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Manifestation of Concealed Defects in MoS 2 Nanospheres for Efficient and Durable Electrocatalytic Hydrogen Evolution Reaction
Author(s) -
Senthil Kumar Sakkarapalayam Murugesan,
Selvakumar Karuppiah,
Karthikeyan Jeyakumar,
Thangamuthu Rangasamy,
Murugan Palanichamy,
Rajput Parasmani,
Jha Shambhu Nath,
Bhattacharyya Dibyendu,
Navascues Nuria,
Irusta. Silvia
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201700103
Subject(s) - overpotential , tafel equation , catalysis , adsorption , hydrothermal circulation , materials science , chemical engineering , hydrogen , chemical physics , nanotechnology , chemistry , electrochemistry , electrode , organic chemistry , engineering
MoS 2 nanospheres were formed using a template free hydrothermal process, which exhibit high catalytic activity towards hydrogen evolution reaction (HER). The extend of defect sites are probed by extended X‐ray absorption fine structure which found decrease in co‐ordination number at Mo site rather than at S site. DFT calculations identified an uneven strain and defect distribution between two S planes of curved MoS 2 . Based on hydrogen adsorption on various sites, we identify a new pathway called “extended activity @ shielded defects”, for Volmer‐Tafel and Volmer‐Heyrovsky mechanisms, where H adsorption occurs at exposed S layer driven by defects in underneath S layer of nanosphere. Having higher defect concentration it exhibited excellent HER activity with overpotential of −0.12 V, Tafel slope of 90 mV/decade, and higher turnover frequency. Our findings provide an avenue to design and engineer advanced nanostructures for catalysis, electronic devices, and other potential applications.