Journal of Food Measurement and Characterization
·
2024
·Vol. 18
·期 5
·3569-3576
·
IF 2.9
Liu Shanshan,Zhang Yu
This study analyzed the anthocyanin content and antioxidant properties of five mulberry ( Morus spp. ) varieties, including black ( M. nigra ), red ( M. rubra ) and white ( M. alba ) types. Anthocyanins were extracted and analyzed using HPLC–MS, which revealed four major pigments: cyanidin-3-glucoside, cyanidin-3-rutinoside, cyanidin-3,5-diglucoside and pelargonidin-3-glucoside. Total anthocyanins were significantly higher in black mulberries Bom irangi (185 mg/100 g) and Kalmi (158 mg/100 g) compared to 28–60 mg/100 g in other varieties, consistent with their dark fruit color. Electrochemical analysis by cyclic voltammetry showed oxidation peak potentials (E pa ) of key anthocyanins: + 368 mV for cyanidin; + 830 mV for cyanidin-3-glucoside; and + 912 mV for pelargonidin-3-glucoside. Lower E pa indicates easier oxidation and greater antioxidant activity. DPPH radical scavenging assays revealed strongest potency for Bom irangi (EC50 42 μg/mL) and Kalmi (EC50 58 μg/mL), again due to high anthocyanin levels. Further, a negative correlation (R 2 = 0.923) was demonstrated between E pa values and EC50, proving excellent predictive ability of electrochemical data for estimating antioxidant capacity. Cyanidin with lowest E pa (+ 368 mV) and highest hydroxylation exhibited strongest activity (EC50 35 μg/mL). Overall, the study successfully demonstrated the antioxidant potential of mulberry anthocyanins, especially from black varieties, using advanced analytical strategies.
研究领域:
植物学
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食品科学
·
分析化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2013
·
IF 4.675
Pengran Gao,Weixin Lv,Rui Zhang,Yi Liu,Guanghua Li,Xianfu Bu,Lixu Lei
We have developed a novel route to make new batteries from spent ones, in which we obtain and regenerate the active materials of positive electrode and negative electrode respectively. For the spent lead acid batteries , the positive electrode active materials contain both PbSO 4 and PbO 2 . To make full use of them, we have to investigate the treatment of the mixtures rather than only PbO 2 , which we have reported previously. Here we report our investigation on three mixtures of PbSO 4 and PbO 2 in different mole ratios, as well as the electrode materials directly from the spent batteries. The mixtures are firstly desulphated, and then solvothermally processed in methanol at 140 °C for 24 h. The as-obtained solids contain both PbO·PbCO 3 and PbCO 3 , which have been calcined to form α-PbO. The α-PbO powders are similar irregular particles and highly electrochemically active, which discharge around 170 mAh g −1 at 5 mA g −1 , 80 mAh g −1 at 200 mA g −1 and 60 mAh g −1 at 400 mA g −1 with excellent cyclic stability in 50 cycles.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Lin Chen,Rong Chen,Xun Zhu,Qiang Liao,Dingding Ye,Yang Yang,Jun Zhang,Youxu Yu,Yuxin Liu
In this work, we propose polydopamine inspired dual-functional template in the form of microspheres to prepare the TiO 2 photoanode for a photocatalytic fuel cell. This new type template can not only ensure easy control of porous structure , which enhances mass transport and light scattering, but also enable nitrogen doping into TiO 2 for visible-light response, which increases solar utilization. Because of these merits, the photoanode prepared by using this polydopamine inspired dual-functional template yields better photoelectrochemical activity. The newly-developed photoanode is also evaluated by incorporating it into a photocatalytic fuel cell in terms of electricity generation . Experimental results further confirm that the photocatalytic fuel cell with the photoanode prepared by using the polydopamine microspheres shows superior performance than does the one with conventional TiO 2 photoanode. Effects of the size of polydopamine microspheres and its ratio to TiO 2 are also studied. It is shown that the photoanode prepared by using 220-nm polydopamine microspheres at a ratio of 1:5 exhibits optimal performance. This study provides a new route to prepare high-performance photoanode.
研究领域:
材料科学
·
能源科学
·
光电催化
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产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 46
·28949-28960
·
IF 3.361
Ze Lv,Zhen Chen,Qiang Yu,Wei Zhu,Hongjun You,Bangyao Chen,Zhaoyi Zheng,Yuanyuan Liu,Qi Hu
PbO2–Co3O4–MnO2 electrodes, used in the electrowinning industry and in the degradation of organic pollutants, have demonstrated an elevated performance through macroscopic electrochemical measurements. However, few reports have investigated localized electrochemical performance, which plays an indispensable role in determining the essential reasons for the improvement of the modified material. In this study, the causes of the increase in electrochemical reactivity are unveiled from a micro perspective through scanning electrochemical microscopy (SECM), X-ray diffraction (XRD), Raman microscopy (Raman), and X-ray photoelectronic energy spectroscopy (XPS). The results show that the increase of electrochemical reactivity of the modified electrodes results from two factors: transformation of the microstructure and change in the intrinsic physicochemical properties. Constant-height scanning maps indicate that the electrochemical reactivity of the modified electrodes is higher than that of the PbO2 electrode on the whole and high-reactivity areas are orderly distributed, coinciding with the observations from SEM and XRD. Thus, one of the reasons for the improvement of the modified electrode performance is the refinement of the microscopic morphology. The other reason is the surge of the oxygen vacancy concentration on the surface of the coating, which is supported by XRD, Raman and XPS. This finding is detected by the probe approach curve (PAC), which can quantitatively characterize the electrochemical reactivity of a substrate. Heterogeneous charge transfer rate constants of the modified electrode are 4–5 times higher than that of the traditional PbO2 electrode. This research offers some insight into the electrochemical reactivity of modified PbO2 electrodes from a micro perspective.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2024
·Vol. 14
·期 1
·1-10
·
IF 3.8
Zhu Dancheng,Wu Yifan,Zheng Kai,Xu Hao,Chen Chao,Qiao Jun,Shen Chao
In this study, we deposited Ti 3 C 2 T x -modified, rare-earth-doped PbO 2 on the surface of a carbon fabric via electrodeposition. The surface morphology and electronic structure of the electrode were characterized with SEM, XRD and XPS. The layered Ti 3 C 2 T x did not change the structure of β-PbO 2 , and at the same time, it improved the crystallinity of the material and reduced the grains of PbO 2 . Electrochemical experiments showed that the addition of Ti 3 C 2 T x increased the electrochemical activity of the electrode and produced more H 2 O 2 , which contributed to the degradation of pollutants. The efficiency of sulfamethoxazole (SMX) degradation reached 95% after 120 min at pH 3 with a current density of 50 mA/cm 2 . Moreover, the electrode has good cycling performance, and the degradation efficiency was still 80% after 120 min after 10 cycles of recycling. Based on the intermediates identified by HPLC‒MS, a mechanism for SMX degradation was proposed. Our results will provide a new idea for the development of efficient electrocatalytic degradation of antibiotics.
研究领域:
环境科学
·
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBON
·
2021
·
IF 9.594
Xiang Gao,Wei Liu,Tianqi Wang,Jingrou Dai,Yuanyuan Pan,Yongxu Du,Yongpeng Cui,Hongguang Fan,Shuang Liu,Yongcheng Jin
N-doping can endow carbon materials with high electrochemical activity. Besides the widely validated sp 2 -hybridized nitrogen doping, sp -hybridized nitrogen ( sp - N ) atoms are also expected to be new active sites. However, both sp - N atoms and cyano (CN) groups containing sp - N are rarely produced in carbon materials presently. In this work, the first cyano groups-modified carbon materials are synthesized firstly via an interesting struggle between the chemical etching of KOH and the catalytic graphitization of Co nanoparticles in carbon frameworks. The theoretical calculations and experimental results manifest that the stronger electronegativity of CN groups renders carbon materials a higher electrochemical activity. As K + storage anodes, the CN − modified carbon materials exhibit an obvious boost in potassium storage performance in both ester- and ether-based electrolytes. Therefore, as a new N doping form, the successful introduction of CN groups into carbon materials opens a door for exploring sp -N doped carbon materials for applications in energy storage and other fields.
研究领域:
材料科学
·
能源存储
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Ying Liu,Luoyuan Xie,Wang Zhang,Ziwen Dai,Wei Wei,Shaojuan Luo,Xian Chen,Wei Chen,Feng Rao,Lei Wang,Yang Huang
Owing to its electronic conductivity and electrochemical reactivity, polyaniline (PANI) can serve as the cathode for rechargeable zinc-ion batteries (ZIBs). However, it suffers from fast deactivation and thus performance deterioration because of spontaneous deprotonation during charge/discharge. Here, we report an effective strategy to improve the electrochemical reactivity and stability of the PANI-based cathode by constructing a π-electron conjugated system between PANI and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) on carbon nanotubes (CNTs). The impressive performance of the post-treated CNTs–PANI–PEDOT:PSS (t-CNTs–PA–PE) cathode is largely attributed to the −SO3–H+ groups in PSS, which acts as an internal proton reservoir and provides enough H+ for PANI’s protonation, thus promoting its electrochemical activity and reversibility. Besides, the strong interactions between PANI and PEDOT:PSS assist the stretching of π–π conjugation chains, bringing about enhanced electronic conductivity. Consequently, the t-CNTs–PA–PE cathode achieves a high capacity of 238 mA h g–1, together with good rate capability and long-term stability (over 1500 cycles with 100% Coulombic efficiency). Through exerting the freestanding t-CNTs–PA–PE, a flexible ZIB was further constructed with both outstanding electrochemical properties and superior high safety. This work demonstrates the availability of conducting polymer cathodes for high-performance ZIBs, fulfilling the need of flexible electronics.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CORROSION SCIENCE
·
2018
·
IF 4.862
Zhenzhen Jin,Yubing Qiu,Zhenyu Chen,Xingpeng Guo
The effect of doping anions on the degradation of electrochemical activity of polypyrrole (PPy)/A (A: SO 4 2− , pTS − , PSS − , and GO) films in NaOH is investigated by various electrochemical methods and microscopic analyses. The degradation rates of PPy/A films follow first-order k inetics. The PPy/SO 4 and PPy/GO films have two degradation stages with higher rate constants ( k ), while the PPy/pTS and PPy/PSS films just show one degradation stage with much lower k values. The exchange ability of doping anions with OH − and the penetration of OH − into the inner film are two crucial factors for the degradation of PPy in NaOH.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2020
·
IF 4.032
Kai Qi,Zhenzhen Jin,Dan Wang,Zhenyu Chen,Xingpeng Guo,Yubing Qiu
The degradation of electrochemical activity is the inevitable and noticeable issue in the widespread applications of conducting polypyrrole (PPy), which involves chemical and electrochemical reactions in PPy natural degradation processes. Based on thorough insights into PPy degradation behavior, this work develops a method of theoretical derivation for the natural degradation kinetics model of PPy, which is verified in NaOH aqueous electrolytes and could be further generalized in other media. The kinetics model derives the rate equations of the chemical and electrochemical processes ( v c and v e ) in PPy degradation. The relationships of the electroactivity degradation rate constant ( k deg ) and rate constants of the chemical and electrochemical processes ( k c and k e ) as well as reaction orders of PPy n+ and OH − are established through theoretical deduction. The effects of doping anions in PPy, film thickness, and electrolyte temperature on the degradation kinetics are investigated through theoretical considerations and experimental findings. The degradation level and service failure time of PPy can be effectively predicted using the kinetics model. Establishing the degradation kinetics model would signal the new perspective and depth in comprehensive studies of PPy degradation, finally facilitating the optimization of performance management in PPy practical applications.
研究领域:
材料科学
·
电化学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Chemosensors
·
2023
·Vol. 11
·期 4
·250
·
IF 4.2
Liang Wang,Jianxin Yi
Monitoring the concentration of hydrogen is very important as it is a flammable and explosive gas. Non-Nernstian potentiometric hydrogen sensors hold promising potentials for the sensitive detection of hydrogen. This paper reports the improved H2-sensing performance of a mixed oxide ion-electron conducting (MIEC) Pr0.1Ce0.9O2−δ(PCO) electrode using Fe2O3surface modification. The Fe2O3-modified PCO exhibited a high response of −184.29 mV to 1000 ppm H2at 450 °C. The response values exhibited a linear or logarithmic dependence on the H2concentration for below or above 20 ppm, respectively. A sensitivity of −74.9 mV/decade in the concentration range of 20–1000 ppm was achieved, and the theoretical limit of detection was calculated to be 343 ppb. Moreover, a power-law relationship between the response time and the concentration value was also found. Electrochemical impedance analyses revealed that the excellent H2-sensing performance may be attributed to the large ratio of the electrochemical activity of the hydrogen oxidation reaction (HOR) over the oxygen exchange reaction (OER). In addition, the distribution of relaxation time (DRT) results reveal that the enhanced electrochemical kinetics caused by H2presence in air is mainly related to acceleration of the electrode surface processes.Keywords:solid electrolyte;potentiometric gas sensor;Fe2O3surface modification;electrochemical activity
研究领域:
材料科学
·
传感器技术
✓ 已验证
DOI
高影响因子
IONICS
·
2022
·Vol. 28
·期 9
·4273-4282
·
IF 2.961
Gao Jiayi,Yang Yujie,Ren Yujie,Zhu Wenjie,Li Jin,Liu Yongguang,Dai Lei,Wang Ling,He Zhangxing
Vanadium redox flow batteries have the advantages of long life, flexible design, safety, and reliability, so they have broad development prospects in the field of energy storage. Borides are extensively used in electrochemistry due to their excellent electrical conductivity. In this program, HfB 2 was used as catalyst for the V 3+ /V 2+ pair. The catalytic effect was verified by electrochemical impedance spectroscopy and cyclic voltammetry. The result shows that the cell using HfB 2 as negative catalyst can exhibit excellent rate capability when the current density is 50 ~ 125 mA cm −2 . At 125 mA cm −2 , the discharge capacity of the modified cell is 68.7 mA h, which is much higher than pristine cell (22.8 mA h). And the energy efficiency of pristine cells is 11.2% lower than that of modified cells. These consequences suggest that HfB 2 is a catalyst with promising prospects to enhance electrochemical activity of V 3+ /V 2+ redox reaction in VRFB.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2016
·
IF 7.354
Lin Li,Rong Chen,Xun Zhu,Qiang Liao,Hong Wang,Liang An,Muxing Zhang
In this work, a novel photoanode with a cascading gradient pore microstructure is proposed to enhance photoelectrochemical and photocatalytic activities, which consists of a nanocrystalline TiO 2 layer synthesized by the sol–gel method, a microporous layer, and a macroporous layer formed by adding PEG and PMMA as the template, respectively. The gradient pore microstructure can not only enhance the mass and photon transfer and improve the light utilization, but also increase the electrical conductivity and restrain the recombination of photoexcited electron–hole pairs. Furthermore, the cascading design helps to establish tighter interparticle connections between layers. Because of these merits, it has been found that the cascading gradient pore microstructured photoanode exhibited a 63% improvement over the conventional photoanode in terms of photoelectrochemical activity. This new design also enhanced the photocatalytic activity, leading to a much higher methylene blue degradation efficiency (76.7%) than that of conventional photoanodes (62.5%). The effect of the PMMA/TiO 2 ratio on the structure and performance of the proposed photoanode was also investigated. The highest performance was achieved with a PMMA/TiO 2 ratio of 1:1. The obtained results establish a new avenue for designing the photoanodes of photoelectrochemical systems.
研究领域:
材料科学
·
能源科学
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）