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.
Original language | English |
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Pages (from-to) | 8400-8409 |
Number of pages | 10 |
Journal | ACS Sustainable Chemistry and Engineering |
Volume | 6 |
Issue number | 7 |
DOIs | |
State | Published - 2 Jul 2018 |
Keywords
- Electrocatalyst
- Heterostructures
- Hydrogen evolution
- MoS
- WS