microparticles in polymethyl methacrylate (PMMA) matrix via in situ free radical polymerization using benzoyl peroxide and applied on glass and stainless‐steel substrates. The antimicrobial efficacy of these composite coatings was determined by observing complete inhibition of Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus bacterial strains. The practicality of the approach was further demonstrated by coating a fomite surface, a stainless‐steel door knob, with the microparticle‐embedded PMMA composite and observing complete inhibition of bacterial growth.
Flow-electrode capacitive deionization (FCDI) enables continuous desalination, yet its performance is fundamentally governed by charge storage and transport within the flow electrodes. Despite extensive use of conductive additives, the role of their intrinsic physicochemical properties in determining desalination behavior remains poorly understood. Here, we systematically reveal how the particle size and surface potential of conductive additives regulate inter-particle interactions and slurry viscosity, thereby controlling flow dynamics and desalination efficiency. Combined experimental measurements and numerical simulations show that, compared with Ketjen Black, carbon nanotubes possess larger particle sizes and share the same surface charge polarity as activated carbon, leading to substantially reduced slurry viscosity and improved flow stability. Coupled with their higher intrinsic capacitance, these features enable flow electrodes to deliver enhanced desalination performance. This work provides guidelines for the rational selection and optimization of conductive additives, advancing the design of high-performance FCDI systems for desalination.
This study investigates the topotactic conversion of cobalt hydroxide (CHY) to cobalt oxide (COX) and its influence on electrochemical performance. CHY was synthesized by a simple precipitation method and thermally decomposed in a muffle furnace at 300°C for 2 h to obtain Co 3 O 4 . The CHY and COX were thoroughly characterized by thermogravimetric analysis (TGA), X‐ray diffraction (XRD), Raman spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. Field emission scanning electron microscopy (FESEM) images revealed that the nanorod morphology of the hydroxide was retained after calcination. Characterizations confirmed successful topotactic transformation of α ‐Co(OH) 2 to Co 3 O 4 without any secondary phase. Electrochemical measurements demonstrated a significant difference in charge‐storage behavior: CHY exhibited a specific capacitance of 570 F g −1 at 1 A g −1 , while COX showed 188 F g −1 under identical conditions. Cyclic voltammetry performed at scan rates from 2.5 to 100 mV s −1 and galvanostatic charge–discharge (GCD) at 0.5–8 A g −1 further supported the enhanced pseudocapacitive behavior of CHY. Electrochemical impedance spectroscopy (EIS) revealed a much lower charge‐transfer resistance for CHY compared to COX, indicating faster electron transport. The results confirm that the topotactic transformation preserves morphology and improves structural stability, although it reduces ion diffusion and available active surface area, resulting in lower capacitance in the oxide phase.
