The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform

Hao Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Boosting the on-demand hydrogen generation from aqueous ammonia borane by the visible-light-driven synergistic Electron Effect in antenna-reactor-type catalysts with plasmonic copper spheres and noble-metal-free nanoparticles
    Chemical Engineering Journal, 2020
    Co-Authors: Hao Zhang, Jin Song, Dong Wang
    Abstract:

    Abstract To tailor the Electronic behavior of catalytically active species in heterogeneous catalysts is beneficial for regulating their catalytic performance in various reaction including hydrogen generation. Herein, we rationally synthesize a series of antenna-reactor-type catalysts with the combination of plasmonic Cu spheres (55, 130, 190, 270 and 440 nm) with catalytically active Co or Ni nanoparticles (NPs), which are used for hydrogen generation from aqueous ammonia borane (NH3BH3) at 298 K. All the catalysts show the higher activities under visible light irradiation than in the dark and the optimal Co-based catalyst has the highest room-temperature photocatalytic activity with the total turnover frequency (TOF) value of 164.8 min−1, which outperforms the values of all the reported non-noble metal catalysts. The capture of photogenerated Electrons, the monochromatic light-dependent activity and hydrogen generation of different catalysts verify that there exists the visible-light-driven synergistic Electron Effect bewteen plasmonic Cu spheres with energetic Electrons and Co NPs with excited Electrons generated by interband transitions. This leads to the Electron density enrichment of Co NPs and the resultantly enhanced hydrogen generation activity under visible light irradiation.

  • Remarkably boosting catalytic H-2 evolution from ammonia borane through the visible-light-driven synergistic Electron Effect of non-plasmonic noble-metal-free nanoparticles and photoactive metal-organic frameworks
    Applied Catalysis B: Environmental, 2018
    Co-Authors: Jin Song, Jia Cheng, Na Fan, Hao Zhang
    Abstract:

    Abstract From the viewpoint of regulating and enriching the Electron density of noble-metal-free nanoparticles (NPs) to remarkably enhance their catalytic activities in the reduction-dominated reactions, we synthesized a series of non-plasmonic Co and Ni nanoparticles (NPs) supported by NH 2 -functionalized photoactive and NH 2 -free non-photoactive metal-organic frameworks (MOFs) with different compositions and framework structures, which were used to catalyze H 2 evolution from ammonia borane (NH 3 BH 3 ) in aqueous solution under visible light irradiation at 298 K. The systematic investigation showed that the catalysts containing photoactive MOFs had higher activities than those containing non-photoactive MOFs under visible light irradiation though the photocatalytic activities of all the catalysts were enhanced in comparison with the activities in the dark. Specifically, the Co catalysts containing photoactive MOFs had the total turnover frequency (TOF) values in the range of 81.7–117.7 min −1 , which were much higher than the values of reported noble-metal-free catalysts and were even comparable to the values of noble metal catalysts. The remarkably enhanced activities of the supported catalysts could be attributed to the visible-light-driven synergistic Electron Effect of semiconductor-like MOFs and non-plasmonic noble-metal-free NPs, which was verified by the increased photocurrent density of Co/MIL-101(Cr)-NH 2 . Moreover, the catalysts still had 100% of H 2 selectivity and high activities after 25 runs of catalysis.

Roman Sobolewski - One of the best experts on this subject based on the ideXlab platform.

  • hot Electron Effect in superconductors and its applications for radiation sensors
    Superconductor Science and Technology, 2002
    Co-Authors: Alexei Semenov, G N Goltsman, Roman Sobolewski
    Abstract:

    The paper reviews the main aspects of nonequilibrium hot-Electron phenomena in superconductors and various theoretical models developed to describe the hot-Electron Effect. We discuss implementation of the hot-Electron avalanche mechanism in superconducting radiation sensors and present the most successful practical devices, such as terahertz mixers and direct intensity detectors, for far-infrared radiation. Our presentation also includes the novel approach to hot-Electron quantum detection implemented in superconducting x-ray to optical photon counters.

R S Gupta - One of the best experts on this subject based on the ideXlab platform.

  • Channel thermal noise of SOI MOSFET in high-frequency region
    Semiconductor Science and Technology, 2005
    Co-Authors: Nirupama Kapoor, Subhasis Haldar, Mridula Gupta, R S Gupta
    Abstract:

    An accurate thermal noise model to predict the HF noise performance of submicron SOI MOSFETs is developed in which the Effect of lattice temperature and channel length modulation is taken into consideration in addition to the hot Electron Effect. In the analysis, the lattice temperature dependent mobility has been used to evaluate the spectral density of drain current noise. The results so obtained are compared with the experimental data and are in good agreement.

  • physics based analytical modeling of potential and electrical field distribution in dual material gate dmg mosfet for improved hot Electron Effect and carrier transport efficiency
    IEEE Transactions on Electron Devices, 2002
    Co-Authors: Manoj Saxena, Subhasis Haldar, Maneesha Gupta, R S Gupta
    Abstract:

    We propose a new two-dimensional (2-D) analytical model of a dual material gate MOSFET (DMG-MOSFET) for reduced drain-induced barrier lowering (DIBL) Effect, merging two metal gates of different materials, laterally into one. The arrangement is such that the work function of the gate metal near the source is higher than the one near the drain. The model so developed predicts a step-function in the potential along the channel, which ensures screening of the drain potential variation by the gate near the drain. The small difference of voltage due to different gate material keeps a uniform electric field along the channel, which in turn improves the carrier transport efficiency. The ratio of two metal gate lengths can be optimized along with the metal work functions and oxide thickness for reducing the hot Electron Effect. The model is verified by comparison to the simulated results using a 2-D device simulator ATLAS over a wide range of device parameters and bias conditions.

Jin Song - One of the best experts on this subject based on the ideXlab platform.

  • Boosting the on-demand hydrogen generation from aqueous ammonia borane by the visible-light-driven synergistic Electron Effect in antenna-reactor-type catalysts with plasmonic copper spheres and noble-metal-free nanoparticles
    Chemical Engineering Journal, 2020
    Co-Authors: Hao Zhang, Jin Song, Dong Wang
    Abstract:

    Abstract To tailor the Electronic behavior of catalytically active species in heterogeneous catalysts is beneficial for regulating their catalytic performance in various reaction including hydrogen generation. Herein, we rationally synthesize a series of antenna-reactor-type catalysts with the combination of plasmonic Cu spheres (55, 130, 190, 270 and 440 nm) with catalytically active Co or Ni nanoparticles (NPs), which are used for hydrogen generation from aqueous ammonia borane (NH3BH3) at 298 K. All the catalysts show the higher activities under visible light irradiation than in the dark and the optimal Co-based catalyst has the highest room-temperature photocatalytic activity with the total turnover frequency (TOF) value of 164.8 min−1, which outperforms the values of all the reported non-noble metal catalysts. The capture of photogenerated Electrons, the monochromatic light-dependent activity and hydrogen generation of different catalysts verify that there exists the visible-light-driven synergistic Electron Effect bewteen plasmonic Cu spheres with energetic Electrons and Co NPs with excited Electrons generated by interband transitions. This leads to the Electron density enrichment of Co NPs and the resultantly enhanced hydrogen generation activity under visible light irradiation.

  • Remarkably boosting catalytic H-2 evolution from ammonia borane through the visible-light-driven synergistic Electron Effect of non-plasmonic noble-metal-free nanoparticles and photoactive metal-organic frameworks
    Applied Catalysis B: Environmental, 2018
    Co-Authors: Jin Song, Jia Cheng, Na Fan, Hao Zhang
    Abstract:

    Abstract From the viewpoint of regulating and enriching the Electron density of noble-metal-free nanoparticles (NPs) to remarkably enhance their catalytic activities in the reduction-dominated reactions, we synthesized a series of non-plasmonic Co and Ni nanoparticles (NPs) supported by NH 2 -functionalized photoactive and NH 2 -free non-photoactive metal-organic frameworks (MOFs) with different compositions and framework structures, which were used to catalyze H 2 evolution from ammonia borane (NH 3 BH 3 ) in aqueous solution under visible light irradiation at 298 K. The systematic investigation showed that the catalysts containing photoactive MOFs had higher activities than those containing non-photoactive MOFs under visible light irradiation though the photocatalytic activities of all the catalysts were enhanced in comparison with the activities in the dark. Specifically, the Co catalysts containing photoactive MOFs had the total turnover frequency (TOF) values in the range of 81.7–117.7 min −1 , which were much higher than the values of reported noble-metal-free catalysts and were even comparable to the values of noble metal catalysts. The remarkably enhanced activities of the supported catalysts could be attributed to the visible-light-driven synergistic Electron Effect of semiconductor-like MOFs and non-plasmonic noble-metal-free NPs, which was verified by the increased photocurrent density of Co/MIL-101(Cr)-NH 2 . Moreover, the catalysts still had 100% of H 2 selectivity and high activities after 25 runs of catalysis.

T. P. - One of the best experts on this subject based on the ideXlab platform.

  • Back-channel hot-Electron Effect on the front-channel characteristics in thin-film SOI MOSFETs
    IEEE Electron Device Letters, 1991
    Co-Authors: B. Zhang, T. P.
    Abstract:

    The front-channel I-V characteristics in thin-film SOI MOSFETs have been studied before and after back-channel hot-Electron stress. As a result of Electron trapping in the buried oxide near the drain junction, this stress causes the following changes: (1) a reduction of the channel current for a given gate voltage; (2) the appearance of the kink Effect when measured in the reverse mode (with source and drain interchanged); and (3) an increased breakdown voltage when measured in the reverse mode. Both the kink Effect and the change in the breakdown behavior can be attributed to the increased barrier height of the drain-body junction resulting from the localized Electron trapping in the buried oxide. >