摘要:
N-doped porous carbons of C(N)-n were prepared for remarkable rate capacitive properties and excellent CO2 capture performance using Chitosan as both carbon and nitrogen sources. At the edge of amorphous C(N)-n materials, a part of atoms are arranged ordered on account of the graphitization. Besides, the optimal ID/IG ratio is 1.02. In the optimized sample of C(N)-700, N element exists in the framework as pyridinic N, pyrrodic N, quaternary N, oxidized N and the proportion is 7.3%. Moreover, the specific surface area and pore volume reach 243 m2/g and 0.633 cm3/g, respectively. In 6 M KOH, the C(N)-700 material generates a pseudocapacitance along with the double-layer capacitance (EDLC). When the current density is 0.2 A/g, the discharge capacity and energy density are 502 F/g and 6.5 Wh/kg, respectively. Compared with the discharge capacity at 0.2 A/g, it still keeps 61.7% at 40 A/g. The superior electrochemical performance has a closely connection with the huge pore volume, surface area and the doping of N species, which afford rapid ions migration, abundant residence sites and outstanding pseudocapacitance properties. CO2 capture behavior on the N-doped carbons complie with Bangham mode. When the system temperature is 25 degrees C, the C(N)-700 material achieves an appreciable capture amount of 4.25 mmol/g in a stream of 40 mL/min. At room temperature, the adsorption capacity ratios of CO2/ N2 and CO2/O2 are 2.6 and 3.7, respectively. The superior CO2 adsorption performance is also closely in connection with the unique pore structure and plentiful N affinity places.
摘要:
随着专业认证和“双碳”战略的推进,化工领域对于可持续发展的要求越来越高。在此背景下,本校的《化工热力学》教学改革从理论教学和实验教学两方面出发,采取案例教学、创新实验、多元评价等举措,将理论知识与工程实践紧密结合,以此培...展开更多 随着专业认证和“双碳”战略的推进,化工领域对于可持续发展的要求越来越高。在此背景下,本校的《化工热力学》教学改革从理论教学和实验教学两方面出发,采取案例教学、创新实验、多元评价等举措,将理论知识与工程实践紧密结合,以此培养学生的绿色发展意识和创新能力,提升专业素养、实际操作和解决复杂问题的能力,从而为“双碳”战略的实施提供人才支持,为培养适应未来化工行业发展需求的优秀人才作出贡献。With the advancement of professional certifications and the implementation of the “dual carbon” strategy, the chemical industry is placing increasing demands on sustainable development. Under the background, our school’s reform in teaching “Chemical Thermodynamics” focuses on both theoretical and experimental teaching. It incorporates case studies, innovative experiments, and diverse assessments, closely linking theoretical knowledge with engineering practice. This approach aims to cultivate students’ awareness of green development and innovation capabilities, and enhance their professional competence, practical skills, and problem-solving abilities. Ultimately, it aims to support the implementation of the “dual carbon” strategy by nurturing talent and contributing to the development of excellent professionals who can meet the future needs of the chemical industry.收起
摘要:
The construction of robust electrodes with promoted kinetics of sulfur redox reactions and enduring redox chemistry is crucial for developing advanced Li-S batteries. Herein, a hybrid sulfur cathode based on CuBr quantum dots (QDs)-interspersed reduced graphene oxide (rGO) is first developed for energy-dense Li-S batteries. With the combination of theoretical calculations and experimental results, it is certified that the CuBr QDs anchored on the rGO surface could efficiently improve the chemical adsorption and transformation of sulfur-related species, which significantly facilitates desired redox reaction, thus resulting in a durable and fast long-term cycling performance. Under practically-relevant conditions, the assembled pouch cell could deliver a high initial gravimetric energy density of 375 Wh kg−1 with decent durability, showing great application prospects in lean-electrolyte Li-S batteries.
The construction of robust electrodes with promoted kinetics of sulfur redox reactions and enduring redox chemistry is crucial for developing advanced Li-S batteries. Herein, a hybrid sulfur cathode based on CuBr quantum dots (QDs)-interspersed reduced graphene oxide (rGO) is first developed for energy-dense Li-S batteries. With the combination of theoretical calculations and experimental results, it is certified that the CuBr QDs anchored on the rGO surface could efficiently improve the chemical adsorption and transformation of sulfur-related species, which significantly facilitates desired redox reaction, thus resulting in a durable and fast long-term cycling performance. Under practically-relevant conditions, the assembled pouch cell could deliver a high initial gravimetric energy density of 375 Wh kg−1 with decent durability, showing great application prospects in lean-electrolyte Li-S batteries.
作者机构:
[Zhou, Wang; Mo, Ying; Gao, Peng; Ke, Jinlong; Liu, Jilei] College of Materials Science and Engineering, Hunan Joint International Laboratory of Advanced Materials and Technology of Clean Energy, Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, Hunan University, Changsha, 410082 China;[Wang, Kexuan; Chen, Shi] Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Macau, 999078 China;[Liu, Zheng] College of Materials and Chemical Engineering, Key Laboratory of Low Carbon and Environmental Functional Materials of College of Hunan province, Hunan City University, Yiyang, 413000 China
通讯机构:
[Jilei Liu] C;College of Materials Science and Engineering, Hunan Joint International Laboratory of Advanced Materials and Technology of Clean Energy, Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, Hunan University, Changsha, 410082 China
关键词:
charge transfer;extreme fast charging;graphite anode;potassium ions batteries;solid electrolyte interphase
摘要:
<jats:title>Abstract</jats:title><jats:p>Improving interfacial kinetics is the key to realizing extreme fast charging (XFC) of graphite‐based potassium ion batteries (PIBs). The electrolyte engineering is commonly used for solid electrolyte interphase (SEI) design. However, this strategy adjusts both ion solvation structure and (de)solvation kinetics simultaneously, thus making it difficult to explicitly reveal the linkage between SEI properties and interfacial kinetics. Herein, the content of inorganic species in preformed SEI on graphite surface is precisely regulated and uncovered its critical role in improving the interfacial kinetics. The charge transfer kinetics on graphite/electrolyte interphase is found to be the rate limitation step upon XFC. Meanwhile, the increased inorganic species in SEI plays a decisive role in optimizing the charge transfer rather than the kinetics of naked K<jats:sup>+</jats:sup> crossing SEI. Through unlocking the anodic charge transfer limitation with ultra‐inorganic rich SEI, the graphite//Prussian blue analogs full cells achieve a superior XFC ability (13min charge to 80%) with a specific capacity of 103mAhg<jats:sup>−1</jats:sup> at 5C. This work provides a fundamental understanding of the relationship between SEI properties and interfacial kinetics during XFC, which enables the rational design of SEI chemistry for fast‐charging PIBs.</jats:p>
作者机构:
[Liu, Bangfu; Liu, BF] Hunan Elect Informat Ind Inst, Jiefangdonglu 51, Changsha 410000, Hunan, Peoples R China.;[Zhou, Le-zhou] Hunan Prevent & Treatment Inst Occupat Dis, Changsha 410007, Hunan, Peoples R China.;[He, Guo-wen] Hunan City Univ, Coll Mat & Chem Engn, Yiyang 413000, Hunan, Peoples R China.;[Wang, Chaoli] Air Force Mil Med Univ, Dept Pharm, Xian 710000, Shanxii, Peoples R China.
通讯机构:
[Liu, BF ] H;Hunan Elect Informat Ind Inst, Jiefangdonglu 51, Changsha 410000, Hunan, Peoples R China.
关键词:
Hydrophobic deep eutectic solvents;Stripping back extraction;Complexation;Metal ions;Three-phase separation
摘要:
In this paper, a green hydrophobic deep eutectic solvent (HDES) composed of menthol and hexanoic acid was employed to dissolve cosmetics containing Cd2+ and Cd2+ was extracted using an EDTA-2Na saturated solution, analyzed by FAAS. The study found that HDES-1 can be recycled and reused well; the stability constants of Cd2+ EDTA chelates play an important role in the extracting process; the optimum conditions were: the solubility of HDES-1 was 20 mL/g for cosmetic sample at an indoor temperature of around 10 degrees C; the dissolver-extractant ratio was 2:1; the LOD was 0.037 mg/kg; the RSD was 3.5%; and the recovery was 85.5-118.3%. The developed method was successfully applied to actual cosmetic samples with satisfactory results, and it was also applied for the determination of Mg2+, Mn2+, and Cu2+ in cosmetic samples.
摘要:
Classifying big data in hyperspectral imaging (HSI) can be challenging when minor (low-concentrated) compounds are present in actual samples, as for chemical additives and adulterants in food matrix. Herein, we propose a new strategy to classify HSI data for the identification of adulterants in food material for the first time. This strategy is based on the selection of essential spectral pixels of full HSI data followed by the feature space construction using uniform manifold approximation and projection as well as the data clustering utilizing hierarchical clustering analysis on the reduced data (named ESPs-UMAP-HCA). We apply our approach to analyze two real NIR datasets and four new Raman datasets. Compared with non-ESPs UMAP-HCA and t-distributed stochastic neighbor embedding combined with ESPs and HCA (ESPs-t-SNE-HCA), the developed strategy provides well-separated clusters for major and minor compounds in food matrix. Finally, the adulterants as minor compounds are accurately identified, which is confirmed by the fact that the extracted spectra of them perfectly match with their pure spectra. In addition, their locations are found in the contribution map even though they are present in a few pixels. What's more, the proposed strategy does not need any a priori knowledge of the data structure and the class memberships and therefore reduced the studied difficulty and confirmation bias in the analysis of big HSI datasets. Overall, the proposed ESPs-UMAP-HCA method could be a potential approach for food adulteration detection.
摘要:
This study utilized X-diffraction, BET, photoluminescence, UV–vis DRS, FTIR, SEM, XPS, TOC analysis, EPR, electrochemical measurements, and LC-MS to characterize the structural characteristics, morphology, optical properties, photocatalytic activity, surface electronic states, active compounds, and potential photodegradation pathways of rhodamine B (RhB) over as-prepared Bi2O3. The as-prepared Bi2O3 photocatalyst exhibited a narrow bandgap, which enabled efficient absorption of visible light, thereby contributing to its enhanced photocatalytic activity. Additionally, Bi2O3 exhibited a high degradation efficiency for RhB. with up to 96.8 % of RhB removed within 120 min at pH 3.0. The excellent photocatalytic performance of Bi2O3 can be attributed to the formation of the heterogeneous Bi2O3/BiOCl structure on the Bi2O3 surface in the presence of HCl. Moreover, the TOC analysis revealed that over 58.1 % of the carbon in the RhB solution was mineralized into CO2 after 120 min of irradiation. The effect of catalyst content, RhB concentration, initial pH, and inorganic anions on the photocatalytic degradation of RhB over Bi2O3 was examined. Furthermore, the active compounds and potential photocatalytic mechanism of the Bi2O3/BiOCl heterogeneous structure toward RhB were evaluated. The intermediates formed during RhB degradation were identified, and the corresponding degradation pathway was deduced via LC-MS.
This study utilized X-diffraction, BET, photoluminescence, UV–vis DRS, FTIR, SEM, XPS, TOC analysis, EPR, electrochemical measurements, and LC-MS to characterize the structural characteristics, morphology, optical properties, photocatalytic activity, surface electronic states, active compounds, and potential photodegradation pathways of rhodamine B (RhB) over as-prepared Bi2O3. The as-prepared Bi2O3 photocatalyst exhibited a narrow bandgap, which enabled efficient absorption of visible light, thereby contributing to its enhanced photocatalytic activity. Additionally, Bi2O3 exhibited a high degradation efficiency for RhB. with up to 96.8 % of RhB removed within 120 min at pH 3.0. The excellent photocatalytic performance of Bi2O3 can be attributed to the formation of the heterogeneous Bi2O3/BiOCl structure on the Bi2O3 surface in the presence of HCl. Moreover, the TOC analysis revealed that over 58.1 % of the carbon in the RhB solution was mineralized into CO2 after 120 min of irradiation. The effect of catalyst content, RhB concentration, initial pH, and inorganic anions on the photocatalytic degradation of RhB over Bi2O3 was examined. Furthermore, the active compounds and potential photocatalytic mechanism of the Bi2O3/BiOCl heterogeneous structure toward RhB were evaluated. The intermediates formed during RhB degradation were identified, and the corresponding degradation pathway was deduced via LC-MS.
摘要:
Aqueous Zn–S batteries (AZSBs) have garnered increasing attention in the energy storage field owing to their high capacity, energy density, and cost effectiveness. Nevertheless, sulfur (S) cathodes face challenges, primarily stemming from sluggish reaction kinetics and the formation of an irreversible byproduct (SO42−) during the charge, hindering the progress of AZSBs. Herein, Te–S bonds within S-based cathodes were introduced to enhance electron and ion transport and facilitate the conversion reaction from zinc sulfide (ZnS) to S. This was achieved by constructing heteroatomic TeS-x@Ketjen black composite cathodes (HM-TeS-x@KB, where x = 36, 9, and 4). The HM-TeS-9@KB electrode exhibits long-term cycling stability, maintaining a capacity decay rate of 0.1 % per cycle over 450 cycles at a current density of 10 A g−1. Crucially, through a combination of experimental data analysis and theoretical calculations, the impact mechanism of Te on the charge and discharge of S active materials within the HM-TeS-9@KB cathode in AZSBs was investigated. The presence of Te–S bonds boost the intrinsic conductivity and wettability of the HM-TeS-9@KB cathode. Furthermore, during the charge, the interaction of preferentially oxidized Te with S atoms within ZnS promotes the oxidation reaction from ZnS to S and suppresses the irreversible side reaction between ZnS and H2O. These findings indicate that the heteroatomization of chalcogen S molecules represents a promising approach for enhancing the electrochemical performance of S cathodes in AZSBs.
Aqueous Zn–S batteries (AZSBs) have garnered increasing attention in the energy storage field owing to their high capacity, energy density, and cost effectiveness. Nevertheless, sulfur (S) cathodes face challenges, primarily stemming from sluggish reaction kinetics and the formation of an irreversible byproduct (SO42−) during the charge, hindering the progress of AZSBs. Herein, Te–S bonds within S-based cathodes were introduced to enhance electron and ion transport and facilitate the conversion reaction from zinc sulfide (ZnS) to S. This was achieved by constructing heteroatomic TeS-x@Ketjen black composite cathodes (HM-TeS-x@KB, where x = 36, 9, and 4). The HM-TeS-9@KB electrode exhibits long-term cycling stability, maintaining a capacity decay rate of 0.1 % per cycle over 450 cycles at a current density of 10 A g−1. Crucially, through a combination of experimental data analysis and theoretical calculations, the impact mechanism of Te on the charge and discharge of S active materials within the HM-TeS-9@KB cathode in AZSBs was investigated. The presence of Te–S bonds boost the intrinsic conductivity and wettability of the HM-TeS-9@KB cathode. Furthermore, during the charge, the interaction of preferentially oxidized Te with S atoms within ZnS promotes the oxidation reaction from ZnS to S and suppresses the irreversible side reaction between ZnS and H2O. These findings indicate that the heteroatomization of chalcogen S molecules represents a promising approach for enhancing the electrochemical performance of S cathodes in AZSBs.
摘要:
This review provides an overview of the current trends and prospects of the extraction and separation analysis techniques for phenolic compounds in honey in 2012-2022 years. The classification, chemical structures, physicochemical, and bioactive properties of phenolic compounds in honey were comprehensively analyzed. The recent sample preparation techniques for extracting and separating the phenolic compounds from honey were discussed. The advantages and disadvantages of different extraction and separation analyses were also analyzed and compared. According to recent literatures, solid phase extraction and liquid-liquid extraction, two traditional sample preparation techniques, are still widely used for extracting phenolic compounds from honey samples. Various improved microscale extraction methods, such as solid phase microextraction and liquid-liquid microextraction, and sub-technologies can be applied considering the recovery rates, costs, solvent consumption, and environmental impacts. This review will provide insights into the extraction and separation analysis of phenolic compounds, and foster the development and utilization of active components in honey.
摘要:
<jats:title>Abstract</jats:title><jats:p>Hemicyanine dyes, with a tunable optical site and high wavelength tailorability, are of significant importance in the fields of sensing and diagnosis. Following the discovery of the near-infrared (NIR) (650–900 nm) fluorescent dyes Changsha (CS) and Huda (HD) by our group, remarkable progress has been made in the development of hemicyanine-based probes for in vivo imaging and detecting. In this review, we summarize the key contributions made by our group in developing long-wavelength (650–1700 nm) hemicyanines and utilizing them to construct functional probes. Finally, potential drawbacks and future prospects of hemicyanine dyes/probes are discussed.</jats:p><jats:p>1 Introduction</jats:p><jats:p>2 Changsha (CS) Dyes</jats:p><jats:p>3 Huda (HD) Dyes</jats:p><jats:p>4 Construction of Hemicyanine Fluorophores in the NIR-II Region</jats:p><jats:p>5 Summary and Outlook</jats:p>