A study of highly activated hydrogen evolution reaction performance in acidic media by 2D heterostructure of N and S doped graphene on MoOx
Kubra Aydin,
Seongwon Woo,
Vinit Kaluram Kanade,
Seulgi Choi,
Chisung Ahn,
Byungkwon Lim,
Taesung Kim
Affiliations
Kubra Aydin
SKKU Advanced Institute of Nanotechnology (SAINT), Department of Nano Science and Technology Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Seongwon Woo
School of Advanced Material Science and Engineering, Department of Nano Science and Technology Sungkyunkwan University Suwon Gyeonggi‐do Republic of Korea
Vinit Kaluram Kanade
SKKU Advanced Institute of Nanotechnology (SAINT), Department of Nano Science and Technology Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Seulgi Choi
School of Mechanical Engineering Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Chisung Ahn
Heat & Surface Technology R&D Department Korea Institute of Industrial Technology Siheung‐si Gyeonggi‐do Republic of Korea
Byungkwon Lim
School of Advanced Material Science and Engineering, Department of Nano Science and Technology Sungkyunkwan University Suwon Gyeonggi‐do Republic of Korea
Taesung Kim
SKKU Advanced Institute of Nanotechnology (SAINT), Department of Nano Science and Technology Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Abstract Herein, a layer of molybdenum oxide (MoOx), a transition metal oxide (TMO), which has outstanding catalytic properties in combination with a carbon‐based thin film, is modified to improve the hydrogen production performance and protect the MoOx in acidic media. A thin film of graphene is transferred onto the MoOx layer, after which the graphene structure is doped with N and S atoms at room temperature using a plasma doping method to modify the electronic structure and intrinsic properties of the material. The oxygen functional groups in graphene increase the interfacial interactions and electrical contacts between graphene and MoOx. The appearance of surface defects such as oxygen vacancies can result in vacancies in MoOx. This improves the electrical conductivity and electrochemically accessible surface area. Increasing the number of defects in graphene by adding dopants can significantly affect the chemical reaction at the interfaces and improve the electrochemical performance. These defects in graphene play a crucial role in the adsorption of H+ ions on the graphene surface and their transport to the MoOx layer underneath. This enables MoOx to participate in the reaction with the doped graphene. N‐ and S‐doped graphene (NSGr) on MoOx is active in acidic media and performs well in terms of hydrogen production. The initial overpotential value of 359 mV for the current density of −10 mA/cm2 is lowered to 228 mV after activation.
