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Cu-doped Bi/Bi2WO6 catalysts for efficient N2 fixation by photocatalysis

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1412-1422 doi: 10.1007/s11705-023-2312-1

摘要： In this paper, Cu-doped Bi2WO6 was synthesized via a solvothermal method and applied it in photocatalytic N2 immobilization. Characterization results showed the presence of a small amount of metallic Bi in the photocatalyst, indicating that the synthesized photocatalyst is actually Bi/Cu-Bi2WO6 composite. The doped Cu had a valence state of +2 and most likely substituted the position of Bi3+. The introduced Cu did not affect the metallic Bi content, but mainly influenced the energy band structure of Bi2WO6. The band gap was slightly narrowed, the conduction band was elevated, and the work function was reduced. The reduced work function improved the transfer and separation of charge carriers, which mainly caused the increased photoactivity. The optimized NH3 generation rates of Bi/Cu-Bi2WO6 reached 624 and 243 μmol·L–1·g–1·h–1 under simulated solar and visible light, and these values were approximately 2.8 and 5.9 times higher those of Bi/Bi2WO6, respectively. This research provides a method for improving the photocatalytic N2 fixation and may provide more information on the design and preparation of heteroatom-doped semiconductor photocatalysts for N2-to-NH3 conversion.

关键词： Bi2WO6     Cu doping     work function     photocatalytic N2 fixation     charge separation    

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Visible-light-driven heterostructured g-CN/Bi-TiO floating photocatalyst with enhanced charge carrier

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1417-3

摘要：

• Bi doping in TiO2 enhanced the separation of photo-generated electron-hole.

关键词： Bi doping     Visible light     Algal removal     Charge carrier separation    

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S-enriched porous polymer derived N-doped porous carbons for electrochemical energy storage and conversion

Chao Zhang, Chenbao Lu, Shuai Bi, Yang Hou, Fan Zhang, Ming Cai, Yafei He, Silvia Paasch, Xinliang Feng

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 346-357 doi: 10.1007/s11705-018-1727-6

摘要：

Porous polymers have been recently recognized as one of the most important precursors for fabrication of heteroatom-doped porous carbons due to the intrinsic porous structure, easy available heteroatom-containing monomers and versatile polymerization methods. However, the heteroatom elements in as-produced porous carbons are quite relied on monomers. So far, the manipulating of heteroatom in porous polymer derived porous carbons are still very rare and challenge. In this work, a sulfur-enriched porous polymer, which was prepared from a diacetylene-linked porous polymer, was used as precursor to prepare S-doped and/or N-doped porous carbons under nitrogen and/or ammonia atmospheres. Remarkably, S content can sharply decrease from 36.3% to 0.05% after ammonia treatment. The N content and specific surface area of as-fabricated porous carbons can reach up to 1.32% and 1508 m2·g−1, respectively. As the electrode materials for electrical double-layer capacitors, as-fabricated porous carbons exhibit high specific capacitance of up to 431.6 F·g−1 at 5 mV·s−1 and excellent cycling stability of 99.74% capacitance retention after 3000 cycles at 100 mV·s−1. Furthermore, as the electrochemical catalysts for oxygen reduction reaction, as-fabricated porous carbons presented ultralow half-wave-potential of 0.78 V versus RHE. This work not only offers a new strategy for manipulating S and N doping features for the porous carbons derived from S-containing porous polymers, but also paves the way for the structure-performance interrelationship study of heteroatoms co-doped porous carbon for energy applications.

关键词： porous polymers     porous carbons     sulfur and nitrogen doping     supercapacitor    

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Effect of metal ion-doping on characteristics and photocatalytic activity of TiO

Rongfang YUAN,Beihai ZHOU,Duo HUA,Chunhong SHI

《环境科学与工程前沿（英文）》 2015年 第9卷 第5期   页码 850-860 doi: 10.1007/s11783-014-0737-y

摘要： The effect of ion-doping on TiO nanotubes were investigated to obtain the optimal TiO nanotubes for the effective decomposition of humic acids (HA) through O /UV/ion-doped TiO process. The experimental results show that changing the calcination temperature, which changed the weight fractions of the anatase phase, the average crystallite sizes, the Brunauer-Emmett-Teller surface area, and the energy band gap of the catalyst, affected the photocatalytic activity of the catalyst. The ionic radius, valence state, and configuration of the dopant also affected the photocatalytic activity. The photocatalytic activities of the catalysts on HA removal increased when Ag , Al , Cu , Fe , V , and Zn were doped into the TiO nanotubes, whereas such activities decreased as a result of Mn - and Ni -doping. In the presence of 1.0 at.% Fe -doped TiO nanotubes calcined at 550°C, the removal efficiency of HA was 80% with a pseudo-first-order rate constant of 0.158 min . Fe in TiO could increase the generation of ·OH, which could remove HA. However, Fe in water cannot function as a shallow trapping site for electrons or holes.

关键词： TiO2 nanotubes     ion-doping     humic acids     pseudo-first-order     mechanism    

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Enhanced electrochemical performance of CoNiS@TiCT electrode material through doping of cobalt element

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1440-1449 doi: 10.1007/s11705-023-2333-9

摘要： The composite electrode of CoNiSx and Ti3C2Tx MXene was successfully prepared using a one-step hydrothermal method under the in-situ doping of the cobalt element. The effects of in-situ doping of the cobalt element on the micromorphology and electrochemical performance of the electrodes were investigated. After in-situ doping of the cobalt element, NiS with a needle-like structure was converted into a CoNiSx with petal-like structure. The petal-like CoNiSx with a rough surface was very dense and evenly wrapped on the surface and interlamination of Ti3C2Tx, which helped increase the specific surface area and pore volume of the electrode. Under the identical test conditions, CoNiSx@Ti3C2Tx had a higher specific capacitance and capacitance retention than NiS@Ti3C2Tx. This result indicated that the in-situ doping of the cobalt element promoted the electrochemical performance of the electrode. The energy density of the CoNiSx@Ti3C2Tx/nickel foam (NF)//activated carbon (AC)/NF asymmetric supercapacitor device was 59.20 Wh·kg–1 at a power density of 826.73 W·kg–1, which was much higher than that of NiS@Ti3C2Tx/NF//AC/NF. Three CoNiSx@Ti3C2Tx/NF//AC/NF in series were able to illuminate the light emitting diode lamp for about 10 min, which was higher than the 5 min of three NiS@Ti3C2Tx/NF//AC/NF in series under the same condition. The CoNiSx@Ti3C2Tx/NF//AC/NF with high energy density had better application potential in energy storage than the NiS@Ti3C2Tx/NF//AC/NF.

关键词： MXene     supercapacitor     cobalt doping     structure characterization     electrochemical performance    

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Tuning the electronic structure of NiCoP arrays through V doping for pH-universal hydrogen evolution

Yu Lin, Jinlei Wang, Duanlin Cao, Yaqiong Gong

《化学科学与工程前沿（英文）》 2021年 第15卷 第5期   页码 1134-1146 doi: 10.1007/s11705-020-2014-x

摘要： The exploration of cost-effective, high-performance, and stable electrocatalysts for the hydrogen evolution reaction (HER) over wide pH range (0–14) is of paramount importance for future renewable energy conversion technologies. Regulation of electronic structure through doping vanadium atoms is a feasible construction strategy to enhance catalytic activities, electron transfer capability, and stability of the HER electrode. Herein, V-doped NiCoP nanosheets on carbon fiber paper (CFP) (denoted as V -NiCoP/CFP) were constructed by doping V modulation on NiCoP nanosheets on CFP and used for pH-universal HER. Benefiting from the abundant catalytic sites and optimized hydrogen binding thermodynamics, the resultant V -NiCoP/CFP demonstrates a significantly improved HER catalytic activity, requiring overpotentials of 46.5, 52.4, and 85.3 mV to reach a current density of 10 mA·cm in 1 mol·L KOH, 0.5 mol·L H SO , and 1 mol·L phosphate buffer solution (PBS) electrolytes, respectively. This proposed cation-doping strategy provides a new inspiration to rationally enhance or design new-type nonprecious metal-based, highly efficient, and pH-universal electrocatalysts for various energy conversion systems.

关键词： hydrogen evolution reaction     transition metal phosphides     pH-universal     vanadium doping     carbon fiber paper    

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Tuning nitrogen defects and doping sulfur in carbon nitride for enhanced visible light photocatalytic

《化学科学与工程前沿（英文）》 2023年 第17卷 第1期   页码 93-101 doi: 10.1007/s11705-022-2175-x

摘要： Defect construction and heteroatom doping are effective strategies for improving photocatalytic activity of carbon nitride (g-C3N4). In this work, N defects were successfully prepared via cold plasma. High-energy electrons generated by plasma can produce N defects and embed sulfur atoms into g-C3N4. The N defects obviously promoted photocatalytic degradation performance that was 7.5 times higher than that of pure g-C3N4. The concentration of N defects can be tuned by different power and time of plasma. With the increase in N defects, the photocatalytic activity showed a volcanic trend. The g-C3N4 with moderate concentration of N defects exhibited the highest photocatalytic activity. S-doped g-C3N4 exhibited 11.25 times higher photocatalytic activity than pure g-C3N4. It provided extra active sites for photocatalytic reaction and improved stability of N defects. The N vacancy-enriched and S-doped g-C3N4 are beneficial for widening absorption edge and improving the separation efficiency of electron and holes.

关键词： g-C3N4     nitrogen defect     sulfur doping     photodegradation     plasma    

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Enhancement of open circuit voltage in organic solar cells by doping a fluorescent red dye

Qing LI, Junsheng YU, Yue ZANG, Nana WANG, Yadong JIANG

《能源前沿（英文）》 2012年 第6卷 第2期   页码 179-183 doi: 10.1007/s11708-012-0177-y

摘要： The open circuit voltage ( ) of small-molecule organic solar cells (OSCs) could be improved by doping suitable fluorescent dyes into the donor layers. In this paper, 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) was used as a dopant, and the performance of the OSCs with different DCJTB concentration in copper phthalocyanine (CuPc) was studied. The results showed that the of the OSC with 50% of DCJTB in CuPc increased by 15%, compared with that of the standard CuPc/fullerene (C ) device. The enhancement of the was attributed to the lower highest occupied molecular orbital (HOMO) level in the DCJTB than that in the CuPc. Also, the light absorption intensity is enhanced between 400 and 550 nm, where CuPc and C have low absorbance, leading to a broad absorption spectrum.

关键词： organic solar cells (OSCs)     open circuit voltage     fluorescent dye doping     4-(dicyanomethylene)-2-t-butyl-6-(1     1     7     7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB)    

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Effects of Pd doping on N

Mingxin Dong, Jun Wang, Jinxin Zhu, Jianqiang Wang, Wulin Wang, Meiqing Shen

《环境科学与工程前沿（英文）》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0976-9

摘要： N O is a powerful greenhouse gas and plays an important role in destructing the ozone layer. This present work investigated the effects of Pd doping on N O formation over Pt/BaO/Al O catalyst. Three types of catalysts, Pt/BaO/Al O , Pt/Pd mechanical mixing catalyst (Pt/BaO/Al O +Pd/Al O ) and Pt-Pd co-impregnation catalyst (Pt-Pd/BaO/Al O ) were prepared by incipient wetness impregnation method. These catalysts were first evaluated in NSR activity tests using H /CO as reductants and then carefully characterized by BET, CO chemisorption, CO-DRIFTs and H -TPR techniques. In addition, temperature programmed reactions of NO with H /CO were conducted to obtain further information about N O formation mechanism. Compared with Pt/BaO/Al O , (Pt/BaO/Al O +Pd/Al O ) produced less N O and more NH during NO storage and reduction process, while an opposite trend was found over (Pt-Pd/BaO/Al O +Al O ). Temperature programmed reactions of NO with H /CO results showed that Pd/Al O component in (Pt/BaO/Al O +Pd/Al O ) played an important role in NO reduction to NH , and the formed NH could reduce NO to N leading to a decrease in N O formation. Most of N O formed over (Pt-Pd/BaO/Al O +Al O ) was originated from Pd/BaO/Al O component. H -TPR results indicated Pd-Ba interaction resulted in more difficult-to-reduce PdO species over Pd/BaO/Al O , which inhibits the NO dissociation and thus drives the selectivity to N O in NO reduction.

关键词： NOx storage reduction     Pt/BaO/Al2O3     Pd doping     N2O formation     Optimization    

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CeO doping boosted low-temperature NH-SCR activity of FeTiO catalyst: A microstructure analysis and reaction

《环境科学与工程前沿（英文）》 2022年 第16卷 第5期 doi: 10.1007/s11783-022-1539-2

摘要：

• CeO2 doping significantly improved low-temperature NH3-SCR activity on FeTiOx.

关键词： NH3-SCR     CeO2 doping     Low-temperature NOx removal     Improved redox property     In situ XAFS analysis    

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Topology optimization of piezoelectric bi-material actuators with velocity feedback control

Mariana MORETTI, Emílio C. N. SILVA

《机械工程前沿（英文）》 2019年 第14卷 第2期   页码 190-200 doi: 10.1007/s11465-019-0537-y

摘要： In recent years, the new technologies and discoveries on manufacturing materials have encouraged researchers to investigate the appearance of material properties that are not naturally available. Materials featuring a specific stiffness, or structures that combine non-structural and structural functions are applied in the aerospace, electronics and medical industry fields. Particularly, structures designed for dynamic actuation with reduced vibration response are the focus of this work. The bi-material and multifunctional concepts are considered for the design of a controlled piezoelectric actuator with vibration suppression by means of the topology optimization method (TOM). The bi-material piezoelectric actuator (BPEA) has its metallic host layer designed by the TOM, which defines the structural function, and the electric function is given by two piezo-ceramic layers that act as a sensor and an actuator coupled with a constant gain active velocity feedback control (AVFC). The AVFC, provided by the piezoelectric layers, affects the structural damping of the system through the velocity state variables readings in time domain. The dynamic equation analyzed throughout the optimization procedure is fully elaborated and implemented. The dynamic response for the rectangular four-noded FE analysis is obtained by the Newmark’s time-integration method, which is applied to the physical and the adjoint systems, given that the adjoint formulation is needed for the sensitivity analysis. A gradient-based optimization method is applied to minimize the displacement energy output measured at a predefined degree-of-freedom of the BPEA when a transient mechanical load is applied. Results are obtained for different control gain values to evaluate their influence on the final topology.

关键词： topology optimization method     bi-material piezoactuator     active velocity feedback control     time-domain transient analysis     host structure design     vibration suppression    

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Bi-modes alternation stepping ultrasonic motors

JIN Jiamei, ZHAO Chunsheng

《机械工程前沿（英文）》 2008年 第3卷 第1期   页码 101-105 doi: 10.1007/s11465-008-0018-1

摘要： Based on the principle of alternative operation of two bending vibration modes in an annular stator, this paper presents a standing-wave stepping ultrasonic motor characterized by no accumulative errors driven by an open-loop control circuitry. The driving forces are generated from the motions of projections on the stator in two modes. The positioning of the motor is achieved by the cooperation between the stator projections and rotor teeth, and the number of the rotors determines the stepping angle of the motor. Two-phase sinusoidal signals corresponding to the two modal frequencies drive the motor bi-direction stepping rotation via a switch unit. The prototype runs steadily without miss-step on trial. The single-step angle displacement of the motor is 2.5°.

关键词： miss-step     bi-direction     Two-phase sinusoidal     positioning     accumulative    

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Acoustic characteristics of bi-directional turbines for thermoacoustic generators

Dongdong LIU, Yanyan CHEN, Wei DAI, Ercang LUO

《能源前沿（英文）》 2022年 第16卷 第6期   页码 1027-1036 doi: 10.1007/s11708-020-0702-3

摘要： Bi-directional turbines combined with rotary motors may be a feasible option for developing high power thermoacoustic generators with low cost. A general expression for the acoustic characteristics of the bi-directional turbine was proposed based on theoretical derivation, which was validated by computational fluid dynamics modeling of an impulse turbine with fixed guide vanes. The structure of the turbine was optimized primarily using steady flow with an efficiency of near 70% (the shaft power divided by the total energy consumed by the turbine). The turbine in the oscillating flow was treated in a lumped-parameter model to extract the acoustic impedance characteristics from the simulation results. The key acoustic impedance characteristic of the turbine was the resistance and inertance due to complex flow condition in the turbine, whereas the capacitance was treated as an adiabatic case because of the large-scale flow channel relative to the heat penetration depth. Correlations for the impedance were obtained from both theoretical predictions and numerical fittings. The good fit of the correlations shows that these characteristics are valid for describing the bi-directional turbine, providing the basis for optimization of the coupling between the thermoacoustic engine and the turbine using quasi-one-dimensional theory in the frequency domain.

关键词： thermoacoustic power generator     acoustic characteristics     bi-directional impulse turbine     energy conversion    

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Enhanced Fenton-like process over Cu/L(+)-ascorbic acid co-doping mesoporous silica for toxicity reduction

《环境科学与工程前沿（英文）》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1804-7

摘要：

● Cu-C-MSNs are developed via a co-doping step of Cu with L(+)-ascorbic acid.

关键词： Cation-π structures     Polarization electric field     Fenton-like process     Contaminants cleavage    

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Modeling the impact of uncertainty in emissions trading markets with bankable permits

Yongliang ZHANG, Bing ZHANG, Jun BI, Pan HE

《环境科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 231-241 doi: 10.1007/s11783-012-0431-x

摘要： The various forms of uncertainty that firms may face in bankable emission permit trading markets will affect firms’ decision making as well as their market performance. This research explores the effect of increased uncertainty over future input costs and output prices on the temporal distribution of emission. In a dynamic programming setting, the permit price is a convex function of stochastic prices of coal and electricity. Increased uncertainty about future market conditions increases the expected permit price and causes a risk neutral firm to reduce ex ante emissions in order to smooth out marginal abatement costs over time. Finally, safety valves, both low-side and high-side, are suggested to reduce the impact of uncertainty in bankable emission trading markets.

关键词： uncertainty     bankable     emission trading     market performance    

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标题 作者 时间 类型 操作

Cu-doped Bi/Bi2WO6 catalysts for efficient N2 fixation by photocatalysis

期刊论文

Visible-light-driven heterostructured g-CN/Bi-TiO floating photocatalyst with enhanced charge carrier

期刊论文

S-enriched porous polymer derived N-doped porous carbons for electrochemical energy storage and conversion

Chao Zhang, Chenbao Lu, Shuai Bi, Yang Hou, Fan Zhang, Ming Cai, Yafei He, Silvia Paasch, Xinliang Feng

期刊论文

Effect of metal ion-doping on characteristics and photocatalytic activity of TiO

Rongfang YUAN,Beihai ZHOU,Duo HUA,Chunhong SHI

期刊论文

Enhanced electrochemical performance of CoNiS@TiCT electrode material through doping of cobalt element

期刊论文

Tuning the electronic structure of NiCoP arrays through V doping for pH-universal hydrogen evolution

Yu Lin, Jinlei Wang, Duanlin Cao, Yaqiong Gong

期刊论文

Tuning nitrogen defects and doping sulfur in carbon nitride for enhanced visible light photocatalytic

期刊论文

Enhancement of open circuit voltage in organic solar cells by doping a fluorescent red dye

Qing LI, Junsheng YU, Yue ZANG, Nana WANG, Yadong JIANG

期刊论文

Effects of Pd doping on N

Mingxin Dong, Jun Wang, Jinxin Zhu, Jianqiang Wang, Wulin Wang, Meiqing Shen

期刊论文

CeO doping boosted low-temperature NH-SCR activity of FeTiO catalyst: A microstructure analysis and reaction

期刊论文

Topology optimization of piezoelectric bi-material actuators with velocity feedback control

Mariana MORETTI, Emílio C. N. SILVA

期刊论文

Bi-modes alternation stepping ultrasonic motors

JIN Jiamei, ZHAO Chunsheng

期刊论文

Acoustic characteristics of bi-directional turbines for thermoacoustic generators

Dongdong LIU, Yanyan CHEN, Wei DAI, Ercang LUO

期刊论文

Enhanced Fenton-like process over Cu/L(+)-ascorbic acid co-doping mesoporous silica for toxicity reduction

期刊论文

Modeling the impact of uncertainty in emissions trading markets with bankable permits

Yongliang ZHANG, Bing ZHANG, Jun BI, Pan HE

期刊论文