WATER SCIENCE AND TECHNOLOGY
·
2022
·Vol. 87
·期 2
·492-507
·
IF 2.43
Jiang Yu,Liu Xinyu,Huang Shikai,Wu Huifang,Liu Haiyan,Liu Shenzhe,Xu Jiale,Wang Kun
In this study, magnetic biochar (Fe-BC) was synthesized from phoenix tree leaves and FeSO 4 ·7H 2 O by impregnation-pyrolysis method, and was used to activate H 2 O 2 to degrade Cu-EDTA. The effects of preparation parameters on the degradation of Cu-EDTA by Fe-BC/H 2 O 2 system were investigated by degradation experiments and characterization methods (SEM, BET, FTIR, XRD and XPS). The results showed that the magnetic biochar prepared under the pyrolysis temperature of 400 °C, pyrolysis time of 3 h and iron content of 3 wt% had the best catalytic activity. Within 120 min, the breaking efficiency of Cu-EDTA binding, precipitation efficiency of Cu 2+ and removal efficiency of TOC could reach 78.48, 71.65 and 46.54% at the conditions of adding 1.0 g/L magnetic biochar and 25 mM H 2 O 2 and the iron dissolution was only 0.32 mg/L. The characterization results and comparison experiments demonstrated that the catalytic effect of magnetic biochar not only depends on the transfer of electrons to H 2 O 2 by the loaded iron oxides, but also the active oxygen functional groups (OFGs) and persistent free radicals (PFRs) contained on the surface can transfer electrons to H 2 O 2 or even dissolved oxygen to produce an amount of hydroxyl radicals ( · OH) and superoxide anion radicals ( ). The use of phoenix tree leaves as the precursor of magnetic biochar provides a new method for the disposal of garden waste, which is in accord with the concept of green and sustainable development. In the degradation system, the magnetic biochar catalyst relies on the OFGs and PFRs of biochar and the metal components loaded to activate H 2 O 2 to generate reactive oxygen species to degrade organic pollutants.
研究领域:
环境化学
·
环境功能材料
·
污染控制化学
·
高级氧化技术
·
废弃物资源化利用
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2018
·Vol. 124
·期 10
·1-8
·
IF 1.604
Mo Xi,Hu Jiamin,Shen Hui,Shui Lingling,Shu Dong,He Junfeng,He Guannan,Wang Yinzhen,Li Wei,He Qinyu
In photocatalyst design, the rapid recombination of photo-generated electron–hole pairs in the bulk or on the surface of semiconductors is a major limiting factor in achieving high photocatalytic efficiency, which is a key scientific issue. Surface modification is used to change the surface properties of photocatalyst related to dark adsorption and photocatalytic efficiency. In this work, micro-sized CuO powder was surface modified by in situ-growing heterojunctions CuO/Cu 2 O and CuO/Cu 2 O/Cu when simply calcinating a mixture of CuO and urea, in which urea acted as a reducing agent. The phases, microstructure, composition, photogenerated carrier lifetime, dark adsorption rate, photodegradation rate, and surface charges of the as-modified powder were investigated. The surface modification was found to change the negative surface charge of micro-sized CuO to a positive one, resulting in enhanced dark adsorption (nearly twice that of pristine CuO). Furthermore, the surface modification prolonged the photogenerated carrier lifetime, which in turn enhanced the photocatalytic efficiency. Overall, this work implies that the electric properties of surface charges and carrier lifetime can be altered by constructing an appropriate heterojunction on the surface of the photocatalyst.
研究领域:
材料科学
·
光催化
·
表面化学
·
半导体物理
·
环境功能材料
·
纳米科技
✓ 已验证
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2020
·
IF 5.627
Zeyun Wu,Yiyang Zhang,Xiaofan Zhao,Hongyan Wang,Shuiqing Li
Yttrium aluminum oxide YAlO 3 is an attractive laser host material for lanthanide ions like Nd 3+ . In this paper, a dual liquid/vapor-fed flame synthesis (DLVF) system is developed for investigating the role of SiO 2 coating on flame-made YAlO 3 :Nd 3+ nanophosphors. The hexamethyldisiloxane (HDMSO) vapor is flexibly fed into the YAlO 3 :Nd 3+ flame spray flow at different positions and molar ratios . We find that the introduction of SiO 2 coating dramatically improves the crystallinity of YAlO 3 :Nd 3+ cores because of the heat-insulation effect and nearly doubles the fluorescence intensity . Through a timescale analysis, we demonstrate that the best timing for coating injection is when the small particles have already been formed but not heavily aggregated. An early injection could result in segregated SiO 2 particles and some impurities like Al 2 SiO 5 , while a delayed injection leads to the coating of SiO 2 on the entire aggregates instead of on individual particles. Experiments of different coating ratios show that the coating ratio 1:1 of Si:(Y+Nd) produces the best crystallinity and strongest fluorescence intensity. Further increase of the coating ratio does not show any improvements of the crystallinity , and may even causes the decrease of the relative fraction of Nd 3+ ions. Compared with YAG:Nd 3+ bulk materials (with a typical optimum doping concentration 1.1mol%) and uncoated YAlO 3 :Nd 3+ nanophosphors (with an optimum doping concentration 2 mol%), the SiO 2 coating promotes the optimum Nd 3+ doping concentration up to 3 mol%.
研究领域:
材料科学
·
无机化学
·
纳米技术
·
发光材料
·
激光增益介质
✓ 已验证
DOI
高影响因子
Nanoscale
·
2016
·Vol. 8
·期 36
·16349-16356
·
IF 7.76
Fengdong Qu,Huifang Jiang,Minghui Yang
The rational design of nanoscale metal oxides with hollow structures and tunable porosity has stimulated tremendous attention due to their vital importance for practical applications. Here, we report the designed synthesis of ZnO/ZnCo2O4 hollow core–shell nanocages (HCSNCs) through a metal–organic framework (MOF) route. The strategy includes the synthesis of a zeolite imidazolate framework-8 (ZIF-8)/Co–Zn hydroxide core–shell nanostructure precursor and subsequent transformation to ZnO/ZnCo2O4 HCSNCs by thermal annealing of the as-prepared precursor in air. Various techniques were employed for characterization of the structure and morphology of the as-prepared ZnO/ZnCo2O4 HCSNCs. When applied as a gas sensing material, the ZnO/ZnCo2O4 HCSNCs show enhanced sensitivity to xylene when compared with ZnCo2O4 shells as well as ZnO nanocages (NCs). In addition, excellent reversibility and superior selectivity of the sensor were observed. The remarkable enhancement in the gas-sensing properties of the ZnO/ZnCo2O4 HCSNCs is attributed to their unique structure and a synergistic effect of ZnO and ZnCo2O4.
研究领域:
材料科学
·
纳米科技
·
传感器技术
·
无机化学
·
功能材料
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 9
·期 5
·2784-2791
·
IF 11.301
Qijun Pei,Teng He,Yang Yu,Zijun Jing,Jintao Wang,Khai Chen Tan,Jianping Guo,Lin Liu,Hujun Cao,Ping Chen
The water–gas shift (WGS) reaction is a key chemical process for CO removal and hydrogen generation in which CO and H2O are converted to CO2 and H2. The activation of H2O at the oxygen vacancy sites of a reducible oxide-supported catalyst is widely viewed as the critical step for this reaction. However, the strategy of rational fabrication of oxygen vacancies in reducible oxides to boost catalytic activity is rarely reported. Here, we report a facile method to fabricate oxygen vacancies through assembling an amorphous titanate overlayer on the surface of TiO2 support via alkali doping, aiming to improve its activity in WGS reaction. TEM, EPR, H2-TPR and XPS results verified that the titanate overlayer is in situ formed via alkali doping, where oxygen vacancies can be rationally regulated during reduction through tuning the amount of alkali. The ease of oxygen vacancy formation induced by alkali doping could be attributed to the lower Ti–O bond energy in titanate. It is shown that sodium-doped Ni/TiO2 with titanate overlayer on the support exhibited superior activity in WGS reaction compared with undoped catalyst, i.e., around threefold greater activity compared with undoped catalyst was achieved at 300 °C. Furthermore, the formation of CH4, a common side reaction in WGS on Ni-based catalysts, is suppressed on the sodium-doped Ni/TiO2. More importantly, the titanate overlayer strategy is successfully extended to other reducible oxide-supported catalysts, which provides a universal method to fabricate oxygen vacancies in reducible oxide-supported catalysts.
研究领域:
催化化学
·
材料科学
·
物理化学
·
能源化学
·
表面科学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2016
·
IF 6.333
Jinglun Wang,Yongjin Mai,Hao Luo,Xiaodan Yan,Lingzhi Zhang
Two fluorosilanes with oligo(ethylene oxide) unites were synthesized through hydrosilylation of chlorosilane with allyl substituted oligo(ethylene oxide) ether followed by fluorination with potassium fluoride . The synthesized fluorosilane compounds exhibited lower viscosity, higher dielectric constant and higher oxidation potential, compared with their non-fluorination counterparts. Difluoro(3-(2-(2-methoxyethoxy)ethoxy)propyl)methylsilane (DFSM 2 ), one of the two compounds, was evaluated as high-voltage and thermal stable electrolyte co-solvent with the conventional carbonate-based electrolytes. Using an optimized electrolyte of 1M LiPF 6 in EC/DFSM 2 /EMC (2/3/5 in vol .) with addition of 5 wt % fluoroethylene carbonate (FEC), high-voltage LiCoO 2 (LCO)/graphite full cell displayed outstanding cycling stability of 92.5% capacity retention after 135 cycles at 4.4 V upper cutoff voltage. Characterized by differential scanning calorimetry (DSC) analysis, the DFSM 2 -based electrolyte demonstrated higher thermal stability with lithiated graphite anode and delithiated LCO cathode, thus better safety feature compared with the conventional electrolyte.
研究领域:
电化学
·
能源材料
·
电池技术
·
有机合成
·
电解质化学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2017
·
IF 4.233
Yunhe Cao,Danyang Chai,Zhiping Luo,Ming Jiang,Weilin Xu,Chuanxi Xiong,Shan Li,Hui Liu,Dong Fang
With a theoretically high capacity and suitable discharge/charge plateaus, lithium vanadates (such as Li 0.04 V 2 O 5 ) can be used as cathode material for lithium ion batteries. Herein, Li 0.04 V 2 O 5 nanowires are densely anchored onto reduced graphene oxide (rGO) nanosheets to form a Li 0.04 V 2 O 5 @rGO nanocomposite by a hydrothermal method with subsequent thermal treatment. Due to this unique structure, the Li 0.04 V 2 O 5 @rGO exhibits remarkable rate performance and excellent cycling stability. Specifically, it delivers a reversible discharge capacity of 738.09 mA h g −1 at a current density of 100 mA g −1 in the voltage range of 2.0–4.0 V. After 500 cycles, it still maintains a high capacity of 731.70 mA h g −1 , which represents 95.01% retention of the original reversible capacity. These results indicate that the Li 0.04 V 2 O 5 @rGO could be a promising candidate as cathode active material for long-term cycling performance in lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
电池技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 23
·15998
·
IF 3.9
Jiehong He,Pin Lv,Jian Zhu,Hexing Li
Correction for ‘Selective CO 2 reduction to HCOOH on a Pt/In 2 O 3 /g-C 3 N 4 multifunctional visible-photocatalyst’ by Jiehong He et al. , RSC Adv. , 2020, 10 , 22460–22467, https://doi.org/10.1039/D0RA03959D .
研究领域:
催化化学
·
环境科学
·
材料科学
·
能源化学
·
光化学
✓ 已验证
DOI
PubMed
高影响因子
Catalysts
·
2019
·Vol. 9
·期 5
·410
·
IF 3.444
Lei Ma,Shiyan Yuan,Taotao Jiang,Xiangming Zhu,Chunshan Lu,Xiaonian Li
Sulfur species (e.g., H2S or SO2) are the natural enemies of most metal catalysts, especially palladium catalysts. The previously reported methods of improving sulfur-tolerance were to effectively defer the deactivation of palladium catalysts, but could not prevent PdO and carrier interaction between sulfur species. In this report, novel sulfur-tolerant SiO2supported Pd4S catalysts (5 wt. % Pd loading) were prepared by H2S–H2aqueous bubble method and applied to catalytic complete oxidation of methane. The catalysts were characterization by X-ray diffraction, Transmission electron microscopy, X-ray photoelectron Spectroscopy, temperature-programmed oxidation, and temperature-programmed desorption techniques under identical conditions. The structural characterization revealed that Pd4S and metallic Pd0were found on the surface of freshly prepared catalysts. However, Pd4S remained stable while most of metallic Pd0was converted to PdO during the oxidation reaction. When coexisting with PdO, Pd4S not only protected PdO from sulfur poisoning, but also determined the catalytic activity. Moreover, the content of Pd4S could be adjusted by changing H2S concentration of H2S–H2mixture. When H2S concentration was 7 %, the Pd4S/SiO2catalyst was effective in converting 96% of methane at the 400 °C and also exhibited long-term stability in the presence of 200 ppm H2S. A Pd4S/SiO2catalyst that possesses excellent sulfur-tolerance, oxidation stability, and catalytic activity has been developed for catalytic complete oxidation of methane.
研究领域:
催化化学
·
环境催化
·
材料化学
·
能源化学
·
表面科学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 20
·6644-6650
·
IF 4.174
Zongtang Li,Xiao Lian,Mingzai Wu,Fangcai Zheng,Yuanhao Gao,Helin Niu
Manganese dioxide (MnO2) is a high-performance anodic material and applied widely in lithium-ion batteries (LIBs). However, some intrinsic limitations originate from the low ionic conductivity, high polarization, and severe volume expansion of this type of material. In this work, we generated a one-dimensional porous MnO2@Co3O4 composite from a MnOOH@ZIF-67 precursor, which is synthesized via a self-assembly strategy. The one-dimensional porous structure provided more active sites and shorter-ion/electron-diffusion distance, thereby enabling higher Li+ storage capacity and better rate capability than a transition metal oxide alone. The Co3O4 coating buffered the volume change during Li+ insertion/extraction, leading to increased cycling stability of the electrode. When evaluated as the anode of LIBs, MnO2@Co3O4 exhibited a reversible capacity of 647 mA h g−1 at 2000 mA g−1 after 400 cycles. This excellent performance indicated that the MnO2@Co3O4 material could be an attractive potential candidate for Li+ storage.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
无机非金属材料
·
功能材料
✓ 已验证
DOI
高影响因子
ANALYST
·
2013
·Vol. 138
·期 16
·4526-4531
·
IF 3.969
Ya Li Liu,Xi Juan Zhao,Xiao Xi Yang,Yuan Fang Li
In this paper, a nanosized porous metal–organic framework, Fe-MIL-88NH2, was facilely prepared with a uniform octahedral shape by the addition of acetic acid, and for the first time was demonstrated to possess intrinsic peroxidase-like activity. Kinetic analysis and electron spin resonance measurements indicated that the catalytic behavior was consistent with typical Michaelis–Menten kinetics and follows a ping-pong mechanism. As a novel peroxidase mimic material, Fe-MIL-88NH2 shows the advantages of high catalytic efficiency, ultrahigh stability and high biocompatibility in aqueous medium compared with natural enzymes and other peroxidase nanomimetics. Here, Fe-MIL-88NH2 was used to quickly catalyze oxidation of the peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2 to produce a colored product, which provided a simple, sensitive and selective method for the colorimetric detection of glucose. Glucose could be linearly detected in the range from 2.0 × 10−6 to 3.0 × 10−4 M with a detection limit of 4.8 × 10−7 M, and the color variation for glucose response was also obvious by visual observation at concentrations as low as 2.0 × 10−6 M. More importantly, the colorimetric method could be successfully applied to the determination of glucose in diluted serum samples.
研究领域:
生物分析化学
·
纳米生物技术
·
酶模拟
·
临床检验
·
分子诊断
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Hongguan Li,Jing Wang,Ruijuan Qi,Yongfeng Hu,Jing Zhang,Hongbin Zhao,Jiujun Zhang,Yufeng Zhao
Charge and spin manipulations of electrons are considered to be of great significance in boosting the catalytic activity of M N C electrocatalysts. However, to the best of our knowledge, most current studies focus only on the charge engineering, the interplay between spin and charge is not well understood, and the simultaneous manipulation of both charge and spin remains challenging. Herein, we show that the cooperative interplay between charge itineration and spin-polarization of electrons has a profound impact on the catalytic behavior through density functional theory (DFT) calculations for the first time. Following this concept, we report a Fe-Ni atomic pair as a superior bifunctional catalyst for high performance ORR and OER, with a very small potential difference (ΔE) of 0.691 V. We confirm that the coexistence of Fe 3d itinerant charge and moderate spin polarization (magnetic moment: 1.48 μ B ) is responsible for the superior functional catalytic activity for the Fe Ni atomic pairs.
研究领域:
电催化
·
材料化学
·
物理化学
·
纳米催化
·
能源材料
·
计算化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）