With the wide application of portable wearable devices, a variety of electronic energy storage devices, including microsupercapacitors (MSCs), have attracted wide attention. Laser-induced graphene (LIG) is widely used as electrode material for MSCs because of its large porosity and specific surface area. To further improve the performance of MSCs, it is an effective way to increase the specific surface area and the number of internal active sites of laser-induced graphene electrode materials. In this paper, N-doped polyimide/polyvinyl alcohol (PVA) as precursor was used to achieve in situ doping of nitrogen atoms in laser-induced graphene by laser irradiation. Through the addition of N atoms, nitrogen-doped laser-induced threedimensional porous graphene (N-LIG) exhibits large specific surface area, many active sites, and good wettability all of which are favorable conditions for enhancing the capacitive properties of laser-induced graphene. After assembly with PVA/H2SO4 as gel electrolyte, the high surface capacitance of the MSC device with N-LIG as electrode material is 16.57 mF cm− 2 at the scanning rate of 5 mV s− 1, which is much higher than the 2.89 mF cm− 2 of the MSC device with LIG as electrode material. In addition, MSC devices with N-LIG as electrode materials have shown excellent cyclic stability and flexibility in practical tests, so they have a high application prospect in the field of flexible wearable microelectronics.
We successfully synthesized a porous carbon material with abundant hexagonal boron nitride (h-BN) dispersed on a carbon matrix (p-BN-C) as efficient electrocatalysts for two-electron oxygen reduction reaction ( 2e− ORR) to produce hydrogen peroxide ( H2O2). This catalyst was fabricated via ball-milling-assisted h-BN exfoliation and subsequent growth of carbon structure. In alkaline solutions, the h-BN/carbon heterostructure exhibited superior electrocatalytic activity for H2O2 generation measured by a rotating ring-disk electrode (RRDE), with a remarkable selectivity of up to 90–97% in the potential range of 0.3–0.6 V vs reversible hydrogen electrode (RHE), superior to most of the reported carbon-based electrocatalysts. Density functional theory (DFT) simulations indicated that the B atoms at the h-BN heterostructure interface were crucial active sites. These results underscore the remarkable catalytic activity of heterostructure and provide a novel approach for tailoring carbon-based catalysts, enhancing the selectivity and activity in the production of H2O2 through heterostructure engineering.
The thermal conductivity (TC) of graphene-based/metal composites is currently not satisfactory because of the existence of large interfacial thermal resistance between graphene and metal originating from the strong scattering of phonons. In this work, 6063Al-alloy-based reduced graphene oxide (rGO) composite with strong covalent bonds interface was prepared via self-assembly, reduction, and electrophoresis-deposition processes by using 3-aminopropyl triethoxysilane (APTS) as a link agent. Structural characterizations confirmed the successful construction of strong Al-O-Si-O-C covalent bonds in the as-prepared 6063Al-Ag-APTS-rGO composite, which can promote the transfer of phonons in the interface. Benefiting from the unique structure, 6063Al-Ag-APTS-rGO (214.1 W/mK) showed obviously higher cross-plane TC than 6063Al (195.6 W/mK). Comparative experiments showed that 6063Al-Ag-APTS-rGO has better cross-plane TC than 6063Al/Ag/ APTS/rGO (196.6 W/mK) prepared via physical mixing of stirring process, evidencing the significance of electrophoresisdeposition (EPD) process on constructing strong covalent bonds for improving the heat dissipation performance. Besides, the effects of different rGO contents and test temperature on the TC of the composites and their corrosion resistance were also discussed. This work demonstrated a feasible strategy for the construction of metal–carbon interface composite with improved thermal performance.
Pyrolysis of methane is a carbon-economic method to obtain valuable carbon materials and COx- free H2, under the carbon peaking and carbon neutrality goals. In this work, we propose a methane pyrolysis process to produce graphite and H2 using bubble column reactor containing NiO/Al2O3 and NaCl–KCl (molten salt). The process was optimized by the different amounts of NaCl–KCl, the CH4/ Ar ratio and temperature, indicating that the CH4 conversation rate could reach 92% at 900 °C. Meanwhile, we found that the addition of molten salt could obtain pure carbon materials, even if the conversation rate of CH4 decreases. The analysis of the carbon products revealed that graphite could be obtained.
The raw material selected for this research was Brazil chestnut shells (BCs), which were utilized to gain porous carbon as a positive electrode for lithium–sulfur batteries (LSBs). The effects of N/S co-doped on the electrochemical properties of porous carbon materials were studied using thiourea as nitrogen and sulfur sources. The experimental results indicate that the N/S co-doped carbon materials have a higher mesopore ratio than the undoped porous carbon materials. The porous carbon material NSPC-2 has a lotus-like structure with uniform pore distribution. The N and S doping contents are 2.5% and 5.4%. The prepared N/S co-doped porous carbon materials were combined with S, respectively, and three kinds of sulfur carbon composites were obtained. Among them, the composite NSPC-2/S can achieve the initial specific discharge capacity of 1018.6 mAh g− 1 at 0.2 C rate. At 1 C rate, the initial discharge capacity of the material is 730.6 mAh g− 1, and the coulomb efficiency is 98.6% and the capacity retention rate is 71.5% after 400 charge–discharge cycles.
In recent years, the efficient and clean utilization of coal has been widely concerned by scholars at home and abroad. Despite the abundance of global coal resources, the deep utilization rate of coal is still insufficient. To address this challenge, it has been explored the development and preparation of coal-based high value-added carbonaceous materials. In the present study, a novel process was developed for the preparation of graphene using biphenyl sourced from low-rank coal. Using chemical vapor deposition (CVD) technology, it was successfully implemented for us to grow high-quality graphene on copper foils. The prepared graphene products were observed and characterized using Raman spectroscopy, optical microscopy and scanning electron microscopy techniques. The results of this research provide a new perspective for the utilization of low-rank coal resources.
Flexible self-supported laser-induced graphene (LIG) electrode devices were facilely fabricated through laser ablation technique by employing commercial polyimide film as the precursor material. Compared with the widely used traditional glassy carbon electrodes, the resulted LIG electrodes displayed abundant porous structure and surface defects. Notably, the onestep yielded LIG electrode devices were endowed with large electrochemically active surface area and accelerated electron transfer ability. Benefiting from its superior electrochemical property, these unmodified LIG electrodes exhibited remarkable enhanced electrochemical oxidation reactivity toward the food additive molecule Allura Red. Based on the augmented oxidation signal of Allura Red molecules on the LIG electrodes, a novel electrochemical sensor with high sensitivity for the detection of Allura Red was successfully developed. The sensor demonstrated a linear detection range spanning from 5 nM to 1 μM and exhibited a detection limit as low as 2.5 nM. Besides, the sensitivity was calculated to be 240.62 μA μM−1 cm− 2. More importantly, the sensor manifested outstanding stability, reproducibility, and practicality, further emphasizing its potential for real-world application.
Carbon dots (CDs) are versatile nanomaterials with tunable luminescent properties. We used a natural plant kaempferol as a carbon source to synthesize multicolor CDs by reacting it with various nitrogen sources. Blue, green, and red CDs (B-CDs, G-CDs, and R-CDs) with emission wavelengths of 445 nm, 510 nm, and 600 nm respectively were successfully synthesized. Their photoluminescence quantum yields of are up to 37.4%, 20.1%, and 30.8%, respectively. Surface analysis revealed abundant nitrogen groups influencing luminescence. B-CDs and G-CDs show excitation-dependent emissions, indicating a potential correlation between their luminescence and particle sizes, while R-CDs exhibit excitation-independent emission, suggesting they belong to molecular state CDs. All three CDs exhibit stable luminescent performance, as well as good salt resistance and photobleaching resistance. The practical application of multicolored CDs in anti-counterfeiting fluorescent inks was further explored. This work offers a straightforward, eco-friendly route to synthesize multicolor CDs.
This study investigates consumer experiences and word-of-mouth (WOM) intentions in luxury brand pop-up stores, including standalone and department store setups. Grounded in experience economy theory, this study examines the experiential elements based on the types of pop-up stores and the relationships among consumer experience, pop-up store image, and WOM intentions for each type. Data were collected from 300 visitors to luxury brand pop-up stores between January and July 2023 and analyzed using Smart PLS 4.0. The findings reveal several key insights. First, standalone pop-up stores offer educational and escapist experiences, while pop-ups within department stores have a single identified factor of consumer experience. Second, regardless of the store type, luxury pop-up store experiences significantly influence pop-up image perceptions. Third, luxury pop-up store image drives WOM intentions for both standalone and department store pop-ups. Notably, the unique image significantly impacts solely department store pop-ups and does not influence standalone pop-ups. Moreover, image perceptions in both pop-up store types do not significantly affect brand WOM intentions. Finally, WOM intentions for pop-up stores significantly influence WOM intentions for brands. This study contributes to the theoretical understanding of consumer experiences in luxury pop-up stores, providing practical insights for stakeholders in the luxury brand industry to enhance pop-up store image perceptions and WOM intentions.
Scabies, caused by an infestation of the skin with the itch mite (Sarcoptes scabiei), is highly contagious and classified as a prevalent neglected tropical diseases. The current diagnostic approach relies solely on clinical judgment based on symptoms, history, and microscopic observation by an experienced dermatologist. To enhance sensitivity and specificity, we developed an alternative method based on mite-derived DNA. Our method involves a quick DNA release from skin scraping samples and Loop-Mediated Isothermal Amplification (LAMP) targeting the scabies mite-specific DNA sequences, enabling diagnosis within 30 minutes. Importantly, no cross-reactivity was observed when the sample was contaminated by two house dust mite species, and false positives were barely detected. Currently, we are in the process of developing a Point-of-Care Testing (POCT) kit for a scabies survey targeting school-age children in Timor-Leste as a global health project.
Silage inoculants, crucial in modern silage production, comprise beneficial microorganisms, primarily lactic acid bacteria (LAB), strategically applied to forage material during ensiling. This study aimed to compare the effectiveness of various inoculants produced by different companies. Five treatments were evaluated, including a control group: T1 (Lactobacillus plantarum), T2 (Lactobacillus plantarum + Pediococcus pentosaceus), T3 (Lactobacillus plantarum + Pediococcus pentosaceus + Lactobacillus buchneri), T4 (Lactobacillus plantarum + Lactobacillus acidophilus + Lactobacillus bulgaricus), and T5 (Lactobacillus plantarum + Pediococcus pentosaceus + Enterococcus faecium). Italian ryegrass was harvested at the heading stage and treated with these silage inoculants. Samples were collected over a 60-day ensiling period. Co-inoculation with L. plantarum and P. pentosaceus (T2) resulted in significantly higher CP compared to the control group co-inoculation exhibited with resulted in Lactobacillus plantarum and Pediococcus pentosaceus in the T2 treatment exhibited higher CP content of 106.35 g/kg dry matter (DM). The T3 treatment, which included heterofermentative bacterial strains such as Lactobacillus buchneri, exhibited an increase in acetic acid concentration (11.15 g/kg DM). In the T4 treatment group, which utilized a mixed culture of Lactobacillus acidophilus and Lactobacillus bulgaricus, the NH3-N/TN content was observed to be the lowest (20.52 g/kg DM). The T5 containing Enterococcus faecium had the highest RFV (123) after 60 days. Expanding upon these findings, the study underscores not only the beneficial effects of particular inoculant treatments on silage quality but also underscores the potential of customized inoculation strategies in maximizing nutrient retention and overall silage preservation.
Carbon dots (CDs) are a novel type of fluorescent nanoparticles with a particle size smaller than 10 nm. They possess several advantageous properties, including excellent biocompatibility, light stability, water solubility, and low toxicity. CDs have been widely researched in recent years. As a treasure of ancient Chinese science, traditional Chinese medicine (TCM) is rich in various active ingredients and has a variety of pharmacodynamic effects, which have been used for thousands of years. TCM-CDs prepared with TCM as carbon source can create some special functions and then may play a greater medicinal value. The purpose of this review was to engage in an in-depth conversation about the use of TCM-CDs in medical therapy and bioimaging. Firstly, this study provides a comprehensive exploration of different synthesis methods for TCM-CDs, comparing their respective advantages and disadvantages. Subsequently, the intrinsic pharmacological activity of TCMCDs, encompassing antibacterial, hypoglycemic, hemostatic, anticancer, and anti-inflammatory effects, is mainly discussed, alongside their underlying mechanisms of action. Additionally, investigations into in vitro imaging of diverse cell types and the distribution and uptake of TCM-CDs under in vivo imaging guidance are presented. Finally, the significance of TCM-CD research, key challenges and issues within this field, and future directions for development are summarized and outlined.
The emergence of ferrous-medium entropy alloys (FeMEAs) with excellent tensile properties represents a potential direction for designing alloys based on metastable engineering. In this study, an FeMEA is successfully fabricated using laser powder bed fusion (LPBF), a metal additive manufacturing technology. Tensile tests are conducted on the LPBF-processed FeMEA at room temperature and cryogenic temperatures (77 K). At 77 K, the LPBF-processed FeMEA exhibits high yield strength and excellent ultimate tensile strength through active deformation-induced martensitic transformation. Furthermore, due to the low stability of the face-centered cubic (FCC) phase of the LPBFprocessed FeMEA based on nano-scale solute heterogeneity, stress-induced martensitic transformation occurs, accompanied by the appearance of a yield point phenomenon during cryogenic tensile deformation. This study elucidates the origin of the yield point phenomenon and deformation behavior of the FeMEA at 77 K.
This research investigated the preparation of activated carbon derived from Krabok (Irvingia malayana) seed shells to improve the quality of crude glycerol obtained during biodiesel production. The activated carbon was prepared using a dry chemical activation method with NaOH, utilizing an innovative biomass incinerator. The results revealed that the resulting KC/AC-two-step exhibited favorable physicochemical adsorption properties, with a high surface area of 758.72 m2/g and an iodine number of 611.10 mg/g. These values meet the criteria of the industrial product standard for activated carbon No. TIS 900-2004, as specified by the Ministry of Industry in Thailand. Additionally, the adsorption efficiency for methylene blue reached an impressive 99.35 %. This developed activated carbon was then used to improve the quality of crude glycerol obtained from biodiesel production. The experimental results showed that the KC/AC-two-step increased the purity of crude glycerol to 73.61 %. In comparison, commercially available activated carbon (C/AC) resulted in a higher crude glycerol purity of 81.19 %, as analyzed by the GC technique. Additionally, the metal content (Zn, Cu, Fe, Pb, Cd, and Na) in purified glycerol using KC/AC-two-step was below the standards for heavy metals permitted in food and cosmeceuticals by the Food and Drug Administration of Thailand and the European Committee for Food Contact Materials and Articles. As a result, it can be inferred that Krabok seed shells have favorable properties for producing activated carbon suitable as an adsorbent to enhance crude glycerol purity. Furthermore, the improved crude glycerol from this research has potential for various industrial applications.
In this study, the refinement of Multiwalled Carbon Nanotubes (MWCNTs) derived from chemical vapor decomposition is investigated. An ultrasonic pretreatment method is employed to disentangle carbon and metal impurities intertwined with MWCNTs. The pretreated MWCNTs exhibit a marginal decrease in C–O/C = O content from 8.9 to 8.8%, accompanied by a 2.5% increase in sp3 carbon content, indicating a mildly destructive pretreatment approach. Subsequently, selective oxidation by CO2 and hydrochloric acid etching are utilized to selectively remove carbon impurities and residual metal, respectively. The resulting yield of intact MWCNTs is approximately 85.65 wt.%, signifying a 19.91% enhancement in the one-way yield of pristine MWCNTs. Notably, the residual metal content experiences a substantial reduction from 9.95 ± 2.42 wt.% to 1.34 ± 0.06 wt.%, representing a 15.68% increase in the removal rate. These compelling findings highlight the potential of employing a mild purification process for MWCNTs production, demonstrating promising application prospects.
In this work, the trend in the performance of carbon fiber (CF) and its composite during self-polymerization of polydopamine (PDA) at carbon fiber surface was investigated by varying the self-polymerization time of dopamine in an aqueous solution. Research has shown that the PDA coating elevated the surface roughness and polarity of the inert fiber. The tensile strength of single carbon fiber was significantly improved, especially after 9 h of polydopamine self-polymerization, increasing by 18.64% compared with that of desized carbon fiber. Moreover, the interlaminar shear strength (ILSS) of CF-PDA9-based composites was 35.06% higher than that of desized CF-based composites. This research will provide a deep insight into the thickness and activated ingredients of dopamine oxidation and self-polymerization on interfacial compatibility of carbon fiber/epoxy resin composites.