A study of highly activated hydrogen evolution reaction performance in acidic media by 2D heterostructure of N and S doped graphene on MoO_x

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.

Recent advances in nitrogen-doped graphene-based heterostructures and composites: mechanism and active sites for electrochemical ORR and HER

“…Thus, to overcome these limitations, Aydin et al developed a hybrid catalyst consisting of N and S-doped graphene and MoO x , and then analysed its activity towards the HER. 90 In this report, layered MoO x was synthesized, and then a thin film of graphene was transferred to it, followed by doping with N and S. The HER analysis showed that the as-developed hybrid catalyst showed a significantly improved catalytic performance with significantly low overpotential of 359 mV at 10 mA cm −2 compared to pure graphene and MoO x . The observed enhanced activity was attributed to the presence of oxygen in graphene, which resulted in the better electrical contact and interfacial interactions between graphene and MoO x .…”

“…Recently, Aydin et al developed an N- and S-doped graphene 2D heterostructure on MoOx for efficient hydrogen generation. 90 In this report, firstly graphene and MoOx were synthesized separately. For the synthesis of graphene, the thermal CVD approach was used by employing Cu foil as the growth substrate.…”

Enhanced electron penetration triggering interfacial charge redistribution in N-doped graphene-wrapped NiGd nanoparticles for coupling methanol electroreforming to H2 production

“…For the purpose of achieving high performance, the design synthesis of advanced TM@C-typed catalysts could be carried out from both carbon shell and metallic core aspects. 32 Heteroatom doping, such as the addition of nitrogen (N), 33 sulfur (S), 34 or phosphorus (P), 35,36 has been proven to be an effective avenue to engineering carbon shells. This method allows for the tuning of the electronic structure and catalytic properties of carbon by regulating the electron interaction between the heteroatoms and adjacent carbon atoms.…”