Ammonia is a potential fuel for producing and storing hydrogen, but its usage is constrained by the high cost of the noble metal catalysts to decompose NH3. Utilizing non-precious catalysts to decompose ammonia increases its potential for hydrogen production. In this study, carborundum (SiC)-supported cobalt catalysts were prepared by impregnating Co3O4 nanoparticles (NPs) on SiC support. The catalysts were characterized by high-resolution transmission electron microscope, X-ray photoelectron spectroscopy, temperature programmed reduction, etc. The results show that the large specific surface area of SiC can introduce highly distributed Co3O4 NPs onto the surface. The amount of Co in the catalysts has a significant effect on the catalyst structure, particle size and catalytic performances. Due to the interaction of cobalt species with SiC, the 25Co/SiC catalyst provided the optimal ammonia conversion of 73.2% with a space velocity of 30,000 mL gcat −1 h− 1 at 550 °C, corresponding to the hydrogen production rate of 24.6 mmol H2 gcat −1 min− 1. This research presents an opportunity to develop highly active and cost-effective catalysts for hydrogen production via NH3 decomposition.

With the rapid development of flexible wearable electronic products, flexible all graphene-based supercapacitors (FGSCs) with reduced graphene oxide rGO//graphene oxide (GO)//rGO structure have attracted substantial attention due to their unique structures and energy storage mechanism. However, restricted by design idea and preparation technology, improvement of capacitance performance for the FGSCs is not obvious recently. Herein, we demonstrate that an interface integration strategy of constructing the high-performance FGSCs with compact structure. Hydroquinone (HQ)-modified rGO (HQ-rGO) films (electrode materials) and sulfuric acid-intercalated GO films (electrolyte/separator) are assembled into the FGSCs utilizing hydrogen bonding and capillary contractility. The HQ further improves the electrochemical capacitance of electrode materials. The synergistic effect of the hydrogen bonding and capillary contractility guarantees compact and stable structure of the device. The resulting FGSCs exhibit an excellent areal capacitance of 804.6 mF cm− 2 (@2 mA cm− 2) and 441 mF cm− 2 (@30 mA cm− 2), and their highest energy and power densities can achieve 109.5 μWh cm− 2 and 21,060 μW cm− 2, respectively. These performances are superior to other all-in-one graphene-based SCs reported. Therefore, the construction technology of the FGSCs is a promising for developing all graphene-based SCs with high-performance.

Renewed interest in the reinforced carbon graphite composites has intrigued the community in the advanced materials fields. In this work, we present a simple carbon nanofibers reinforced carbon graphite composites synthetic method by incorporating mixture of coal tar pitch, synthetic graphite, pitch coke and the dispersion liquid of carbon nanofibers via liquid-phase mixing process. The impact of carbon nanofiber utilization on the microstructures and mechanical properties of carbon graphite composites are studied systematically. The covalent surface modification of carbon nanofibers effectively improves its microstructure and thereby promotes the carbon graphite composites’ dispersion behavior. We propose that a small amount of carbon nanofibers could promote the carbonization process of carbon graphite composites, facilitating the densification of carbon graphite composites and reducing the undesired open porosity. The amount of 0.7 wt % of carbon nanofiber concentration allows the enhancement of bend and compressive strength of carbon graphite composites up to 36.50 MPa and 60.46 MPa, increased by 167.9% and 146.9% compared with the pure carbon graphite composite, respectively. Our findings can be rationalized due to the improvement in the mechanical strength of carbon graphite composites could be attributed due to pull-out of carbon nanofibers from the matrix and bridging effect across the crack pores within the matrix.

Biomass carbon materials with high rate capacity have great potential to boost supercapacitors with cost effective, fast charging– discharging performance and high safety requirements, yet currently suffers from a lack of targeted preparation methods. Here we propose a facile FeCl3 assisted hydrothermal carbonization strategy to prepare ultra-high rate biomass carbon from apple residues (ARs). In the preparation process, ARs were first hydrothermally carbonized into a porous precursor which embedded by Fe species, and then synchronously graphitized and activated to form biocarbon with a large special surface area (2159.3 m2 g− 1) and high degree of graphitization. The material exhibited a considerable specific capacitance of 297.5 F g− 1 at 0.5 A g− 1 and outstanding capacitance retention of 85.7% at 10 A g− 1 in 6 M KOH, and moreover, achieved an energy density of 16.2 Wh kg− 1 with the power density of 350.3 W kg− 1. After 8000 cycles, an initial capacitance of 95.2% was maintained. Our findings provide a new idea for boosting the rate capacity of carbon-based electrode materials.

Combination of liquid-phase exfoliation and hydrothermal method has progressed in recent years mainly on production of 2D materials. In this study, graphene was successfully synthesized via combinatorial of liquid-phase exfoliation and hydrothermal method with the aid of various conductive surfactants perylene-3, 4, 9, 10-tetracarboxylate (PTCA), lithium perylene-3, 4, 9, 10-tetracarboxylate (LiPTCA) and sodium perylene-3, 4, 9, 10-tetracarboxylate (NaPTCA). The effect of the lithium ( Li+) and sodium ( Na+) cations toward the efficiency of the graphene exfoliation process and its electrical properties was thoroughly investigated. Based on the characterization techniques, it is revealed that NaPTCA is the ideal conductive surfactant to exfoliate graphene sheets. X-ray diffraction spectra verified that the Na+ cation certainly can enhance the exfoliation process by expanding the interlayer spacing. The lateral size of the graphene sheets with Na-PTCA surfactant was the smallest (4.17 μm) as observed from SEM micrograph. The maximum concentration of the graphene yield was achieved up to 0.151 mgmL− 1 in NaPTCA surfactant alongside with excellent electrical conductivity of 746.27 Sm− 1 and relevant specific capacitance of 129 Fg− 1.

Transition-metal phosphides (TMPs), a promising anode material for lithium-ion batteries (LIBs), are limited in application because of its serious volume effect in the cycle. In this work, a simple electrospinning strategy was proposed to restrict the grain size of CoP nanocrystals by nano-confined effect of carbon nanofibers with ligands. The addition of ligands not only could realize the uniform dispersion of CoP nanocrystals, but also strengthen the bond between the metals and carbon nanofibers. As a result, the CoP/CNF composite exhibits excellent lithium storage performance, and its reversible specific capacity could reach 1016.4 mAh g− 1 after 200 cycles at a current density of 200 mA g− 1. The research is anticipated to provide a new idea for the preparation of anode materials for lithium ion batteries.

Hydrogen energy is a promising source of renewable and clean energy for various industries, such as chemical, automobile, and energy industries. Electrolysis of water is one of the basic methods for the production of hydrogen energy. However, the high overpotential of the oxygen evolution reaction (OER) in water electrolysis has hindered the effective production of hydrogen using this method. Thus, the development of high-efficiency non-precious metal-based electrocatalysts for OER is extremely significant. In this study, we adopted a one-step hydrothermal method to fabricate Ni-based catalysts with N/Sdual doped graphene oxide/carbon nanotube (GO/CNT) supports using thiourea ( CH4N2S) and urea as the S source and the N source. It was observed that the amount of thiourea utilized in the synthesis of the catalyst affected the morphology, composition, and the electrochemical properties of the catalyst. For a GO/CNT-to-thiourea mass ratio of 1:10, the catalyst exhibited the highest activity, where the OER overpotential was 320 mV at a current density of 10 mA/cm2. This was attributed to the high specific surface area, high conductivity, and fast electron transport channels of the N/S-dual doped GO/ CNT composite. Furthermore, sulfurization of the Ni particles to form nickel sulfide played a significant role in enhancing the catalytic performance.

Understanding molting process in subterranean termites is a critical step to implement successful control program as chitin synthesis inhibitor baits interfere molting process of termites. In the present study, we report detailed molting process in Reticulitermes speratus kyushuensis Morimoto, 1968 that foraging workers start fasting period 5 days after they were collected and finished their entire molting process for the next 5 to 6 days. Ecdysis took less than an hour, specifically 9.2 ± 4.9 minutes from jack-knife posture to separation of the antenna and 36.6 ± 8.5 minutes from separation of the antenna to regain mobility. We believed relatively short time window of molting process in R. speratus kyushuensis may affect lengthy colony elimination time.

The evolvement in the microstructure and electrical properties of PAN-based carbon fibers during high-temperature carbonization were investigated. The study showed that as the heat treatment temperature increases, the change of carbon fiber resistivity around 1100 °C can be divided into two stages. In the first stage, the carbon content of the fiber increased rapidly, and small molecules such as nitrogen were gradually released to form a turbostratic of carbon crystal structure. The resistivity dropped rapidly from 3.19 × 10− 5 Ω·m to 2.12 × 10− 5 Ω·m. In the second stage, the carbon microcrystalline structure gradually became regular, and the electron movement area gradually became larger. At this time, the resistivity further decreases, from 2.12 × 10− 5 Ω·m to 1.59 × 10− 5 Ω·m. During carbonization, the tensile strength of carbon fiber first increased and then decreased. This is because the irregular and disordered graphite structure is formed first. As the temperature rose, the graphite layer spacing decreased and the grain thickness gradually increases. The modulus also gradually increased.

We report the use of face mask materials as a carbon precursor for the synthesis of multi- and single-walled carbon nanotubes (CNTs) in an open-loop chemical recycling process. Novel surgical mask precursors were suspended in toluene and injected into a chemical vapor deposition reactor previously optimized for CNT production using liquid injection. The CNTs were collected and characterized using resonant Raman spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) before being turned into fibrils that were tested for electrical conductance. Once confirmed and repeated for statistical accuracy, a CNT-based Ethernet cable was manufactured and tested using iPerf3 for uplink and downlink speeds exceeding broadband standards worldwide. Radial breathing modes from Raman spectroscopy indicate single walled CNTs (SWCNTs) with diameters ranging from 0.8 to 1.55 nm and this matches well with TEM observations of SWCNTs with 1.5 nm diameter. This work pushes the horizon of feedstocks useful for CNT and SWCNT production in particular; this work demonstrates upcycling of materials fated for disposal into materials with positive net value and plenty of real-world applications.

The progress of science and technology has driven the development of the society, and the application of threedimensional simulation technology in all walks of life has greatly improved people's life. Maritime affairs is an important part of comprehensive transportation. The improvement of maritime supervision and service level is conducive to the construction of domestic first-class economic law enforcement system and international leading maritime management institutions. Now the application of 3D simulation technology to maritime supervision is studied, aiming to improve the quality and efficiency of supervision, make maritime supervision more convenient and have further guarantee. Maritime supervision of ship environment is often more troublesome than personnel management. In the process of monitoring and control, many uncontrollable environmental factors greatly increase the difficulty of supervision, among which the port environment is more complex, which is a difficulty of monitoring and control in maritime supervision. This paper uses MapInfo Professional, Win Topo, Multigen Creator and other operating software to construct the Qingdao port visual simulation environment. The port topographic cloud map of Qingdao Port was captured, and the collected image information was converted into data through MapInfo Professional and Win Topo software, and then modeled by Multigen Creator software. After completing the general terrain outline, the established simulation scene was made more realistic and realistic through some detail processing and optimization means. By describing the establishment of 3D simulation terrain in Qingdao Port, the application status of the simulation technology in ship environment and port management is reflected, which provides a reference for the deeper application of 3D simulation technology in maritime supervision.

A composite photocatalyst of zinc oxide (ZnO) nanoparticles decorated with different content of reduced graphene oxide (rGO) was prepared via a simple and facile one-step method in this paper. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectra, and UV–Vis diffuse reflection spectroscopy (UV–Vis DRS) were used to characterize the crystal structure, morphology and optical properties of the rGO–ZnO composite photocatalyst. The photocatalytic properties of the composites were investigated using methyl orange (MO), a typical orange compound, as a test pollutant. The results showed that rGO–ZnO composites displayed significantly enhanced photocatalytic activity in MO degradation than pure ZnO, and the pseudo-first-order kinetic constant on the optimal rGO–ZnO composite was 14 times as great as that on pure ZnO. The enhanced photocatalytic ability of the rGO-ZnO composites was mainly benefited from the high specific surface area and high conductivity of rGO, which facilitated efficient charge separation in the rGO-ZnO nanocomposite.