The Experts below are selected from a list of 47247 Experts worldwide ranked by ideXlab platform

Hyun-seok Kim - One of the best experts on this subject based on the ideXlab platform.

  • improved hydrogen evolution reaction performance using mos2 ws2 heterostructures by Physicochemical Process
    ACS Sustainable Chemistry & Engineering, 2018
    Co-Authors: Dhanasekaran Vikraman, Sajjad Hussain, Kamran Akbar, Linh Truong, Adaikalam Kathalingam, Seung-hyun Chun, Jongwan Jung, Hui Joon Park, Hyun-seok Kim
    Abstract:

    This report describes the synthesis of a layered molybdenum disulfide (MoS2)–tungsten disulfide (WS2) heterostructure onto fluorine doped tin oxide covered glass substrates using a combination of chemical bath deposition and RF sputtering techniques. FESEM images revealed that the MoS2–WS2 heterostructure surface consisted of a cauliflower structured array of grains with spherical structures. The vertically aligned atomic layers were explored by transmission electron microscopy images for MoS2–WS2 heterostructure. Hydrogen evolution reaction (HER) kinetics show overpotentials of 151 and 175 mV @ 10 mA/cm2 with Tafel slope values of 90 and 117 mV/decade for pristine MoS2 and WS2 electrocatalysts, respectively. Improved electrocatalytic activity for HER was established with overpotential 129 mV @ 10 mA/cm2 and Tafel slope 72 mV/decade for the MoS2–WS2 heterostructure. The MoS2–WS2 heterostructure electrocatalyst showed robust continuous HER performance over 20 h in an acidic solution. This improved electroc...

  • Improved Hydrogen Evolution Reaction Performance using MoS2–WS2 Heterostructures by Physicochemical Process
    2018
    Co-Authors: Dhanasekaran Vikraman, Sajjad Hussain, Kamran Akbar, Linh Truong, Adaikalam Kathalingam, Seung-hyun Chun, Jongwan Jung, Hui Joon Park, Hyun-seok Kim
    Abstract:

    This report describes the synthesis of a layered molybdenum disulfide (MoS2)–tungsten disulfide (WS2) heterostructure onto fluorine doped tin oxide covered glass substrates using a combination of chemical bath deposition and RF sputtering techniques. FESEM images revealed that the MoS2–WS2 heterostructure surface consisted of a cauliflower structured array of grains with spherical structures. The vertically aligned atomic layers were explored by transmission electron microscopy images for MoS2–WS2 heterostructure. Hydrogen evolution reaction (HER) kinetics show overpotentials of 151 and 175 mV @ 10 mA/cm2 with Tafel slope values of 90 and 117 mV/decade for pristine MoS2 and WS2 electrocatalysts, respectively. Improved electrocatalytic activity for HER was established with overpotential 129 mV @ 10 mA/cm2 and Tafel slope 72 mV/decade for the MoS2–WS2 heterostructure. The MoS2–WS2 heterostructure electrocatalyst showed robust continuous HER performance over 20 h in an acidic solution. This improved electrochemical performance emerges from the elevation of electron–hole separation at the layer interfaces and sharing of active edge sites through the interface. This study provides the basis to develop new applications for transition-metal dichalcogenides heterostructures in future energy conversion systems

Quan Xie - One of the best experts on this subject based on the ideXlab platform.

  • geochemical controls on wettability alteration at pore scale during low salinity water flooding in sandstone using x ray micro computed tomography
    Fuel, 2020
    Co-Authors: Yongqiang Chen, Nilesh Kumar Jha, Duraid Albayati, Maxim Lebedev, Mohammad Sarmadivaleh, Stefan Iglauer, Ali Saeedi, Quan Xie
    Abstract:

    Abstract We performed a pore-scale multiphase flow experiment on a sandstone core sample. We imaged the core sample at initial oil saturation, residual oil saturations after high salinity and low salinity water flooding. Moreover, we examined fluid occupancy maps and water cluster size distribution at pore-scale before and after low salinity waterflooding. Furthermore, we performed a geochemical study to relate Physicochemical Process at sub-pore scale to account for in-situ wettability alteration at pore-scale. Micro-CT imaging shows that low salinity waterfloodng yielded 5% of residual oil saturation reduction after high salinity water flooding. Fluid occupancy maps within pore network show water film propagation at pore surface during low salinity water flooding, suggesting the oil film detachment from pore surfaces due to in-situ wettability alteration. Micro-CT imaging analysis also shows that the large size water cluster (greater than 107 µm3) occupies 87.7% of water volume after high salinity water flooding, whereas the same size water cluster occupies 89.6% pore volume after low salinity water flooding, implying that water clusters coalesce into each other to transport in pore network during low salinity water flooding in line with fluid occupancy maps. Geochemical modelling predicts a pH increase (from 7 to 8.9) during low salinity water flooding largely due to ankerite and albite dissolution. This study sheds light on the significance of geochemical controls over wettability alteration at pore-scale through water film propagation.

Kamran Akbar - One of the best experts on this subject based on the ideXlab platform.

  • improved hydrogen evolution reaction performance using mos2 ws2 heterostructures by Physicochemical Process
    ACS Sustainable Chemistry & Engineering, 2018
    Co-Authors: Dhanasekaran Vikraman, Sajjad Hussain, Kamran Akbar, Linh Truong, Adaikalam Kathalingam, Seung-hyun Chun, Jongwan Jung, Hui Joon Park, Hyun-seok Kim
    Abstract:

    This report describes the synthesis of a layered molybdenum disulfide (MoS2)–tungsten disulfide (WS2) heterostructure onto fluorine doped tin oxide covered glass substrates using a combination of chemical bath deposition and RF sputtering techniques. FESEM images revealed that the MoS2–WS2 heterostructure surface consisted of a cauliflower structured array of grains with spherical structures. The vertically aligned atomic layers were explored by transmission electron microscopy images for MoS2–WS2 heterostructure. Hydrogen evolution reaction (HER) kinetics show overpotentials of 151 and 175 mV @ 10 mA/cm2 with Tafel slope values of 90 and 117 mV/decade for pristine MoS2 and WS2 electrocatalysts, respectively. Improved electrocatalytic activity for HER was established with overpotential 129 mV @ 10 mA/cm2 and Tafel slope 72 mV/decade for the MoS2–WS2 heterostructure. The MoS2–WS2 heterostructure electrocatalyst showed robust continuous HER performance over 20 h in an acidic solution. This improved electroc...

  • Improved Hydrogen Evolution Reaction Performance using MoS2–WS2 Heterostructures by Physicochemical Process
    2018
    Co-Authors: Dhanasekaran Vikraman, Sajjad Hussain, Kamran Akbar, Linh Truong, Adaikalam Kathalingam, Seung-hyun Chun, Jongwan Jung, Hui Joon Park, Hyun-seok Kim
    Abstract:

    This report describes the synthesis of a layered molybdenum disulfide (MoS2)–tungsten disulfide (WS2) heterostructure onto fluorine doped tin oxide covered glass substrates using a combination of chemical bath deposition and RF sputtering techniques. FESEM images revealed that the MoS2–WS2 heterostructure surface consisted of a cauliflower structured array of grains with spherical structures. The vertically aligned atomic layers were explored by transmission electron microscopy images for MoS2–WS2 heterostructure. Hydrogen evolution reaction (HER) kinetics show overpotentials of 151 and 175 mV @ 10 mA/cm2 with Tafel slope values of 90 and 117 mV/decade for pristine MoS2 and WS2 electrocatalysts, respectively. Improved electrocatalytic activity for HER was established with overpotential 129 mV @ 10 mA/cm2 and Tafel slope 72 mV/decade for the MoS2–WS2 heterostructure. The MoS2–WS2 heterostructure electrocatalyst showed robust continuous HER performance over 20 h in an acidic solution. This improved electrochemical performance emerges from the elevation of electron–hole separation at the layer interfaces and sharing of active edge sites through the interface. This study provides the basis to develop new applications for transition-metal dichalcogenides heterostructures in future energy conversion systems

Zhiqun Lin - One of the best experts on this subject based on the ideXlab platform.

  • inorganic modified semiconductor tio2 nanotube arrays for photocatalysis
    Energy and Environmental Science, 2014
    Co-Authors: Mengye Wang, James Ioccozia, Lan Sun, C J Lin, Zhiqun Lin
    Abstract:

    Semiconductor photocatalysis is a promising Physicochemical Process for the photodegradation of organic contaminants and bacterial detoxification. Among various oxide semiconductor photocatalysts, TiO2 has garnered considerable attention because of its outstanding properties including strong oxidizing activity, chemical and mechanical stability, corrosion resistance, and nontoxicity. This Review briefly introduces the key mechanisms of photocatalysis, highlights the recent developments pertaining to pure TiO2 nanotube arrays and TiO2 nanotube arrays modified by non-metals, metals and semiconductors, and their applications in the photocatalytic degradation of organic dyes. The improved photocatalytic efficiencies of modified TiO2 nanotube arrays are compared with unmodified counterparts. Current challenges and prospective areas of interest in this rich field are also presented.

Dhanasekaran Vikraman - One of the best experts on this subject based on the ideXlab platform.

  • improved hydrogen evolution reaction performance using mos2 ws2 heterostructures by Physicochemical Process
    ACS Sustainable Chemistry & Engineering, 2018
    Co-Authors: Dhanasekaran Vikraman, Sajjad Hussain, Kamran Akbar, Linh Truong, Adaikalam Kathalingam, Seung-hyun Chun, Jongwan Jung, Hui Joon Park, Hyun-seok Kim
    Abstract:

    This report describes the synthesis of a layered molybdenum disulfide (MoS2)–tungsten disulfide (WS2) heterostructure onto fluorine doped tin oxide covered glass substrates using a combination of chemical bath deposition and RF sputtering techniques. FESEM images revealed that the MoS2–WS2 heterostructure surface consisted of a cauliflower structured array of grains with spherical structures. The vertically aligned atomic layers were explored by transmission electron microscopy images for MoS2–WS2 heterostructure. Hydrogen evolution reaction (HER) kinetics show overpotentials of 151 and 175 mV @ 10 mA/cm2 with Tafel slope values of 90 and 117 mV/decade for pristine MoS2 and WS2 electrocatalysts, respectively. Improved electrocatalytic activity for HER was established with overpotential 129 mV @ 10 mA/cm2 and Tafel slope 72 mV/decade for the MoS2–WS2 heterostructure. The MoS2–WS2 heterostructure electrocatalyst showed robust continuous HER performance over 20 h in an acidic solution. This improved electroc...

  • Improved Hydrogen Evolution Reaction Performance using MoS2–WS2 Heterostructures by Physicochemical Process
    2018
    Co-Authors: Dhanasekaran Vikraman, Sajjad Hussain, Kamran Akbar, Linh Truong, Adaikalam Kathalingam, Seung-hyun Chun, Jongwan Jung, Hui Joon Park, Hyun-seok Kim
    Abstract:

    This report describes the synthesis of a layered molybdenum disulfide (MoS2)–tungsten disulfide (WS2) heterostructure onto fluorine doped tin oxide covered glass substrates using a combination of chemical bath deposition and RF sputtering techniques. FESEM images revealed that the MoS2–WS2 heterostructure surface consisted of a cauliflower structured array of grains with spherical structures. The vertically aligned atomic layers were explored by transmission electron microscopy images for MoS2–WS2 heterostructure. Hydrogen evolution reaction (HER) kinetics show overpotentials of 151 and 175 mV @ 10 mA/cm2 with Tafel slope values of 90 and 117 mV/decade for pristine MoS2 and WS2 electrocatalysts, respectively. Improved electrocatalytic activity for HER was established with overpotential 129 mV @ 10 mA/cm2 and Tafel slope 72 mV/decade for the MoS2–WS2 heterostructure. The MoS2–WS2 heterostructure electrocatalyst showed robust continuous HER performance over 20 h in an acidic solution. This improved electrochemical performance emerges from the elevation of electron–hole separation at the layer interfaces and sharing of active edge sites through the interface. This study provides the basis to develop new applications for transition-metal dichalcogenides heterostructures in future energy conversion systems