Nanomaterials

Polyglycolic acid (PGA) nanoparticles show promise in biomedical applications due to their exceptional biocompatibility and biodegradability. These nanoparticles can be readily modified, facilitating targeted drug delivery and promoting specific interactions with diseased tissues or cells, including imaging agents and theranostic approaches. Their potential to advance precision medicine and personalized treatments is evident. However, conventional methods such as emulsification solvent evaporation via batch synthesis or tubular reactors via flow chemistry have limitations in terms of nanoparticle properties, productivity, and scalability. To overcome these limitations, this study focuses on the design and development of a 3D-printed vortex tube reactor for the continuous synthesis of PGA nanoparticles using flow chemistry. Computer-aided design (CAD) and the design of experiments (DoE) optimize the reactor design, and computational fluid dynamics simulations (CFD) evaluate the mixing index (MI) and Reynolds (Re) expression. The optimized reactor design was fabricated using fused deposition modeling (FDM) with polypropylene (PP) as the polymer. Dispersion experiments validate the optimization process and investigate the impact of input flow parameters. PGA nanoparticles were synthesized and characterized for size and polydispersity index (PDI). The results demonstrate the feasibility of using a 3D-printed vortex tube reactor for the continuous synthesis of PGA nanoparticles through flow chemistry and highlight the importance of reactor design in nanoparticle production. The CFD results of the optimized reactor design showed homogeneous mixing across a wide range of flow rates with increasing Reynolds expression. The residence time distribution (RTD) results confirmed that increasing the flow rate in the 3D-printed vortex tube reactor system reduced the dispersion variance in the tracer. Both experiments demonstrated improved mixing efficiency and productivity compared to traditional tubular reactors. The study also revealed that the total flow rate had a significant impact on the size and polydispersity index of the formulated PGA nanoparticle, with the optimal total flow rate at 104.46 mL/min, leading to smaller nanoparticles and a lower polydispersity index. Additionally, increasing the aqueous-to-organic volumetric ratio had a significant effect on the reduced particle size of the PGA nanoparticles. Overall, this study provides insights into the use of 3D-printed vortex tube reactors for the continuous synthesis of PGA nanoparticles and underscores the importance of reactor design and flow parameters in PGA nanoparticle formulation. Full article

Among semiconductor metal oxides, that are an important class of sensing materials, titanium dioxide (TiO₂) thin films are widely employed as sensors because of their high chemical and mechanical stability in harsh environments, non-toxicity, eco-compatibility, and photocatalytic properties. TiO₂-based chemical oxygen demand (COD) sensors exploit the photocatalytic properties of TiO₂ in inducing the oxidation of organic compounds to CO₂. In this work, we discuss nanostructured TiO₂ thin films grown via low-pressure metal organic chemical vapor deposition (MOCVD) on metallic AISI 316 mesh. To increase the surface sensing area, different inorganic acid-based chemical etching protocols have been developed, determining the optimal experimental conditions for adequate substrate roughness. Both chemically etched pristine meshes and the MOCVD-coated ones have been studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) microanalysis, and X-ray photoelectron spectroscopy (XPS). We demonstrate that etching by HCl/H₂SO₄ at 55 °C provides the most suitable surface morphology. To investigate the behavior of the developed high surface area TiO₂ thin films as COD sensors, photocatalytic degradation of functional model pollutants based on ISO 10678:2010 has been tested, showing for the best performing acid-etched mesh coated with polycrystalline TiO₂ an increase of 60% in activity, and degrading 66 µmol of MB per square meter per hour. Full article

Zirconium-based metallic glass films are promising materials for nanoelectronic and biomedical applications, but their mechanical behavior under different conditions is not well understood. This study investigates the effects of radio frequency (RF) power and test temperature on the nanostructure, morphology, and creep behavior of Zr₅₅Cu₃₀Al₁₀Ni₅ metallic glass films prepared by RF magnetron sputtering. The films were characterized by X-ray diffraction and microscopy, and their mechanical properties were measured by a bulge test system. The results show that the films were amorphous and exhibited a transition from noncolumnar to columnar morphology as the RF power increased from 75 W to 125 W. The columnar morphology reduced the creep resistance, Young’s modulus, residual stress, and hardness of the films. The creep behavior of the films was also influenced by the test temperature, with higher temperature leading to higher creep strain and lower creep stress. The findings of this study provide insights into the optimization of the sputtering parameters and the design of zirconium-based metallic glass films for various applications. Full article

The requirement of simple, efficient and accurate detection of tetracycline (TC) in water environments poses new challenges for sensing platform development. Here, we report a simple method for TC sensing via fluorescence detection based on metal–organic coordination polymers (MOCPs, (4-Hap)₄(Mo₈O₂₆)) coated with nitrogen-doped carbon dots (NCDs). These NCDs@(4-Hap)₄(Mo₈O₂₆) composites showed excellent luminescence features of NCDs with stable bright-blue emission under UV light. The results of the sensing experiment showed that the fluorescence of NCDs@(4-Hap)₄(Mo₈O₂₆) can be quenched by TC (166 μM) with 94.1% quenching efficiency via the inner filter effect (IFE) in a short time (10 s), with a detection limit (LOD) of 33.9 nM in a linear range of 8–107 μM. More significantly, NCDs@(4-Hap)₄(Mo₈O₂₆) showed a high selectivity for TC sensing in the presence of anions and metal cations commonly found in water environments and can be reused in at least six cycles after washing with alcohol. The potential practicality of NCDs@(4-Hap)₄(Mo₈O₂₆) was verified by sensing TC in real water samples with the standard addition method, and satisfactory recoveries from 91.95% to 104.72% were obtained. Full article

The exceptional property of plasmonic materials to localize light into sub-wavelength regimes has significant importance in various applications, especially in photovoltaics. In this study, we report the localized surface plasmon-enhanced perovskite solar cell (PSC) performance of plasmonic gold nanoparticles (AuNPs) embedded into a titanium oxide (TiO₂) microdot array (MDA), which was deposited using the inkjet printing technique. The X-ray (XRD) analysis of MAPI (methyl ammonium lead iodide) perovskite films deposited on glass substrates with and without MDA revealed no destructive effect of MDA on the perovskite structure. Moreover, a 12% increase in the crystallite size of perovskite with MDA was registered. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) techniques revealed the morphology of the TiO₂_MDA and TiO₂-AuNPs_MDA. The finite-difference time-domain (FDTD) simulation was employed to evaluate the absorption cross-sections and local field enhancement of AuNPs in the TiO₂ and TiO₂/MAPI surrounding media. Reflectance UV-Vis spectra of the samples comprising glass/TiO₂ ETL/TiO₂_MDA (ETL—an electron transport layer) with and without AuNPs in TiO₂_MDA were studied, and the band gap (E_g) values of MAPI have been calculated using the Kubelka–Munk equation. The MDA introduction did not influence the band gap value, which remained at ~1.6 eV for all the samples. The photovoltaic performance of the fabricated PSC with and without MDA and the corresponding key parameters of the solar cells have also been studied and discussed in detail. The findings indicated a significant power conversion efficiency improvement of over 47% in the PSCs with the introduction of the TiO₂-AuNPs_MDA on the ETL/MAPI interface compared to the reference device. Our study demonstrates the significant enhancement achieved in halide PSC by utilizing AuNPs within a TiO₂_MDA. This approach holds great promise for advancing the efficiency and performance of photovoltaic devices. Full article

Carbon nanotubes (CNT) (single-walled CNT, multiwalled CNT, non-covalently functionalized and covalently functionalized CNT, and/or CNT tailored with chemical or biological recognition elements) are by far the most popular nanomaterials thanks to their high electrical and thermal conductivities and mechanical strength, specific optical and sorption properties, low cost, and easy preparation, among other interesting characteristics [...] Full article

In this work, a dual interfacial passivation layer (IPL) consisting of TaON/GeON is implemented in GaAs metal-oxide-semiconductor (MOS) capacitors with ZrTaON as a high-k layer to obtain superior interfacial and electrical properties. As compared to the samples with only GeON IPL or no IPL, the sample with the dual IPL of TaON/GeON exhibits the best performance: low interface-state density (1.31 × 10¹² cm⁻² eV⁻¹), small gate leakage current density (1.62 × 10⁻⁵ A cm⁻² at V_fb + 1 V) and large equivalent dielectric constant (18.0). These exceptional results can be attributed to the effective blocking action of the TaON/GeON dual IPL. It efficiently prevents the out-diffusion of Ga/As atoms and the in-diffusion of oxygen, thereby safeguarding the gate stack against degradation. Additionally, the insertion of the thin TaON layer successfully hinders the interdiffusion of Zr/Ge atoms, thus averting any reaction between Zr and Ge. Consequently, the occurrence of defects in the gate stack and at/near the GaAs surface is significantly reduced. Full article

The interaction between metal particles and the oxide support, the so-called metal–support interaction, plays a critical role in the performance of heterogenous catalysts. Probing the dynamic evolution of these interactions under reactive gas atmospheres is crucial to comprehending the structure–performance relationship and eventually designing new catalysts with enhanced properties. Cobalt supported on TiO₂ (Co/TiO₂) is an industrially relevant catalyst applied in Fischer−Tropsch synthesis. Although it is widely acknowledged that Co/TiO₂ is restructured during the reaction process, little is known about the impact of the specific gas phase environment at the material’s surface. The combination of soft and hard X-ray photoemission spectroscopies are used to investigate in situ Co particles supported on pure and NaBH₄-modified TiO₂ under H₂, O₂, and CO₂:H₂ gas atmospheres. The combination of soft and hard X-ray photoemission methods, which allows for simultaneous probing of the chemical composition of surface and subsurface layers, is one of the study’s unique features. It is shown that under H₂, cobalt particles are encapsulated below a stoichiometric TiO₂ layer. This arrangement is preserved under CO₂ hydrogenation conditions (i.e., CO₂:H₂), but changes rapidly upon exposure to O₂. The pretreatment of the TiO₂ support with NaBH₄ affects the surface mobility and prevents TiO₂ spillover onto Co particles. Full article

Cadmium telluride (CdTe) is known as an important semiconductor material with favorable physical properties. However, as a soft-brittle material, the fabrication of high-quality surfaces on CdTe is quite challenging. To improve the fundamental understanding of the nanoscale deformation mechanisms of CdTe, in this paper, MD simulation was performed to explore the nano-grinding process of CdTe with consideration of the effects of grain size and grinding depth. The simulation results indicate that during nano-grinding, the dominant grinding mechanism could switch from elastic deformation to ploughing, and then cutting as the grinding depth increases. It was observed that the critical relative grain sharpness (RGS) for the transition from ploughing to cutting is greatly influenced by the grain size. Furthermore, as the grinding depth increases, the dominant subsurface damage mechanism could switch from surface friction into slip motion along the <110> directions. Meanwhile, as the grain size increases, less friction-induced damage is generated in the subsurface workpiece, and more dislocations are formed near the machined groove. Moreover, regardless of the grain size, it was observed that the generation of dislocation is more apparent as the dominant grinding mechanism becomes ploughing and cutting. Full article

Direct ascorbic acid fuel cells (DAAFCs) employ biocompatible ascorbic acid (AA) as fuel, allowing convenient storage, transportation, and fueling as well as avoiding fuel crossover. The AA oxidation reaction (AAOR) largely governs the performance of DAAFCs. However, AAOR electrocatalysts currently have low activity, and state-of-the-art ones are limited to carbon black. Herein, we report the synthesis of an unprecedented AAOR electrocatalyst comprising 3.9 ± 1.1 nm CeO₂ nanoparticles evenly distributed on carbon black simply by the wet chemical precipitation of Ce(OH)₃ and a subsequent heat treatment. The resultant CeO₂/C shows a remarkable AAOR activity with a peak current density of 13.1 mA cm⁻², which is 1.7 times of that of carbon black (7.67 mA cm⁻²). According to X-ray photoelectron spectroscopy (XPS), the surface Ce³⁺ of CeO₂ appears to contribute to the AAOR activity. Furthermore, our density functional theory (DFT) calculation reveals that that the proton of the hydroxyl group of AA can easily migrate to the bridging O sites of CeO₂, resulting in a faster AAOR with respect to the pristine carbon, -COOH, and -C=O sites of carbon. After an i-t test, CeO₂/C loses 17.8% of its initial current density, which is much superior to that of carbon black. CeO₂ can capture the electrons generated by the AAOR to protect the -COOH and -C=O sites from being reduced. Finally, DAAFCs fabricated with CeO₂/C exhibit a remarkable power density of 41.3 mW cm⁻², which is the highest among proton-exchange-membrane-based DAAFCs in the literature. Full article

Plasmonic nanostructures as narrowband perfect absorbers have garnered significant attention due to their potential applications in biosensing and environment detection. This study emphasizes the investigation of arrayed split ring nanostructures within the configuration of metal-insulator-metal (MIM) multilayers, resulting in a maximum light absorption of 99.94% in the near-infrared (NIR) spectral range. The exceptional absorption efficiency of the device is attributed to the strong resonance of electric and magnetic fields arising from the Fabry–Pérot cavity resonance. The resonant peak can be flexibly tuned by engineering the dielectric layer thickness, the period, and the geometric parameter of split rings. Remarkably, the device exhibits promising capabilities in sensing, demonstrating a sensitivity of 326 nm/RIU in visible wavelengths and 504 nm/RIU in NIR wavelengths when exposed to bio-analytes with varying refractive indices. This designed nanostructure can serve as a promising candidate for biosensors or environmental detection. Full article

In this study, anodic aluminum oxide membranes (AAOMs) and Au-coated AAOMs (AAOM/Au) with pore diameters of 55 nm and inter-pore spacing of 100 nm are used to develop ZnO/AAOM and ZnO/ZnAl₂O₄/Au nanoarrays of different morphologies. The effects of the electrodeposition current, time, barrier layer, and Au coating on the morphology of the resultant nanostructures were investigated using field emission scanning electron microscopy. Energy dispersive X-ray and X-ray diffraction were used to analyze the structural parameters and elemental composition of the ZnO/ZnAl₂O₄/Au nanoarray, and the Kirkendall effect was confirmed. The developed ZnO/ZnAl₂O₄/Au electrode was applied to remove organic dyes from aqueous solutions, including methylene blue (MB) and methyl orange (MO). Using a 3 cm² ZnO/ZnAl₂O₄/Au sample, the 100% dye removal for 20 ppm MB and MO dyes at pH 7 and 25 °C was achieved after approximately 50 and 180 min, respectively. According to the kinetics analysis, the pseudo-second-order model controls the dye adsorption onto the sample surface. AAOM/Au and ZnO/ZnAl₂O₄/Au nanoarrays are also used as pH sensor electrodes. The sensing capability of AAOM/Au showed Nernstian behavior with a sensitivity of 65.1 mV/pH (R² = 0.99) in a wide pH range of 2–9 and a detection limit of pH 12.6, whereas the ZnO/ZnAl₂O₄/Au electrode showed a slope of 40.1 ± 1.6 mV/pH (R² = 0.996) in a pH range of 2–6. The electrode’s behavior was more consistent with non-Nernstian behavior over the whole pH range under investigation. The sensitivity equation was given by V(mV) = 482.6 + 372.6 e^{−0.2095 pH} at 25 °C with R² = 1.0, which could be explained in terms of changes in the surface charge during protonation and deprotonation. Full article

Graphene, fullerenes, diamond, carbon nanotubes, and carbon dots are just a few of the carbon-based nanomaterials that have gained enormous popularity in a variety of scientific disciplines and industrial uses. As a two-dimensional material in the creation of therapeutic delivery systems for many illnesses, nanosized graphene oxide (NGO) is now garnering a large amount of attention among these materials. In addition to other benefits, NGO functions as a drug nanocarrier with remarkable biocompatibility, high pharmaceutical loading capacity, controlled drug release capability, biological imaging efficiency, multifunctional nanoplatform properties, and the power to increase the therapeutic efficacy of loaded agents. Thus, NGO is a perfect nanoplatform for the development of drug delivery systems (DDSs) to both detect and treat a variety of ailments. This review article’s main focus is on investigating surface functionality, drug-loading methods, and drug release patterns designed particularly for smart delivery systems. The paper also examines the relevance of using NGOs to build DDSs and considers prospective uses in the treatment of diseases including cancer, infection by bacteria, and bone regeneration medicine. These factors cover the use of naturally occurring medicinal substances produced from plant-based sources. Full article

This study used scanning electron microscopy via 3D dissection coupled with synchrotron radiation with microfocal beams of both small-angle X-ray scattering and wide-angle X-ray diffraction to analyze the periodic crystal aggregates of unusual poly(p-dioxanone) (PPDO) dendritic cactus-arm-like ring bands upon crystallization with a diluent poly(vinyl alcohol) (PVA) that is capable of hydrogen bonding interactions with PPDO. Three-dimensional microscopy interior dissection clearly expounds that the banded periodic architectures are packed by alternately normal-oriented flat-on crystals underneath the valley, periodically interfaced/branched with horizontal-oriented edge-on fibrils underneath the ridge. The oblique angles between the valley’s flat-on crystals with the branches are ca. 25–45° (depending on gradient inclines and bending), which is also proved by the azimuthal angle in microbeam X-ray diffraction. The grating-like strut-rib assembly in the PPDO cactus-arm-like ring bands is further proved by novel iridescence tests. Full article

With the rapid development of nanotechnology, the study of nanocomposites as electrode materials has significantly enhanced the scope of research towards energy storage applications. Exploring electrode materials with superior electrochemical properties is still a challenge for high-performance supercapacitors. In the present research article, we prepared a novel nanocomposite of tungsten trioxide nanoparticles grown over supported graphene oxide sheets and embedded with a poly(3,4-ethylenedioxythiophene) matrix to maximize its electrical double layer capacitance. The extensive characterization shows that the poly(3,4-ethylenedioxythiophene) matrix was homogeneously dispersed throughout the surface of the tungsten trioxide–graphene oxide. The poly(3,4-ethylenedioxythiophene)@tungsten trioxide–graphene oxide exhibits a higher specific capacitance of 478.3 F·g⁻¹ at 10 mV·s⁻¹ as compared to tungsten trioxide–graphene oxide (345.3 F·g⁻¹). The retention capacity of 92.1% up to 5000 cycles at 0.1 A·g⁻¹ shows that this ternary nanocomposite electrode also exhibits good cycling stability. The poly(3,4-ethylenedioxythiophene)@tungsten trioxide–graphene oxide energy density and power densities are observed to be 54.2 Wh·kg⁻¹ and 971 W·kg⁻¹. The poly(3,4-ethylenedioxythiophene)@tungsten trioxide–graphene oxide has been shown to be a superior anode material in supercapacitors because of the synergistic interaction of the poly(3,4-ethylenedioxythiophene) matrix and the tungsten trioxide–graphene oxide surface. These advantages reveal that the poly(3,4-ethylenedioxythiophene)@tungsten trioxide–graphene oxide electrode can be a promising electroactive material for supercapacitor applications. Full article

The rational fabrication of composite structures made of mixed components has shown great potential for boosting the energy density of supercapacitors. Herein, an elaborate hierarchical MOF-derived NiCo₂S₄@Mo-doped Co-LDH arrays hybrid electrode was fabricated through a step-wise method. By leveraging the synergistic effects of a uniform array of NiCo₂S₄ nanowires as the core and an MOF-derived porous shell, the NiCo₂S₄@Mo-doped Co-LDH hybrid electrode demonstrates an exceptional specific capacitance of 3049.3 F g⁻¹ at 1 A g⁻¹. Even at a higher current density of 20 A g⁻¹, the capacitance remains high at 2458.8 F g⁻¹. Moreover, the electrode exhibits remarkable cycling stability, with 91% of the initial capacitance maintained after 10,000 cycles at 10 A g⁻¹. Additionally, the as-fabricated asymmetric supercapacitor (ASC) based on the NiCo₂S₄@Mo-doped Co-LDH electrode achieves an impressive energy density of 97.5 Wh kg⁻¹ at a power density of 835.6 W kg⁻¹. These findings provide a promising approach for the development of hybrid-structured electrodes, enabling the realization of high-energy-density asymmetric supercapacitors. Full article

The Au ion implantation process has emerged as an effective and simple method to be utilized for the fabrication of opto-electronic materials and devices due to numerous fascinating features of Au nanoparticles such as surface plasmon resonance (SPR), large third-order nonlinearity and a fast response time. In this paper, we describe the fabrication of a novel Au nanoparticle saturable absorber (Au NP-SA) by embedding the Au NPs into a SiO₂ thin film using the ion implantation process, which shows excellent saturable absorption features due to the localized surface plasmon resonance (LSPR) effect of Au NPs. A stable and high-quality pulsed laser with a repetition rate of 33.3 kHz and a single pulse energy of 11.7 nJ was successfully constructed with the Au NP-SA. Both the stable operation characteristic of the obtained Q-switched pulsed laser and the high repeatability of the fabrication process of the Au NP-SA were demonstrated. In addition, the simple feasibility and maturity of the ion implantation process allow for the plasmonic nanoparticles to be easily integrated into other types of opto-electronic materials and devices to further improve their performance, and shows immense potential for the production of wafer-level products. Full article

Granular activated carbon (GAC) has proven to be an effective adsorbent for removing the chemical warfare agent sarin (GB) and simulants like Dimethyl methylphosphonate (DMMP). However, it comes with certain limitations, including inadequate contact efficiency, notable mass transfer resistance, and lower bed utilization efficiency. This study synthesized steel fiber-entrapped activated carbon composites (SFEACs), which exhibited a maximum adsorption capacity of 285.3 mg/g at 303 K. Compared with the packed bed (PB) filled with GAC, while the adsorption capacity of SFEACS decreased, there was a substantial increase in the adsorption mass transfer rate. These SFEACs were combined with GAC to create a structural fixed bed (SFB), which demonstrated excellent performance in DMMP removal. Under identical experimental conditions, the DMMP breakthrough curve of SFB exhibited a steeper profile compared to the packed bed (PB) filled with GAC at the same bed height, and the breakthrough time against DMMP vapor could be extended by 13.8%. Furthermore, the adsorption rate constant of the Yoon-Nelson model increased by more than 17.6%, and the unused bed length, according to the Wheeler–Jonas model, decreased by more than 14%. Full article