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In this work, we developed a simple route to synthesize green fluorescence carbon nanoparticles (FCPs) at room temperature with dopamine and p-phenylenediamine as raw materials. The FCPs exhibited a salient fluorescence emission peak at 525 nm and well stability in the intricate surroundings. Only Cu2+ ions could significantly inhibited the fluorescence of FCPs and could be successfully detected in the concentration scope of 0–200 µmol·L−1 based on the fluorescence quenching of FCPs. The Cu2+ ion-quenched fluorescence of FCPs system can be further recovered by the addition of dipicolinic acid (DPA) and could be utilized for DPA detection within the dynamic scope of 10–150 µmol·L−1. [ABSTRACT FROM AUTHOR]

This work aims at investigating the nonlinear transient response of fluid-conveying pipes made of graphene nanoplatelet (GPL)-reinforced composite (GPLRC) under blast loads and in a thermal environment. A modified Halpin–Tsai model is used to approximate the effective Young's modulus of the GPLRC pipes conveying fluid; the mass density and Poisson's ratio are determined by using the Voigt model. A slender Euler–Bernoulli beam is considered for modeling the pipes conveying fluid. The vibration control equation of the GPLRC pipes conveying fluid under blast loads is obtained by using Hamilton's principle. A set of second-order ordinary differential equations are obtained by using the second-order Galerkin discrete method and are solved by using the adaptive Runge–Kutta method. Numerical experiments show that GPL distribution and temperature; GPL weight fraction; pipe length-to-thickness ratio; flow velocity; and blast load parameters have important effects on the nonlinear transient response of the GPLRC pipes conveying fluid. The numerical results also show that due to the fluid–structure interaction, the vibration amplitudes of the GPLRC pipes conveying fluid decay after the impact of blast loads. [ABSTRACT FROM AUTHOR]

Biomass‐based carbon materials have attracted much attention in the field of microwave absorption because of their light weight, environmental friendliness, low cost and high efficiency. In this work, carbon matrix of porous microtubule structure with different magnetic particles was synthesized from natural luffa sponge by a simple calcination process. The carbon matrix possesses hierarchical porous structures including micrometer‐scale tubular channels, nanometer‐scale macrospores, mesopores and micropores, of which microspores are the most. The Fe3O4, FeO/α‐Fe, α‐Fe/γ‐Fe and α‐Fe/Fe3C particles were formed in the temperature range of 700–1000 °C. The porous carbon/α‐Fe@Fe3C composites obtained at 1000 °C exhibit excellent microwave absorption (MA) performance, its minimum reflection loss can reach −48.9 dB with only a thickness of 1.5 mm, and the effective absorption bandwidth (RL≤−10 dB) is 3.86 GHz. The porous structure, synergies between dielectric loss and magnetic loss, high attenuation constant are the key factors for good MA performance. [ABSTRACT FROM AUTHOR]

DNA detection plays an important role in early diagnosis of genetic disease. The conventional detection methods of DNA are based on expensive equipment, which do not meet the demands of developing countries. Thus, we developed a colorimetric method, which could be observed with naked eye and used copper nanoclusters for cost-effective. Moreover, the target of this method is the DNA in Hepatitis B virus that is one of the most popular chronic viral infections in developing countries over the past years. Our method was sensitive and the limit of detection was 12 × 10 9 molecules. Three-base-pair mismatches target DNA was detected easily. These results revealed the favorable sensitivity and selectivity of this approach. Most importantly, our method may have potential applications in correct diagnosis of genetic disease and monitoring of gene therapy in the poverty-stricken areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu-CaTiO 3 hybrid photocatalysts were synthesized by a facile solvothermal method. • Cu-CaTiO 3 hybrid exhibited improved capability for solar-to-H 2 evolution. • The formed Schottky junction between CaTiO 3 and Cu facilitated electron-hole separation. • The cocatalytic effect of Cu also played important roles in enhancing hydrogen production. Photocatalytically splitting water to hydrogen production is a great potential for addressing the issue of energy crisis and environmental pollution. Metal-semiconductor hybrid photocatalyst has attracted increasing attention, and especially non-noble metal decoration is one of promising strategies to promote photoinduced electron-hole pairs separation for an efficient solar-to-hydrogen evolution. Herein, a facile solvothermal approach was successfully employed to prepare calcium titanate (CaTiO 3) nanorods with decoration of copper particles. The composition and morphology characterization showed that the Cu particle was deposited on the surface of CaTiO 3 nanorod. The as-synthesized CaTiO 3 /Cu composites exhibited promoted solar-to-hydrogen performance and their activities varied from copper loading amounts. The optimized CaTiO 3 /Cu-0.05 achieved a hydrogen evolution rate of 251 µmol g−1 h−1 , which was much higher than that of bare CaTiO 3. Based on the photoluminescence spectra and photocurrent density measurements, it was proposed that efficient separation of photogenerated charges was achieved between the CaTiO 3 nanorod and Cu nanoparticles, which promoted water splitting for H 2 production. This work further confirms that metallic Cu decoration is an efficient approach to promote photocatalytic H 2 production performance of semiconductor photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • The dual emission polymer carbon nanoparticles PDA-OPD were synthesized. • The PDA-OPD exhibited dual emission peaks at 460 nm and 540 nm upon single excitation wavelength. • The PDA-OPD can be used for detection of pH value in the range from 3.0 to 7.4. • The PDA-OPD can be used for detection of bilibrubin in the alkaline environment. Herein, we prepared a novel fluorescent polymer carbon nanoparticles by polymerizing dopamine (DA) and o-phenylenediamine (OPD) through oxidation of hydrogen peroxide. In a neutral environment, the synthesized fluorescent polymer carbon nanoparticles (PDA-OPD) exhibited two emission peaks at 460 nm and 540 nm with 400 nm excitation wavelength. In an acidic environment, the fluorescence emission peaks of PDA-OPD at 540 nm showed an obvious fluorescence quenching, and there existed a good linear relationship between the fluorescence ratio F 540 /F 460 and environment pH value. In an alkaline environment, the fluorescence emission peak at 460 nm showed obvious fluorescence quenching after the addition of bilirubin, while a novel fluorescence emission peak at 560 nm emerged gradually. The PDA-OPD could be also used to detect bilirubin in the range of 0–400 μmol·L−1. [ABSTRACT FROM AUTHOR]

[Display omitted] Developing an efficient and low-cost oxygen reduction electrocatalyst is essential for the application of aqueous zinc-air batteries (ZABs). Herein, we report a facile adsorption-confined pyrolysis strategy to fabricate the hybrid electrocatalyst (denoted as Co 9 S 8 /Co SA -PC) by embedding Co 9 S 8 nanoparticles into Co single atoms (Co-SAs) anchored porous carbon sheets for boosting oxygen reduction reaction (ORR) durability. In this strategy, the Co2+ ions are first absorbed into oxygen-rich porous carbon nanosheets and further form the Co-SAs with the help of thiourea in the following pyrolysis procedure, which is believed to be able to confine the generated Co 9 S 8 nanoparticles into carbon frameworks due to their interface interaction. Benefiting from the synergistic effect of different components, the obtained Co 9 S 8 /Co SA -PC electrocatalyst for ORR exhibits outstanding catalytic activity with a half-wave potential of 0.82 V and a distinguished long-term durability with a current retention of 80 % after cycling 80 h under alkaline conditions, which is superior to commercial Pt/C. Moreover, the assembled ZABs with Co 9 S 8 /Co SA -PC as cathodic catalyst deliver a high specific capacity of 764 mAh g Zn −1 at 10 mA cm−2 and the outstanding peak power density of up to 221.4 mW cm−2. This work provides a novel structure design strategy to prepare transition metal sulfide-based electrocatalysts with superior durability for ORR. [ABSTRACT FROM AUTHOR]

Wound dressings provide barrier protection during wound treatment while providing an environment suitable for wound healing. However, traditional wound dressings have disadvantages, such as easily adhering to wounds, poor barrier effects, and poor haemostasis. Therefore, it is of great significance to design a new wound dressing that does not cause further injury, has good antibacterial effect and promotes wound healing in view of the disadvantages of traditional wound dressings. In this paper, silver nanoparticles (AgNPs) were reduced by in situ reduction with sodium alginate (SA), and construct a silver-loaded PVA/SA/CMCS hydrogel antibacterial wound dressing. The properties of antibacterial hydrogel were evaluated. The results show that SA can successfully reduce AgNPs, and the particle size is small and uniform, which meets the requirements of antibacterial material. The AgNPs are evenly distributed inside the hydrogel and have stable performance. The silver-loaded hydrogel was formed uniform pores inside the material, and had excellent water absorption and water retention, which can absorb a large amount of wound exudate while maintaining a moist wound environment. The antibacterial hydrogel exhibited good mechanical properties, antibacterial activity and biocompatibility. In summary, the silver-loaded hydrogel is an ideal wound dressing. • A safer method for in-situ reduction of nanometer silver was adopted. • The mechanism of reduction is analyzed. • The proportion of PVA, CMCS, SA and AgNPs was introduced. • The antibacterial and biocompatibility were excellent. [ABSTRACT FROM AUTHOR]

Rational design and manufacture of encapsulated Pt@HCS catalysts for efficient benzene elimination under SO 2 containing conditions. [Display omitted] • Pt nanoparticles are uniformly encapsulated in a hollow carbon shell. • Pt@HCS shows excellent benzene oxidation properties, even in the presence of SO 2 , the benzene conversion rate can be stable at 100% for a long time. • The porous hollow carbon sphere structure significantly enhances the adsorption of benzene. • The abundant OH groups on the carbon shell surface preferentially capture SO 2 and prevent it from entering the interior of the catalyst. In the catalytic combustion of volatile organic compounds (VOCs) using noble metal catalysts, resistance to SO 2 poisoning poses a significant challenge. To tackle this problem, Pt nanoparticle catalysts encapsulated in hollow carbon spheres (Pt@HCS catalysts) are synthesized. The Pt@HCS catalyst exhibits excellent benzene conversion, achieving 100 % conversion at 165 °C under an air velocity of 20,000 mL/(g h). Compared to the conventional supported Pt/HCS catalyst, the Pt@HCS catalyst demonstrates a significantly improved resistance to SO 2 poisoning. In the presence of 25 ppm SO 2 , the Pt@HCS catalyst is capable of maintaining a 100 % benzene conversion rate within 24 h, whereas the conversion rate of Pt/HCS drops substantially to approximately 52 %. It is confirmed that the hollow porous structure provided a larger specific surface area and more adsorption sites, thereby facilitating benzene oxidation. More importantly, in situ DRIFTS reveals that the adsorption and desorption processes of SO 2 , along with the generation of substances like SO 3 2−, are strictly limited to the surface of the carbon shell, thereby preserving the integrity of the internal reaction environment. Multiple characterizations combined with density functional theory (DFT) have demonstrated a unique separation effect over Pt@HCS, whereby the hydroxyl groups on the carbon shell preferentially capture SO 2 while allowing benzene molecules to enter the cavities of the catalyst. In this way, any internal ingress of SO 2 and competition with benzene for Pt adsorption is effectively avoided. This study offers a potential solution to enhance the performance of noble metal catalysts in the presence of sulfur compounds. [ABSTRACT FROM AUTHOR]

A fluorescent suspension array combining digital encoding and molecular imprinting technologies was applied for multiplexed detection of phenols in aqueous medium. In this assay, nanomaterials such as silver (Ag), cuprous oxide (Cu 2 O), magnesium oxide (MgO), and zinc oxide (ZnO) were assembled on microbeads as digital encoding signal sources, then, (Digital encoding signal sources were produced by assembling silver (Ag), cuprous oxide Cu2O), magnesium oxide (MgO), and zinc oxide (ZnO) on microbeads. Molecular imprinted nanoparticles based on CdSe/ZnS quantum dots with various emission wavelengths (525, 565 and 585 nm) were grafted on the encoded beads through electrostatic adsorption and were used as the sensing units. The decoding spectra of the suspension array were stimulated and collected by a home-built laser induced breakdown spectroscopy system. The resulted spectra were transformed into digital sequences for encoding. As demonstrated in the gradient detections to various phenol solutions in concentration range of 0.98–62.5 μg/mL, the functionality of the suspension array was proven in the control experiments between the parent sensor beads and the molecular imprinting silica nanoparticles assembled sensor beads. Furthermore, the selectivity of suspension array was verified by the mixed adsorption experiments conducted in multicomponent analytes. [ABSTRACT FROM AUTHOR]

To achieve the dual-channel (analog and digital) encoding, microbeads assembled with quantum dots (QDs) and element coding nanoparticles (ECNPs) have been prepared. Dual-spectra, including fluorescence generated from quantum dots (QDs) and laser induced breakdown spectrum obtained from the plasma of ECNPs, including AgO, MgO and ZnO nanoparticles, has been adopted to provide more encoding amounts and more accurate dual recognition for encoded microbeads in multiplexed utilization. The experimental results demonstrate that the single microbead can be decoded in two optical channels. Multiplexed analysis and contrast adsorption experiment of anti-IgG verified the availability and specificity of dual-channel-coded microbeads in bioanalysis. In gradient detection of anti-IgG, we obtained the linear concentration response to target biomolecules from 3.125 × 10 −10  M to 1 × 10 −8  M, and the limit of detection was calculated to be 2.91 × 10 −11  M. [ABSTRACT FROM AUTHOR]

Graphitic carbon nanocages (GCNCs) with hierarchical pore structure have been synthesized by a simple low temperature carbonization process. Bio-renewable lignin was introduced as a low-cost and industrially available precursor for the first time. The products were characterized by X-ray diffraction (XRD), nitrogen adsorption–desorption isotherms, transmission electron microscopy (TEM) and Raman spectrum. XRD pattern and Raman spectrum showed that the product had a high degree of graphitization crystallinity. TEM indicated that the GCNCs have a hierarchical pore structure with graphitic frameworks. CO 2 capture tests approved that the GCNCs exhibited a pretty elevated adsorption capacity (28.7 mg g − 1 ), which can be attributed to the hollow nanocage structure and hierarchical porosity of lignin based GCNCs. [ABSTRACT FROM AUTHOR]