A series of high surface area graphitic carbon materials （HSGCs） were prepared by ball-milling method. Effect of the graphitic degree of HSGCs on the catalytic performance of Ba-Ru-K/HSGC-x （x is the ball-milling t...A series of high surface area graphitic carbon materials （HSGCs） were prepared by ball-milling method. Effect of the graphitic degree of HSGCs on the catalytic performance of Ba-Ru-K/HSGC-x （x is the ball-milling time in hour） catalysts was studied using ammonia synthesis as a probe reaction. The graphitic degree and pore structure of HSGC-x supports could be successfully tuned via the variation of ball-milling time. Ru nanoparticles of different Ba-Ru-K/HSGC-x catalysts are homogeneously distributed on the supports with the particle sizes ranging from 1.6 to 2.0 nm. The graphitic degree of the support is closely related to its facile electron transfer capability and so plays an important role in improving the intrinsic catalytic performance of Ba-Ru-K/HSGC-x catalyst.展开更多
Carbon nanotubes(CNTs) with abundant surface defects are prepared by a liquid oxidation and thermal annealing method. The defective CNTs-D supported Ba–Ru/CNTs-D catalysts exhibit superior catalytic performance in am...Carbon nanotubes(CNTs) with abundant surface defects are prepared by a liquid oxidation and thermal annealing method. The defective CNTs-D supported Ba–Ru/CNTs-D catalysts exhibit superior catalytic performance in ammonia synthesis with a TOF be increased up to 0.30 s-1, which is 2.5 times of oxidized CNTs-O supported Ba–Ru/CNTs-O catalysts and 5 times of the Ba–Ru/CNTs. The characterizations by CO chemisorption, transmission electron microscope, Raman, and X-ray photoelectron spectroscopy revealed that the uniformly well dispersed Ru NPs can be stabilized on the defective sites of CNTs-D. The great improvement of the catalytic performance and stability of the Ba–Ru/CNTs-D is contributed to the strong interaction between Ru NPs and surface defect of the CNTs.展开更多
Precise control of the pore sizes for porous carbon materials is of importance to study the confinement effect of metal particles because the pore size in nanosize range will decide the physical and chemical propertie...Precise control of the pore sizes for porous carbon materials is of importance to study the confinement effect of metal particles because the pore size in nanosize range will decide the physical and chemical properties of the metal nanoparticles. In this paper, we report a new approach for the synthesis of iron doped ordered mesoporous carbon materials with adjustable pore size using Fe-SBA-15 as hard template and boric acid as the pore expanding reagent. The pore size can be precisely adjusted by a step of 0.4 nm in the range of 3-6 nm. The carbonization temperature can be lowered to 773 K due to the catalytic role of the doped iron. The present approach is suitable for facile synthesis of metal imbedded porous carbon materials with tunable pore sizes.展开更多
We present dC/dV analysis based on the capacitance-voltage(C–V)measurement of quantum-dot lightemitting diodes(QLEDs),and find that some key device operating parameters(electrical and optical turn-on voltage,peak cap...We present dC/dV analysis based on the capacitance-voltage(C–V)measurement of quantum-dot lightemitting diodes(QLEDs),and find that some key device operating parameters(electrical and optical turn-on voltage,peak capacitance,maximum efficiency)can be directly related to the turning points and maximum/minimum of the dC/dV(versus voltage)curve.By the dC/dV study,the behaviors such as low turn-on voltage,simultaneous electrical and optical turn-on process,and carrier accumulation during the device aging can be well explained.Moreover,we perform the C–V and dC/dV measurement of aged devices,and confirm that our dC/dV analysis is correct for them.Thus,our dC/dV analysis method can be applied universally for QLED devices.It provides an in-depth understanding of carrier dynamics in QLEDs through simple C–V measurement.展开更多
Conjugated polymers have been explored as promising hole-transporting layer(HTL)in lead sulfide(PbS)quantum dot(QD)solar cells.The fine regulation of the inorganic/organic interface is pivotal to realize high device p...Conjugated polymers have been explored as promising hole-transporting layer(HTL)in lead sulfide(PbS)quantum dot(QD)solar cells.The fine regulation of the inorganic/organic interface is pivotal to realize high device performance.In this work,we propose using CsPbI_(3) QDs as the interfacial layer between PbS QD active layer and organic polymer HTL.The relative soft perovskite can mediate the interface and form favorable energy level alignment,improving charge extraction and reducing interfacial charge recombination.As a result,the photovoltaic performance can be efficiently improved from 10.50%to 12.32%.This work may provide new guidelines to the device structural design of QD optoelectronics by integrating different solutionprocessed semiconductors.展开更多
基金supported by the Natural Science Foundation of China(NSFC Grant No.20803064)the Natural Science Foundation of Zhejiang Provence(Y4090348 and LY12B03007)Qianjiang Talent Project in Zhejiang Province(2010R10039 and 2013R10056)
文摘A series of high surface area graphitic carbon materials （HSGCs） were prepared by ball-milling method. Effect of the graphitic degree of HSGCs on the catalytic performance of Ba-Ru-K/HSGC-x （x is the ball-milling time in hour） catalysts was studied using ammonia synthesis as a probe reaction. The graphitic degree and pore structure of HSGC-x supports could be successfully tuned via the variation of ball-milling time. Ru nanoparticles of different Ba-Ru-K/HSGC-x catalysts are homogeneously distributed on the supports with the particle sizes ranging from 1.6 to 2.0 nm. The graphitic degree of the support is closely related to its facile electron transfer capability and so plays an important role in improving the intrinsic catalytic performance of Ba-Ru-K/HSGC-x catalyst.
基金The financial support from Natural Science Foundation of Zhejiang Province(LY17B030010)。
文摘Carbon nanotubes(CNTs) with abundant surface defects are prepared by a liquid oxidation and thermal annealing method. The defective CNTs-D supported Ba–Ru/CNTs-D catalysts exhibit superior catalytic performance in ammonia synthesis with a TOF be increased up to 0.30 s-1, which is 2.5 times of oxidized CNTs-O supported Ba–Ru/CNTs-O catalysts and 5 times of the Ba–Ru/CNTs. The characterizations by CO chemisorption, transmission electron microscope, Raman, and X-ray photoelectron spectroscopy revealed that the uniformly well dispersed Ru NPs can be stabilized on the defective sites of CNTs-D. The great improvement of the catalytic performance and stability of the Ba–Ru/CNTs-D is contributed to the strong interaction between Ru NPs and surface defect of the CNTs.
基金supported by the Natural Science Foundation of China (NSFC Grant No. 20803064)the Natural Science Foundation of Zhejiang Province(Y4090348)the Qianjiang Talent Project in Zhejiang Province (2010R10039)
文摘Precise control of the pore sizes for porous carbon materials is of importance to study the confinement effect of metal particles because the pore size in nanosize range will decide the physical and chemical properties of the metal nanoparticles. In this paper, we report a new approach for the synthesis of iron doped ordered mesoporous carbon materials with adjustable pore size using Fe-SBA-15 as hard template and boric acid as the pore expanding reagent. The pore size can be precisely adjusted by a step of 0.4 nm in the range of 3-6 nm. The carbonization temperature can be lowered to 773 K due to the catalytic role of the doped iron. The present approach is suitable for facile synthesis of metal imbedded porous carbon materials with tunable pore sizes.
基金supported by the Key-Area Research and Development Program of Guangdong Province(Grant Nos.2019B010925001 and 2019B010924001)the Shenzhen Peacock Team Project(Grant Nos.KQTD20160301 and 11203005)Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting(Grant Nos.ZDSYS201707 and 281632549)。
文摘We present dC/dV analysis based on the capacitance-voltage(C–V)measurement of quantum-dot lightemitting diodes(QLEDs),and find that some key device operating parameters(electrical and optical turn-on voltage,peak capacitance,maximum efficiency)can be directly related to the turning points and maximum/minimum of the dC/dV(versus voltage)curve.By the dC/dV study,the behaviors such as low turn-on voltage,simultaneous electrical and optical turn-on process,and carrier accumulation during the device aging can be well explained.Moreover,we perform the C–V and dC/dV measurement of aged devices,and confirm that our dC/dV analysis is correct for them.Thus,our dC/dV analysis method can be applied universally for QLED devices.It provides an in-depth understanding of carrier dynamics in QLEDs through simple C–V measurement.
基金supported by the National Natural Science Foundation of China(Nos.92163114,22161142003,52002260,62022081,and 61974099)the Natural Science Foundation of Jiangsu Province of China(No.BK20200872)+3 种基金the State Key Laboratory of applied optics(No.SKLAO2020001A03)Postdoctoral Science Foundation of China(No.2021M702415)This work is also supported by Suzhou Key Laboratory of Functional Nano&Soft Materials,Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project,and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices.K.W.acknowledges the funding support from National Key Research and Development Program(No.2017YFE0120400)National Natural Science Foundation of China(No.61875082).
文摘Conjugated polymers have been explored as promising hole-transporting layer(HTL)in lead sulfide(PbS)quantum dot(QD)solar cells.The fine regulation of the inorganic/organic interface is pivotal to realize high device performance.In this work,we propose using CsPbI_(3) QDs as the interfacial layer between PbS QD active layer and organic polymer HTL.The relative soft perovskite can mediate the interface and form favorable energy level alignment,improving charge extraction and reducing interfacial charge recombination.As a result,the photovoltaic performance can be efficiently improved from 10.50%to 12.32%.This work may provide new guidelines to the device structural design of QD optoelectronics by integrating different solutionprocessed semiconductors.
