SCIENCE OF THE TOTAL ENVIRONMENT
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2024
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IF 8.2
Bo Zhang,Huaihao Xu,Han Zhang,Zhou Chen,Huiqun Shi,Shaohua Chen,Xiaojun Wang
Salinity is considered a major factor influencing nitrous oxide (N 2 O) emissions from biochemical treatment of high-salinity wastewater, but its mechanism has not been thoroughly investigated. In this study, we investigated the effects of salinity on N 2 O emissions under aerobic conditions. As salinity rose from 0.66 % to 3.66 %, N 2 O emission flux first increased and then decreased, while the emission factor (EF) consistently increased, likely due to significant inhibition of nitrification at 3.66 % salinity. Nitrogen‑oxygen dual isotope labeling experiments demonstrated that the dominant N 2 O production pathway shifted with salinity: from nitrifier nitrification (NN, 36.07 %–40.97 %) at low salinity (0.66 %, 1.66 %), to nitrification-coupled denitrification (NCD, 51.67 %) at 2.66 %, and to nitrifier denitrification (ND, up to 80.81 %) at the salinity of 3.66 %. From the changes in bacterial relative abundances and expressions of 4 key functional genes ( amoA , hao , nor , and nosZ ) revealed by metatranscriptomic sequencing, Nitrosomonas , unclassified Rhodospirillales , and Nitrospira were identified as key contributors to NN, NCD, and ND pathways, respectively, as salinity increased. We also found that the differential expressed genes and metabolites involved in energy metabolism, oxidative phosphorylation, and metabolism of amino acids, pyrimidines, and nucleotides may affect N-cycling bacteria, thereby influencing nitrogen conversion and salinity tolerance as well. This study sheds light on nitrification process in response to salinity stress and offers insights for mitigating greenhouse gas emissions from high-salinity wastewater treatment.
研究领域:
环境科学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jiale Zhang,Jianjun Chen,Jinyu Guo,Hao Chen,Longbo Xue,Chenyu Li
In this study, silicon nitride (Si 3 N 4 ) powders with high α-phase content and rod-like crystal morphologies were synthesized via self-propagating high-temperature synthesis (SHS) in a low-pressure nitrogen atmosphere (0.2 MPa), using silicon and Si 3 N 4 powders as reactants, with magnesium powder serving as an igniter. The influence of different ratios of silicon to silicon nitride on the phase composition, crystal morphology, and sintering activity of the synthesized Si 3 N 4 powders was systematically investigated. The results demonstrated that controlling the silicon-to-silicon nitride ratio under low-pressure conditions significantly affects the formation of α-phase Si 3 N 4 and the resulting microstructure of the powders. A low-pressure nitrogen atmosphere was adopted based on kinetic and thermodynamic analyses, providing a feasible environment for SHS. Notably, in situ formation of magnesium nitride (MgSiN 2 ) during the reaction not only acted as an effective sintering aid but also improved the thermal conductivity of the resulting Si 3 N 4 ceramic. The powder produced from a reaction using a raw material composition of 65% Si minimizes both silicon infiltration and melting to the greatest extent, and consequently, the sintered silicon nitride ceramics exhibit the highest thermal conductivity. The low-pressure environment effectively moderated the reaction rate and temperature, promoting the formation of fine α-phase Si 3 N 4 particles with rod-like morphologies. This innovative method offers a cost-effective and environmentally friendly approach for producing high-quality Si 3 N 4 powders with high sintering activity.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2024
·
IF 12.7
Shasha Wang,Yuli Wei,Rongzhe Wang,Qing Liu,Qing Wang,Shaohua Luo,Yahui Zhang,Shengxue Yan,Pengqing Hou,Xin Liu,Jing Guo,Wenning Mu
Nitrogen-doped carbon is regarded as a promising anode for potassium ion batteries (PIBs) because nitrogen atoms can regulate the structures of carbon and generate abundant active sites. How to improve the nitrogen content in carbon through simple and effective methods remains to be further addressed. In this paper, a carbon material (60NC) with ultrahigh nitrogen content (16 %) was prepared from graphite phase carbon nitride (g-C 3 N 4 ) by a convenient freeze-drying and high-temperature pyrolysis method, assisted by citric acid. When used as an anode for PIBs, 60NC exhibited a superior reversible capacity of 318.1 mAh g −1 after 200 cycles at 0.1 A g −1 . Even at the high current density of 1A g −1 , 60NC maintained a specific capacity of 261.8 mAh g −1 after 1000 cycles. The excellent electrochemical performance of 60NC mainly stems from its abundant K + storage active sites caused by nitrogen doping, large layer spacing, and hierarchical porous structure.
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Song Wu,Yongfeng Xia,Ming Zhu,Jun Zhao,Dongxu Yao,Yu-Ping Zeng
Si 3 N 4 ceramics now face new applications and challenges in the semiconductor field. The preparation of h-BN/Si 3 N 4 machinable ceramics incorporating 5–30 vol% h-BN via hot-pressing was carried out. This study systematically explored how the varying h-BN content influenced the composite's microstructure, mechanical attributes, and machinability . The results showed that some of the h-BN was encapsulated by growing Si 3 N 4 grains to form an intragranular structure during the process of hot-pressing, while the remaining h-BN exhibited uniform distribution along grain boundaries. The Si 3 N 4 phase transition in composites was inhibited by excessive h-BN, accompanied by a higher decrease in densification. The sample containing 20 vol% h-BN exhibited the best comprehensive performance, with high mechanical strength and excellent machinability. The bending strength and fracture toughness remained high at 862 MPa and 10.3 MPa m 1/2 , and could be effortlessly machined with cemented carbide drills. Additionally, the machinability of the composites was systematically characterized through observations of crack propagation paths, fitting of R-curves, and mechanical drilling tests.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
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2025
·
IF 7.9
Zeyang Chen,Xin Weng,Qibin Zeng,Yunhe Xie,Yifan Liu,Yuancai Lv,Minghua Liu
Nitrogen-doped porous carbon materials derived from agricultural waste are considered ideal for supercapacitor applications. However, current research is limited to nitrogen doping, with insufficient analysis of the effects of different nitrogen species on capacitor performance. This study compares four different nitrogen sources, revealing that the MN-AC electrode material, prepared using melamine as the nitrogen source, effectively enhances the physicochemical structure and electrochemical performance of the electrode. It exhibits the highest surface nitrogen content (4.54 %) and an optimal mesopore rate (20.6 %), with a significant amount of pyrrole nitrogen (53.19 % of the surface content), which notably improves the material's polarization and wettability, thereby enhancing its electrochemical performance. At a current density of 0.5 A g −1 , MN-AC demonstrates a high specific capacitance of 349.3 F g −1 . Furthermore, in a 6 M KOH electrolyte, it achieves an energy density of 20.3 Wh kg −1 and a power density of 169 W kg −1 . DFT analysis indicates that pyrrole nitrogen increases the material's dipole moment, enhancing the adsorption of electrolyte ions (K + ).
研究领域:
材料科学
·
能源存储
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产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Chengming Long,Sirui Liu,Di Wang,Zhaoqi Lu,Qiulan Zhang,Qiong Gao,Mingyi Zhang,Xinzhi Ma
Photoelectrochemical hydrogen production technology holds promise for directly and swiftly generating green hydrogen, which is pivotal for human welfare; however, it faces challenges posed by the energetically sluggish oxygen evolution reaction (OER). Cobalt-based nitrides are considered excellent photoelectrochemically active in the OER (PEOER) catalysts, and their conductivity and photoconversion efficiency remain relatively low. This paper presents the fabrication of Ni-alloyed Co4N nanowire arrays on carbon cloth ((Co1–xNix)4N NWAs/CC) as PEOER catalysts. By analyzing advanced in situ Raman and X-ray photoelectron spectroscopy (XPS) results, we discovered that Ni not only enhances the conductivity of the catalyst but, more importantly, also creates more photoexcited Co2+ OER centers and favors its reconstruction to CoOOH to charge PEOER. Furthermore, nitrogen plays a critical role in transforming pyridinic nitrogen into other forms of nitrogen to stabilize the catalyst’s structure. These advantages endow (Co0.74Ni0.26)4N NWAs/CC with remarkable PEOER enhancement (988%), which drives the standard current density of 10 mA cm–2 with only a 283 mV overpotential along with good durability. This research provides insights into the PEOER mechanisms of cobalt-based transition metal nitrides, providing a way for designing next-generation PEOER catalysts.
研究领域:
材料科学
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催化化学
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可再生能源
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产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2024
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IF 8
Ruilong Ma,Wenchao Gan,Yuanhu Zeng,Shuanglong Feng,Shukai Duan,Peter Feng,Xiaoyan Peng
The demand for gas sensors is experiencing rapid growth, driven by the increasing need for air quality detection in the face of environmental pollution and industrial emissions. However, the widely used metal oxide semiconductor (MOS) gas sensors suffer from drawbacks such as low ability to predict gas concentration and poor selectivity . In this work, a sensor array was fabricated consisting of 10 various gas sensors and combined with an advanced deep learning algorithm to achieve precise predictions of nitrogen dioxide (NO 2 ) at low concentrations. First, graphitic carbon nitride (g-C 3 N 4 ) and In 2 O 3 nanoparticles were composited with different mass ratios, resulting in the formation of distinct g-C 3 N 4 /In 2 O 3 composites as sensing materials. Afterward, SEM, TEM , and XRD were employed to characterize the morphology, structure, and elemental composition of the samples. Furthermore, sensing properties including response, selectivity , and repeatability, are studied for 10 gas sensors based on g-C 3 N 4 /In 2 O 3 composites. Finally, the convolutional neural network-efficient channel attention-gate recursive unit (CNN-AGRU) model was proposed to analyze the patterns of the signals collected from the sensor array when exposed to various NO 2 concentrations from 1 to 9 ppm. The results demonstrated the integration of high-selectivity sensing materials to NO 2 and an advanced deep learning algorithm CNN-AGRU enables to realize a high concentration prediction accuracy of about 97.04% and a low prediction error of 0.20527 ppm for NO 2 gas.
研究领域:
材料科学
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环境科学
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人工智能
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产品关联
DOI
高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 7
·075314
·
IF 1.449
Lu Chen,Chao Xiao,Yunlu Tang,Xian Zhang,Kang Zheng,Xingyou Tian
A multilayered thermally conductive composite with ternary system of heat conductive fillers-thermally conductive films-epoxy matrix was prepared through a facile process of layer-by-layer stacking, pre-curing and hot-pressing. The thermally conductive films (boron nitride nanosheets/cellulose nanofiber) with high in-plane thermal conductivities were employed as the heat conductive medium, while the platelet-shaped hexagonal boron nitride and the particle-shaped aluminum nitride were utilized as heat conductive fillers for enhancing the perfection of the thermally conductive network. A horizontally heat conductive network was constructed within the epoxy matrix under the joint contribution of the horizontally aligned hexagonal boron nitride platelets and the parallelly spread thermally conductive films through hot-pressing. The aluminum nitride particles acted as linking points, filling the gaps between hexagonal boron nitride platelets, while constructing the thermally conductive path in the vertical direction. Thanks to the introduction of thermally conductive films and the good orientation of boron nitride platelets, the in-plane thermal conductivities of the composites increased with increasing of film layer number. With film layer number of 9, and filler content of 30 wt% (aluminum nitride/boron nitride (1:1)), the in-plane thermal conductivity of the composite was as high as 8.53 W m−1 * K, which showed an enhancement of 4165% than that of the pure epoxy matrix, and an improvement of 613% compared to that of the composite without multilayered structure. Meanwhile, the out-of-plane thermal conductivity exhibited a slightly deceased tendency as film layer number increased, but it still reached 0.87 W m−1 * K with film layer number of 9, which was 335% higher than that of the pure epoxy. In addition, the multilayered composite also possessed good thermal stability, enhanced stiffness, as well as low dielectric constant and dielectric loss, which shows a potential application in thermal management for packaging of integrated circuit and microelectronic devices.
研究领域:
材料科学
·
热管理技术
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Shuyan Yin,Yi-Xuan Wang,Cheng Hou,Jing Wang,Jing Xu,Xinbai Jiang,Dan Chen,Yang Mu,Jinyou Shen
Anammox coupled partial S 0 -driven autotrophic denitrification (PS 0 AD) technology represents an innovative approach for removing nitrogen from wastewater. The research highlighted the crucial role of biofilm on sulfur particles in the nitrogen removal process. Further analysis revealed that sulfur-oxidizing bacteria (SOB) are primarily distributed in the inner layer of the biofilm, while anammox bacteria (AnAOB) are relatively evenly distributed in inner and outer layers, with Thiobacillus and Candidatus Brocadia being the dominant species, respectively. Except for anammox and PS 0 AD processes, 15 N isotope labeling tests determined that sulfur reshaped nitrogen metabolism pathways, providing solid evidence for the occurrence of sulfammox process. SOB and AnAOB collaborate in nitrogen and sulfur conversion, with SOB-drived PS 0 AD processes reducing nitrate to nitrite for AnAOB to remove ammonia. Conversely, the nitrate produced from anammox process can be reused by SOB. Metagenomic analyses verified that SOB drove the PS 0 AD process through encoding soxBYZ gene, while AnAOB might play an important role in simultaneously driving the anammox and sulfammox processes. These findings underscore the importance of biofilm and clarify the nitrogen-sulfur cycle mechanisms within the coupled system.
研究领域:
环境微生物学
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废水处理工程
·
分子生态学
✓ 已验证
DOI
高影响因子
CARBON
·
2018
·
IF 7.082
Xiujun Qi,Kangsheng Huang,Xuan Wu,Wei Zhao,Hong Wang,Quanchao Zhuang,Zhicheng Ju
Potassium-ion batteries (PIBs) are an emerging energy storage technology for low cost and large scale applications. However, due to the larger K ions it suffers insufficient cycle life and poor rate capability. In this paper, these problems are surmounted by using N-doped porous carbon (NPC) anodes. Excellent electrochemical performance was demonstrated with a high reversible capacity of 296.8 mA h g −1 after 100 cycles at a current density of 50 mA g −1 . The superior performance is mainly ascribed to well-defined pore structure and high nitrogen content. The unique porous structure can effectively alleviate the volume expansion induced by the insertion of large K ions. Moreover, nitrogen doping can generate different types of defects and vacancies, thereby providing more electroactive sites. Given the abundance and universal distribution of potassium in the Earth's crust, the encouraging results make NPC a promising candidate for KIBs anodes.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Kezhuo Li,Jin Luo,Longhao Dong,Gaoqian Yuan,Wen Lei,Quanli Jia,Haijun Zhang,Shaowei Zhang
Porous ceramics have attracted extensive attention because of their high porosity, low thermal conductivity , large specific surface area and good corrosion resistance . In this work, TiN porous ceramics with high porosity are successfully prepared via the combination of freeze-drying and in-situ nitridation reaction method using Ti powder and chitosan as raw materials. The influence of the solid content of Ti powder, the concentration of chitosan/acetic acid solution and the nitridation temperature on the morphologies and physical properties of as-prepared TiN porous ceramics are fully investigated. The sample with high porosity of 92.8% and low bulk density of 0.27 g/cm 3 can be obtained through optimal parameters (the solid content of Ti powder is 9.6 wt%, the concentration of chitosan/acetic acid solution is 5 wt%, and the nitridation temperature is 1473 K). Particular emphasize is that the as-prepared TiN porous ceramics can be used as sulfur host material for lithium-sulfur batteries (LSBs). Good rate performance and cycle stability of TiN/S electrodes are achieved by electrochemical performance tests. The initial discharge capacity of TiN/S electrodes is 778 mAh g −1 at 0.5C, and the capacity retention rate is 94% after 200 cycles.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 46
·18008-18014
·
IF 8.262
Hongli An,Ruikang Zhang,Zhenhua Li,Lei Zhou,Mingfei Shao,Min Wei
Nitrogen-doped carbon nanotubes (NCNTs) are recognized as one of the most promising oxygen reduction reaction (ORR) catalysts, while developing a preparation protocol for CNT-based ORR catalysts with cost-effective synthesis, high activity and durability is still a challenge. In this work, we report the fabrication of N-doped CNT catalysts with a homogeneous distribution of dopants in the CNT matrix by pyrolysis of a core–shell nanostructured CNTs@polypyrrole nanocomposite (CNTs@PPy). The as-obtained NCNTs exhibit excellent performance in electrocatalytic oxygen reduction with an onset potential of 0.95 V vs. RHE, a diffusion-limited current of 6.82 mA cm−2 and excellent stability in alkaline media, much superior to that of reported CNT-based ORR catalysts as well as commercial Pt/C. Moreover, the ratio of different nitrogens (pyridinic, pyrrolic and graphitic N) can be tuned easily by changing the coating amount of PPy in the CNTs@PPy core–shell precursors; and the results indicate that the pyridinic-N in the CNTs@PPy derived NCNTs plays a key role in promoting the ORR performances.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）