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Because of the excessive carbon dioxide emissions, the greenhouse environmental problem has become a widely research hot. Porous carbon with plentiful of 3D porous stricture and excellent electrochemical performance has attracted more and more attention. The topic about the porous carbon for CO2 adsorption has been reported, hence, in the paper, we adopted the carboxymethyl chitosan as the porous carbon precursor, and copper sulfate as the metal source, KOH and KCl as the pore forming materials. In the preparation process, the high temperature carbonization and low temperature air-activation are used to improve the porous structure. The obtained material exhibited a high surface area and a defective structure. The value of SSA is up to 1018 m2 g-1, the micropore SSA is up to 807 m2 g-1, whcih is good for CO2 adsorption. This work can provide a helpful method for porous carbon preparation.

BACKGROUND: Bacterial cellulose (BC) is a fiber substance produced by microbial fermentation. It is widely used in the food preservation industry because of its extremely pure texture, high crystallinity and high biocompatibility. In the present study, bacterial cellulose/thyme essential oil (BC/TEO‐E) with antibacterial and fresh‐keeping functions was prepared by ultrasonic treatment of modified bacterial cellulose for encapsulation of thyme essential oil, which effectively inhibited the spoilage of chilled chicken. RESULTS: The purified BC, produced by Acetobacter xylinum ATCC 53524, was ultrasonically treated wih different times (0, 30, 60 and 90 min). Transmission electron microscopy, scanning electron microscopy, Fourier transformed infrared spectroscopy, X‐ray diffraction, differential scanning calorimetry and zeta potential were used to characterize the structure of BC after ultrasound, showing that BC, treated for 30 min, had the optimal fiber structure, crystallinity (85.8%), thermal stability (347.77 °C) and solution stability (−26.63 ± 1.96 mV). BC/TEO‐E was prepared by a homogenizer for the preservation of chilled chicken. Optical microscopy indicated that the BC/TEO‐E prepared by 0.5% BC had optimal dispersion and stability, and even no delamination was observed in the emulsion. Compared with other groups (control, 0.5% BC and Tween‐E), the total number of colonies and coliforms in chilled chicken treated with 0.5% BC/TEO‐E was the lowest during the whole storage period (12 days), indicating that it can effectively inhibit bacterial growth. In addition, total volatile base nitrogen (TVB‐N), thiobarbituric acid reactive substances, pH and drip loss results showed that 0.5% BC/TEO‐E could effectively inhibit the spoilage of chilled chicken compared to the other treatment groups. CONCLUSION: All of the results acquired in the present study indicate that BC/TEO‐E has a potential application in chilled chicken preservation. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Due to high specific surface and plentiful of porosity, 3D porous carbon matrix has shown enormous potential for catalyst supporters. Hydrogen was thought as the next-generation clean energy to substitute the fossil fuel. Metal phosphides has been investigated and exhibited a good catalytic performance for hydrogen evolution reaction (HER). In this work, we prepared Ni2P/CoP loading on Porous carbon matrix through a facile method. The mixture of nickel nitrate, cobalt nitrate and chitosan was ball-milled, then was carbonized under N2 atmosphere at 900°C with NH4HPO2. The as-obtained materials were characterized by X-Ray diffraction (XRD), SEM and Raman spectrums. Also the electrochemical performance for HER was test using electrochemical workstation. The result shown that this catalysts presented a low overpotential at 10 mA cm-2, which was 270 mV.

Multifunctional electrocatalysts are desirable for overall water splitting and zinc-air batteries. In this work, N, S co-doped carbon nanotubes (CNT-NS) with a plentiful of defects were obtained through a novel molecular-level codoped and lattice defect construction method. Thiamine hydrochloride and thiocarbamide were adopted as new precursors in situ doping N and S into multi-walled CNTs surfaces, and lattice defects were constructed by in situ chemical etching using ammonium chloride and ammonium bicarbonate. These surface defects and N,S biatom co-doping synergistic effects can accumulate the CNT-NS to exhibit the superior behavior for electrocatalysis of water splitting and zinc-air batteries. The overpotential for overall water splitting was 1.61 V and the specific capacity for zinc-air batteries was 781 mA h g−1, which was superior to previous works. According to the Operando Raman spectroscopy measurements, the S atoms can serve as the intrinsic catalytic sites for HER and OER, and the defective CNT structures could enhance the catalytic kinetics by the electron-transfer process. Further, density functional theory (DFT) results also indicated the contribution of binary atoms co-doping for low ΔG H∗ values. Therefore, this work provides the valuable reference for rational design/construction for metal-free catalysts of overall water splitting. [Display omitted] • CNT-550-NS were successfully prepared through a molecular-level codoped and lattice defect construction method. • CNT-550-NS exhibited a plentiful of defective structure on the carbon nanotubes surfaces. • CNT-550-NS possessed a high contents of heteroatoms of N and S. • CNT-550-NS executed a remarkable performance for HER, OER and ORR. [ABSTRACT FROM AUTHOR]

Nitrogen-enriched graphene-like carbon materials were successfully prepared via pyrolysis of a mixture of melamine, ammonia chloride (NH4Cl) and polyvinyl pyrrolidone (PVP) at a mild temperature without inert gas protection. Different techniques were used to analyze the physical and chemical properties of the products. All the prepared materials showed excellent performance in methylene blue (MB) adsorption, In particular, the materials prepared with 3 g polyvinyl pyrrolidone (PVP) (NCG-2) exhibited the best performance, a very high maximum adsorption capacity of 348.2 mg/g, much larger than many reported materials. The high adsorption capacity of the Nitrogen-doped graphene-like carbon materials was possible due to its uniform porous structure, high specific surface area. Moreover, NCG-2 could be recycled and only a only slightly decreased in the removal efficiency were observed after 5 cycles.