Search

Rational design and synthesis of bifunctional oxygen electrocatalysts with high activity and stability are key challenges in the development of rechargeable Zn-air batteries (ZABs). In this paper, tungsten carbide (WC) and Co7Fe3 embedded in N,P co-doped hierarchical carbon (WC/Co7Fe3-NPHC) was prepared by using zeolite imidazolate frameworks as precursor. Density functional theory demonstrates that the mutual adjustment among the WC, Co7Fe3, and N,P co-doped carbon at the three-phase heterojunction interface makes the catalyst possess moderate adsorption strength, and greatly improves the conductivity and electron transfer rate of the catalyst. As a result, the WC/Co7Fe3-NPHC exhibits a low overall oxygen redox potential difference of 0.72 V, while the ZAB assembled by WC/Co7Fe3-NPHC as an air cathode exhibits ultra-long cycle stability of over 550 h. Futhermore, WC/Co7Fe3-NPHC can keep good charge and discharge stability at different bending angles when applied to flexible solid ZAB. [ABSTRACT FROM AUTHOR]

Developing low‐cost, efficient, and stable trifunctional electrocatalyst for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) is still a significant challenge. Herein, this study reports a zeolitic imidazolate framework (ZIF) derived trifunctional electrocatalyst, composed of Co5.47N and Co7Fe3 (CoFeN) that embedded into 1D N‐doped carbon nanotubes modified 3D cruciform carbon matrix (NCNTs//CCM). Benefiting from the robust interfacial conjugation of Co5.47N/Co7Fe3 and the 1D/3D hierarchical structure with a large surface area, the as‐prepared CoFeN‐NCNTs//CCM display trifunctional electrocatalytic activity for ORR (half‐wave potential of 0.84 V), OER (320 mV at 10 mA cm–2), and HER (−151 mV at 10 mA cm–2). The assembled Zn‐air battery exhibits high power density (145 mW cm–2), enhanced charge–discharge performance (voltage gap of 0.76 V at 10 mA cm–2), and long‐term cycling stability (over 445 h). The resultant overall water‐splitting cell achieves a current density of 10 mA cm–2 at 1.63 V, which can compete with the best reported trifunctional catalysts. What is more, the self‐assembled Zn‐air batteries are utilized to power the overall water splitting successfully, verifying great potential of the CoFeN‐NCNTs//CCM as functional material for sustainable energy storage and conversion system. [ABSTRACT FROM AUTHOR]

BACKGROUND Selective absorption of oils by macroporous solid absorbents has been regarded as an easy, environment-friendly and economical way to gather oils for oil-water separation, oil contamination cleanup and easy transport/storage. Cheap absorbent material with high oil-absorption performance is a key factor to promote its large-scale application. RESULTS Highly oil-absorptive and water-repellent carbonized asphalt-melamine sponges ( AMS) have been prepared via a dip-coated sponge carbonization process, using deoiled asphalt ( DOA) as dip-coating reagent and melamine sponge ( MS) as template. By the combination of DOA-derived surface modification and mild carbonization at 600°C, the AMS products obtained such key properties as low density, highly selective absorption of oils against water, flexibility, good fire-resistance and thermal stability, and good recyclability. CONCLUSION These findings indicate that AMS can be a promising oil-absorbent material applicable to oil pollution control on a water surface. Benefiting from both cheap raw materials and facile economical manufacturing process, the approach proposed can contribute to the mass manufacturing of cheap oil-absorbent products with high oil-absorption performance. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Fe–C alloy filler was prepared using iron powder and activated carbon. And it was proved to be efficient in getting rid of chloride from water, especially saline wastewater. Generally, biochemical treatment efficiency will be low if the concentration of chloride ion (Cl−) in water reaches 10,000 mg/L. Once the Cl−content exceeds 20,000 mg/L, most microbes will lose activity because of the high osmotic pressure. Besides, it will not only affect the microbes’ survival but also be toxic to the microorganisms. This paper studied chloride removal efficiency with iron-carbon alloy. Factors affecting the removal efficiency and the possible removal mechanism were also investigated. Treatment effect for actual salinity wastewater with the filler was reported. The results showed that the new filler could effectively remove chloride ions and chemical oxygen demand (COD). CODCrremoval rate of the chosen practical wastewater samples was higher than 55%, and the Cl−removal rates were 27%, 30% and 25%, respectively. The oxygen consumption curves of the wastewater that were obtained from chemical industries showed that the biodegradability of wastewater could be greatly improved due to removal of Cl−using the new filler. [ABSTRACT FROM PUBLISHER]

Directionally induced interstitial Ru dopant rather than ordinary substitutional doping is a challenge. Furthermore, DFT calculations revealed that compared with the substituted Ru dopants, the interstitial Ru dopants induce abundant Ni(Fe)Ru cooperative sites, greatly expediting the reaction kinetics for HER and OER. Inspired by these, the interstitial Ru-doped NiFeP/NF electrode is constructed by the 'quenching doped Ru-phosphorization' strategy. Relevant physical characterizations confirmed that interstitial Ru dopants promote electron reset in the Ni(Fe)Ru synergistic sites, effectively avoiding metal atom dissolution and encouraging more Ni (Fe)OOH active species. As expected, the Ru-NiFeP/NF||Ru-NiFeP/NF electrolyzer only need as low as 1.54 V to yield a current density of 1 A cm -2 . In summary, this work innovatively constructs the phosphide electrode with ampere-level current density from the perspective of regulating the doping position of Ru. This provides a new design idea for optimizing the Ru doping strategy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objectives: This study investigated and analyzed the association of interferon-γ (IFN-γ) gene polymorphisms and Th1/Th2 balance in tuberculosis susceptibility., Methods: From January 2018 to January 2020, 121 tuberculosis patients that were hospitalized for initial treatment and were chosen as the pulmonary tuberculosis group, and another 80 healthy individuals with physical examination in the same period were selected as the control group. The genetic distribution of IFN-γ +874 sites in the two sets of subjects was detected by sequence-specific primer PCR (PCR-SSP), the serum IFN-γ level was detected by ELISA, and the ratio of Th1 and Th2 on cells in two sets of subjects were detected by flow cytometry. Subsequently, we compared the differences in IFN-γ degree and the changes in Th1/Th2 in patients with different genotypes., Results: The difference in the distribution of IFN-γ (+874 T/A) genotype frequencies between the two groups of subjects was significantly different ( P<0.05 ), and the frequency of A allele in the tuberculosis group was clearly higher than that in the control group ( P<0.05 ). Compared with the control group, the Th1 cells percentage in the pulmonary tuberculosis group decreased remarkably, the Th2 cells percentage increased significantly, while the Th1/Th2 ratio was notably decreased ( P<0.05 ). In addition, the Th1/Th2 ratio in tuberculosis patients with an IFN-γ (+874 T/A) genotype AA was remarkably lower than those with AT+TT genotype ( P<0.05 )., Conclusion: An AA genotype with IFN-γ (+874 T/A) is a susceptible genotype for tuberculosis. The mechanism may be related to the imbalance of Th1/Th2 which is more likely to occur in patients with AA genotype. This can lead to a decline in immune function of the body, making it more susceptible to infection with mycobacterium which induces tuberculosis., Competing Interests: None., (AJTR Copyright © 2021.)

Slow-release organic carbon-source (SOC) material, a new kind of electron donor for in situ groundwater denitrification, was prepared and evaluated in this study. With starch as a biologically utilized carbon source and polyvinyl alcohol (PVA) as a frame, this material performed controllable carbon release rates and demonstrated stable behaviour during the simulated denitrification process. Raman spectrum analysis showed that the PVA skeleton formed cross-linking network structures for hydrogen-bonded water molecules reset in low temperatures, and the starchy molecules filled in the interspace of the skeleton to form a two-phase interlocking/disperse phase structure. In a static system, carbon release processes followed the Fickian law with (1.294-6.560)×10(-3) mg g(-1) s(-1/2) as the release coefficient. Under domestication and in situ groundwater simulation conditions, SOC material played a favourable role during denitrification, with 1.049±0.165 as an average carbon-nitrogen ratio. The denitrification process followed the law of zero-order kinetics, while the dynamics parameter kN was 0.563-8.753 gN m(-3) d(-1). Generally, SOC material was suggested to be a potential carbon source (electron donor) suitable for in situ groundwater denitrification.

Based on the theories of organic polymer and chemical kinetics, the structure and mass transportation model of slow-release organic carbon-source (SOC) material was developed in this study to reveal and predict the carbon release mechanisms of polymer carbon source, which was feasible for in situ denitrification in nitrate-contaminated groundwater. Composed of polyvinyl alcohol (PVA) and starch, the SOC material formed the interlocking/disperse-phase structure. PVA performed as continuous phase and skeleton, whereas the starch or cellulose behaved as release component. Carbon release process was identified in two stages: solid-phase (inner) and interface (gel layer) diffusion. Solid-phase diffusion was affected by material porous medium parameters, for example, distance between the crosslinking points and starch free energy. The interface diffusion depended mostly on the groundwater dynamics and interface energy distribution. The interface diffusion was found as the limiting step of carbon release process, and the carbon release coefficient corresponded to kD,I as static coefficient and kC,I as dynamic coefficient. As the key indicator to evaluate carbon release capacity, kD,I and kC,I represented appropriate boundary conditions and interface properties. Sensitivity analysis showed that the key parameters of the carbon release model were the distance between the crosslinking points and the free energy of polymer, influenced by regulation of preparation technique, raw material composition and additive dosage.