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Molybdenum disulfide(MoS2) has a special structure and excellent mechanical properties, making it a promising reinforcing filler for polymers. Carbon dots (CDs) have good antioxidant properties, and the addition of CDs during the synthesis of MoS2 can affect its morphology and size. In this work, a new one-step hydrothermal synthesis process was employed to prepare CDs/MoS2 hybrid particles. Thiourea, sodium molybdate, and glucose were employed as sources of sulfur, molybdenum, and carbon, respectively. The structure and morphology of MoS2 and CDs/MoS2 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), mapping surface scanning (SEM–EDS), and Fourier transform infrared spectroscopy (FTIR). The results show that the prepared 2H-MoS2 is stacked into flower-like spheres with size around 2–10 μm; with the formation of CDs, the size of MoS2 rapidly decreases to less than 1 μm and the CDs are evenly distributed on its surface with mass ratio of 40.2% (CDs in CDs/MoS2). Subsequently, the CDs/MoS2 were used as reinforcing fillers for natural rubber (NR) latex. The results of mechanical properties show that tear strength, tensile strength, modulus, and elongation at break are increased by the addition of CDs/MoS2 in a very lower loading, and the maximum increment ratio is 45.6% and 12.1% when compared to NR-0; the dynamic mechanical analysis and cross-link density results indicated that the CDs/MoS2 can simultaneously improve rigidity and elasticity of NR. The thermal stability results suggest that the CDs/MoS2 shows positive effects on thermal stability of NR. [ABSTRACT FROM AUTHOR]

Inorganic nitrogen oxide (NOx) species, such as NO, NO2, NO3−, NO2− generated from the decomposition of organic matters, volcanic eruptions and lightning activated nitrogen, play important roles in the nitrogen cycle system and exploring the origin of life. Meanwhile, excessive emission of NOx gases and residues from industry and transportation causes troubling problems to the environment and human health. How to efficiently handle these wastes is a global problem. In response to the growing demand for sustainability, scientists are actively pursuing sustainable electrochemical technologies powered by renewable energy sources and efficient utilization of hydrogen energy to convert NOx species into high‐value organonitrogen chemicals. In this minireview, recent advances of electrocatalytic systems for NOx species valorization in organonitrogen synthesis are classified and described, such as amino acids, amide, urea, oximes, nitrile etc. that have been widely applied in medicine, life science and agriculture. Additionally, the current challenges including multiple side reactions and complicated paths, viable solutions along with future directions ahead in this field are also proposed. The coupling electrocatalytic systems provide a green mode for fixing nitrogen cycle bacteria and bring enlightenment to human sustainable development. [ABSTRACT FROM AUTHOR]

Continuous large amounts of precipitation can lead to a rapid increase in the water content of concrete in village building foundations, which can adversely affect the mechanical properties, such as the compressive strength of concrete. There are few experimental studies on the compressive stochastic mechanical properties of concrete in the wet state after considering different soaking times (different water contents and saturations), but there is no corresponding stochastic damage principal structure model. In this study, the mechanical properties of concrete under different immersion times were tested to obtain the mechanical properties of the concrete degradation law, and the random damage intrinsic model of wet concrete was established. The results of this paper were compared with the classical test results from the literature to verify the validity of the model. The results show that the proposed stochastic damage model is able to consider both the effects of the saturation and the damage behavior of wet concrete under compression, which is beneficial to the structural design and maintenance protection of village buildings in areas with abundant precipitation. [ABSTRACT FROM AUTHOR]

Pyridine oximes produced from aldehyde or ketone with hydroxylamine (NH2OH) have been widely applied in pharmaceutics, enzymatic and sterilization. However, the important raw material NH2OH exhibits corrosive and unstable properties, leading to substantial energy consumption during storage and transportation. Herein, this work presents a novel method for directly synthesizing highly valuable pyridine oximes using in situ generated NH2OH from electrocatalytic NO reduction with well‐design nanofiber membranes (Al‐NFM) derived from NH2‐MIL‐53(Al). Particularly, 2‐pyridinealdoxime, the precursor of antidote pralidoxime (2‐PAM) for nerve agents suffering from scarcity and high cost, was achieved with a Faraday efficiency up to 49.8 % and a yield of 92.1 %, attributing to the high selectivity of NH2OH production on Al‐NFM, further easily reacted with iodomethane to produce 2‐PAM. This study proposes a creative approach, having wide universality for synthesizing pyridine and other oximes with a range of functional groups, which not only facilitates the conversion of exhaust gas (NO) and waste water (NO2−) into valuable chemicals especially NH2OH production and in situ utilization through electrochemistry, but also holds significant potential for synthesis of neuro detoxifying drugs to humanity security. [ABSTRACT FROM AUTHOR]

In recent years, it has been found that adjusting the organizational structure of Co3O4 through solid solution and other methods can effectively improve its catalytic performance for the oxidation of low concentration methane. Its catalytic activity is close to that of metal Pd, which is expected to replace costly noble metal catalysts. Therefore, the in-depth research on the mechanism and methods of Co3O4 microstructure regulation has very important academic value and economic benefits. In this paper, we reviewed the catalytic oxidation mechanism, microstructure regulation mechanism, and methods of nano-Co3O4 on methane gas, which provides reference for the development of high-activity Co3O4-based methane combustion catalysts. Through literature investigation, it is found that the surface energy state of nano-Co3O4 can be adjusted by loading of noble metals, resulting in the reduction of Co–O bond strength, thus accelerating the formation of reactive oxygen species chemical bonds, and improving its catalytic effect. Secondly, the use of metal oxides and non-metallic oxide carriers helps to disperse and stabilize cobalt ions, improve the structural elasticity of Co3O4, and ultimately improve its catalytic performance. In addition, the performance of the catalyst can be improved by adjusting the microstructure of the composite catalyst and optimizing the preparation process. In this review, we summarize the catalytic mechanism and microstructure regulation of nano-Co3O4 and its composite catalysts (embedded with noble metals or combined with metallic and nonmetallic oxides) for methane combustion. Notably, this review delves into the substance of measures that can be used to improve the catalytic performance of Co3O4, highlighting the constructive role of components in composite catalysts that can improve the catalytic capacity of Co3O4. Firstly, the research status of Co3O4 composite catalyst is reviewed in this paper. It is hoped that relevant researchers can get inspiration from this paper and develop high-activity Co3O4-based methane combustion catalyst. [ABSTRACT FROM AUTHOR]