ACS Applied Energy Materials
·
2023
·
IF 6.4
Guandong Wang,Wenjuan Xiang,Huize Liu,Yizhi Yin,Dandan Ma,Jinfu Ma
The key to the development of metal–air batteries is the research on efficient and stable non-noble metal bifunctional electrocatalysts that can simultaneously catalyze the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in the same electrolyte. Ce–O–C single-component materials have abundant oxygen vacancies and commendable electrical conductivity; therefore, they have great application potential in bifunctional catalysis. However, their application is limited by the harsh synthesis conditions (pyrolysis at >1750 °C). Herein, CeO2C2/NC material is obtained during the pyrolysis of Ce-MOF at 900 °C, and it is found that the CeO2C2/NC material has a satisfactory ORR/OER bifunctional catalytic effect. In addition, CeO2C2/NC possesses good electrochemical properties, such as ORR Eonset = 0.92 V, E1/2 = 0.83 V (vs reversible hydrogen electrode (RHE)), and an excellent Tafel slope of 77.7 mV dec–1, outperforming the commercial Pt/C catalyst. X-ray photoelectron spectroscopy (XPS) analysis reveals that Ce3+ and its chemisorbed oxygen (Oβ) percentages of 50.33 and 79.37%, respectively, are the main reasons for the production of abundant oxygen vacancies. The prepared Ce–O–C series material will be applied to zinc–air batteries (ZABs), which is expected to improve the comprehensive performance of ZABs. The results can provide ideas for the development of ORR/OER single-component bifunctional catalysts.
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高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Xiaoli Yi,Hongyue Luo,Yongmao Zhou,Shihao Feng,Jiexi Wang,Zhixing Wang,Jianguo Duan,Ding Wang,Huajun Guo,Guochun Yan
Na 3 V 2 (PO 4 ) 2 F 3 is considered as one of the most promising cathode materials for sodium-ion batteries (SIBs). However, the low electronic conductivity of this material severely restricts its electrochemical performance. Herein, Cr-doped Na 3 V 2 (PO 4 ) 2 F 3 /C material was synthesized by a simple sol-gel method, and the effects of Cr 3+ doping on the structure, morphology and electrochemical performance were systematically investigated. The optimized material Na 3 V 2-x Cr x (PO 4 ) 2 F 3 /C (x = 0.05) exhibits high initial discharge capacity of 101.9 mAh g −1 at 10 C and keep a capacity retention of 68.7 % after 1000 cycles. The improved electrochemical performance can be attributed to the higher crystallinity, improved intrinsic electronic conductivity and sodium ion diffusion coefficient due to the doped Cr 3+ , which accelerates the electron transport and charge transfer rate. The optimized Cr-doped Na 3 V 2 (PO 4 ) 3 F 3 /C material obtained in this work can promote the practical application of Na 3 V 2 (PO 4 ) 3 F 3 cathode.
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高影响因子
NANOTECHNOLOGY
·
2022
·Vol. 33
·期 41
·415404
·
IF 3.953
Wenjuan Xiang,Yanling Li,Mengxue Wu,Jinfu Ma,Zhilin Sheng
The development of electrocatalysts for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with high-activity and atability still remain great challenges for rechargeable Zn-air batteries. Herein, a new type of Co-doped Ce–N–C bifunctional electrocatalyst has been synthesized through a simple two-step method, which realizes the high dispersion of Co3O4 on the CeO2 carbon frame and stabilizes its specific surface area. Benefiting from the synergistic interaction between Co3O4 and CeO2, the conductivity of the electrocatalyst is improved and the oxygen reduction reaction/oxygen storage properties are promoted. The resultant Co3O4-CeO2@N–C catalyst shows remarkable ORR activity with the high initial potential (E0 = 0.8 V), the large limiting current density (jL = 6 mA cm−2), and a low Tafel slope (81 mV dec−1). In full cell tests, Co3O4-CeO2@NC as the oxygen electrode exhibites superior charge/discharge capacity and excellent cycle stability. The assembled Zn-air battery achieves a maximum power density of 110 mW cm−2 at a current density of 180 mA cm−2, and a high specific capacity of 780 mAh g−1 at a discharge current density of 10 mA cm−2.
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高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2022
·
IF 11.357
Mengxue Yang,Zexi Hou,Xin Zhang,Baoyu Gao,Yanwei Li,Yanan Shang,Qinyan Yue,Xiaoguang Duan,Xing Xu
Single-atom catalysts (SACs)-based peroxymonosulfate (PMS) systems are highly selective to the type of organic pollutants while the mechanisms remain ambiguous. In this work, we carried out experimental and theoretical investigations to reveal the origins of selectivity of radical and nonradical pathways in a designated Co–N4–C/PMS system. Two typical pollutants [bisphenol A (BPA) and metronidazole (MNZ)] with different molecular structures were employed for comparison. We found that radical oxidation (SO4•– and HO•) and nonradical electron-transfer pathway (ETP) co-existed in the Co–N4–C/PMS system. Pollutants (e.g., MNZ) with a high redox potential were degraded primarily by free radicals rather than ETP, while the oxidization of low-redox pollutants (e.g., BPA) was dominated by ETP at the surface region of Co–N4–C which overwhelmed the contributions of radicals in the homogeneous phase. Intriguingly, the contributions of radical and nonradical pathways could be manipulated by the PMS loading, which simultaneously increased the radical population and elevated the oxidation potential of Co–N4–C-PMS* complexes in ETP. Findings from this work will unravel the mysterious selective behavior of the SACs/PMS systems in the oxidation of different micropollutants.
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高影响因子
Chemistry-An Asian Journal
·
2022
·Vol. 17
·期 12
·e202200288
·
IF 4.839
Tao Liu,Xuemin Yin,Xiuping Yin,Shuling Cheng,Xuan Wang,Yufeng Zhao
Niobium-based oxides have attracted a lot of attention as anode materials for sodium-ion batteries (SIBs) due to their high theoretical specific capacity, excellent rate capability and exceptional safety. However, their poor intrinsic electronic conductivity and sluggish sodium ions diffusion kinetics severely hinder their practical applicability. Here, SnNb 2 O 6 @C was successfully prepared by a simple solid-state reaction technique coupled with carbon coating. HRTEM images show that the SnNb 2 O 6 @C particles are covered with uniformly ultrathin amorphous carbon layer of about 1.8 nm, thus improving the electronic conductivity and diffusion coefficient of sodium ions. As anode for SIBs, the as-obtained SnNb 2 O 6 @C material exhibits excellent specific capacity (369 mAh g −1 at a current density of 50 mA g −1 ) and remarkable rate performance (177 mAh g −1 at 1000 mA g −1 ), which indicates its good prospect in practical application.
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高影响因子
ENERGY & FUELS
·
2022
·
IF 4.654
Zhi-long Xu,Hong-bo Huang,Cai-ling Liu,Shao-hua Luo,Qing-long Wang,Li-guo Jin,Gui-dong Dong,Hai-long Lu
For SnO2 that was used as an anode material for potassium-ion batteries (KIBs), the theoretical capacity is rarely high. However, due to the excessively huge volume expansion of SnO2 in the electrode reaction, the battery capacity decreases sharply, thus impeding its practical application. Here, potassium stannate and glucose were dissolved in the hydrothermal phase and dispersed evenly through a one-step hydrothermal method and then calcined and carbonized at a high temperature in an argon atmosphere to obtain a SnO2@C composite. To obtain an electrode with better performance, SnO2@C/MCB (micrometer carbon ball) composites were synthesized by a similar method. SnO2@C/MCB exhibited a high initial reversible capacity, splendid rate property, and cycling performance in KIBs (the initial capacity remains at 57.2% after 450 cycles). Compared with the SnO2@C material, the SnO2@C/MCB electrode has a higher electrical conductivity, smaller volume change, and better potassium storage capacity.
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高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2018
·Vol. 24
·期 49
·12932-12937
·
IF 5.16
Guozhen Zhu,Qing Li,Renchao Che
Graphical On the ball : The high charge/discharge voltage (1.65 V), long life span, and excellent reversibility of TiNb 2 O 7 have led to its use as an anode for lithium ion batteries. In order to overcome its inherent poor electronic conductivity, it is herein formed as hollow spheres, and coated with carbon, resulting in a much-improved anode performance. TiNb 2 O 7 , with high charge/discharge voltage (1.65 V), long life span, and excellent reversibility has become a new anode material for lithium ion batteries in recent years. However, the inherent poor electronic conductivity strictly limits its practical applications. Herein, we report for the first time hollow TiNb 2 O 7 @C spheres, with carbon spheres as sacrificial template. The special hollow structure can effectively relieve the volume expansion during the repeated process of charging/discharging. The conductivity of hollow TiNb 2 O 7 spheres can be greatly improved by the carbon layers uniformly coated outside the surface of TiNb 2 O 7 spheres. Besides, the particle aggregation can be conspicuously suppressed by the uniformly coated carbon layers. As a result, hollow TiNb 2 O 7 @C spheres show a prominent charge/discharge capacity of 282.6/283.8 mAh g −1 after 100 cycles at 0.25 C (1 C=388 mA g −1 ), revealing the excellent cycle performance and high reversible capacity. Meanwhile, the charge/discharge capacity of 157.5 and 157.9 mAh g −1 can be maintained at 10 C after 10 cycles. The facial synthetic method can be extended to prepare various materials with volume expansion during repeated charging/discharging process.
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高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Ruixue Shi,Tianbao Liu,Jing Lu,Xiangjing Liang,Andrei Ivanets,Junqin Yao,Xintai Su
Biochar derived from municipal sludge can be applied to adsorption. But it usually requires activation and pickling due to the generation of impurities such as metal oxide particles, which is uneconomical. Here, a facile strategy, acidification-one-step calcination, was developed and sludge-based Fe–C materials with good Cr(VI) removal effect were obtained by regulating the amount of hydrochloric acid . The results show that the adsorption capacity of Fe/C-5 (the best sample) for Cr(VI) was 150.84 mg g −1 . According to the Langmuir isotherm and pseudo-second-order kinetic model, the removal of Cr(VI) by Fe/C-5 is spontaneous and endothermic chemisorption process. In addition, Fe/C-5 has good ability to remove Cr(VI) under the interference of coexisting ions, and has good cycle stability. The removal of Cr(VI) by Fe/C-5 is considered to be synergistic process of adsorption and reduction. The Fe atoms were highly dispersed in Fe/C-5 and tightly bonded with C atoms, which not only strengthened the Cr(VI) adsorption by electrostatic attraction, but also activated the C atoms in the biochar material, so that the C atoms can reduce Cr(VI) to Cr(III) under acidic conditions. This may be due to the fact that acid pretreatment converted the iron in municipal sludge in the form of Fe–O/OH to free Fe 3+ and entered the C lattice during the calcination process. In this work, Fe–C materials with excellent Cr(VI) adsorption capacity were prepared by one-step calcination method, which has important reference significance for the resource utilization of municipal sludge.
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高影响因子
CARBON
·
2022
·
IF 11.307
Dangcheng Su,Yuanhua Xiao,Yingliang Liu,Shengang Xu,Shaoming Fang,Shaokui Cao,Xuezhao Wang
2D MXenes (transition metal carbides, Ti 3 C 2 T x ) with large surface area and metallic conductivity are widely used as supporters in catalysts. Unfortunately, the single MXene sheets would deteriorate in the presence of oxygen and water, which is almost the same as the environment of oxygen reduction reaction (ORR). Herein, an “armor” was constructed to encapsulate the oxidizable MXene by a confined in-situ oxidative polymerization strategy, employing the electrostatic interaction between the exfoliated MXene sheets (negatively charged) and oxidant (Fe 3+ , positively charged). The ultra-dispersed binary Fe 3 N and Co sits coupled with the large surface area MXene supporter synergy to endow more exposed active sites, meanwhile, the density functional theory (DFT) studies reveal that a moderate binding strength between the intermediates and the binary active sites was effectively modulated to enhance the ORR performance. The synthesized Fe 3 N/Co–N–C@MXene exhibits an impressive half-wave potential (E 1/2 , 0.871V) and a lower Tafel slope of 52.56 mV dec −1 than that of Pt–C-20% (74.89 mV dec −1 ). The Fe 3 N/Co–N–C@MXene based ZAB exhibits a four times higher peak power density (189.16 mW cm −2 ) than the Pt–C-20% based ZABs and superior cycle stability within 320 h. Furthermore, the assembled flexible ZABs shows high flexibility and stability in different bending scenarios.
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高影响因子
Nanoscale
·
2014
·Vol. 6
·期 14
·7954-7958
·
IF 6.739
Wenya Cai,Xianghu Tang,Bai Sun,Liangbao Yang
In this study, multifunctional Fe3O4/C/Au nanoparticles (NPs), which catalytically integrated active small Au NPs with surface-enhanced Raman scattering (SERS) active large Au NPs, were fabricated via a facile method and employed for the in situ SERS monitoring of a catalytic reaction of p-nitrothiophenol (p-NTP) to p-aminothiophenol (p-ATP). In addition, the effect of magnet power was tested and it was demonstrated that the SERS intensity of the reaction system was stronger, and the reaction proceeded more smoothly because more hot spots existed and remained the same in the magnetic field; hence, the catalytic rate could be determined.
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高影响因子
Advanced Science
·
2022
·Vol. 9
·期 26
·2201573
·
IF 17.521
Fangwen Cheng,Fang Cao,Binwen Chen,Xinfeng Dai,Ziheng Tang,Yifei Sun,Jun Yin,Jing Li,Nanfeng Zheng,Binghui Wu
Power conversion efficiency (PCE) and long-term stability are two vital issues for perovskite solar cells (PSCs). However, there is still a lack of suitable hole transport layers (HTLs) to endow PSCs with both high efficiency and stability. Here, NiO x nanoparticles are promoted as an efficient and 85 °C/85%-stable inorganic HTL for high-performance n-i-p PSCs, with the introduction of perovskite quantum dots (QDs) between perovskite and NiO x as systematic interfacial engineering. The QD intercalation enhances film morphology and assembly regulation of NiO x HTLs . Due to structure–function correlations, hole mobility within NiO x HTL is improved. And the hole extraction from perovskite to NiO x is also facilitated, resulting from reduced trap states and optimized energy level alignments. Hence, the promoted NiO x -based n-i-p PSCs exhibit high PCE (21.59%) and excellent stability (sustaining 85 °C aging in air without encapsulation). Furthermore, encapsulated solar modules with QDs-promoted NiO x HTLs show impressive stability during 85 °C/85% aging test for 1000 hours. With high transparency, QDs-promoted NiO x is also demonstrated to be an advanced HTL for semitransparent PSCs. This work develops promising NiO x inorganic HTL in n-i-p PSCs for manufacturing next-generation photovoltaic devices.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Yu Su,Rong Fan,Jiabao Li,Yangxi Liu,Ziyuan Zheng,Xin Zhou,Xiang Feng,Yibin Liu,Hui Zhao,Xiaobo Chen,Xingong Zhang,Chaohe Yang,Hao Yan
Oxidation of fatty alcohols to fatty acids is still challenging due to the sluggish activation of the C–H bond over Au supported on reducible oxides with a coordination-saturated structure. Herein, we constructed an efficient interfacial Auδ−–OV–Ti structure by tuning the crystal forms of TiO2. Compared with TiO2-rutile exposed by (110) and (111) crystal facets, TiO2-anatase can exploit the defect (101) crystal facet to obtain rich oxygen vacancies (OV), inducing electron migration from TiO2-anatase support to Au species to form electron-rich Auδ− species. Specifically, the synergistic catalytic effect between the OV–Ti and Auδ− species greatly enhances the adsorption of alcohol and thereby overcomes sluggish activation of the C–H bond caused by the electron pushing effect triggered by long carbon chains. Consequently, the Au/TiO2-anatase catalyst shows excellent isooctyl alcohol conversion (69.5%) and isocaprylic acid selectivity (67.9%) under base-free conditions. The catalytic system is further extended to the oxidation of other fatty alcohols to fatty acids with excellent catalytic performance.
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高影响因子
危险品化学品经营许可证（带存储）