Sandwiched NiO/β‐Mo₂C/RGO as Improved Electrocatalyst for Hydrogen Evolution Reaction: Solvothermal‐Assisted Self‐Assembly and Catalytic Mechanism

Abstract

Molybdenum carbide is a cost‐effective alternative to Pt‐group noble metal electrocatalyst for hydrogen evolution reaction (HER), developing a facile strategy to improve the HER activity of molybdenum carbide and understanding the mechanism is of great concern and challenging. Herein, a solvothermal‐assisted self‐assembly procedure of fabricating sandwiched NiO/β‐Mo2C/RGO nanocomposite catalyst was reported. Electrochemical measurements demonstrate that the catalytic activity and durability of β‐Mo2C can be significantly improved in the sandwiched NiO/β‐Mo2C/RGO. Comparative studies between various catalysts such as β‐Mo2C, NiO/β‐Mo2C, β‐Mo2C/RGO, and NiO/β‐Mo2C/RGO have been performed to explore the mechanism underpinning their different catalytic performance. Our results revealed that hybrid of β‐Mo2C and RGO resulted in significant improvement in electrical conductivity, NiO loading modified the electron density on the surface of β‐Mo2C (101) to the electron‐rich state to generate highly active catalytic site. The synergistic effect of RGO and NiO loading would be responsible for the improved electrocatalytic performance of the NiO/β‐Mo2C/RGO catalysts. The strategy developed in this work not only provides a new pathway for improving HER activity of molybdenum carbide but also deepens fundamental understandings on the structure‐reactivity of molybdenum carbide‐based nanocomposite catalysts with higher HER activity.

Polyoxometalate-HKUST-1 composite derived nanostructured Na–Cu–Mo2C catalyst for efficient reverse water gas shift reaction

“…35-0787), respectively. 47 The formation of the Mo 2 C phase after pyrolysis of Mo salts and carbon sources in this temperature range is consistent with previously published works. 48,49 The diffraction peaks at 2θ = 43.3°, 50.4°, and 74.1°can be assigned to the (111), ( 200) and (220) crystal planes of the Cu metallic phase (JCPDS no.…”

Melamine-assisted synthesis of ultrafine Mo2C/Mo2N@N-doped carbon nanofibers for enhanced alkaline hydrogen evolution reaction activity

“…Among these compounds, Mo 2 C and Mo 2 N are outstanding due to their similar d-band density with Pt, good hydrophilia and chemical stability [12][13][14], hence, arising concentrated interests. For example, NiO/β-Mo 2 C/reduced graphene oxide (RGO) [15], α-MoC [16], and Mo 2 C-Mo 3 C 2 [17] were synthesized and employed as electrocatalysts to achieve high HER performance. However, most excellent HER catalytic activity was reported in acid media, where HER starts from a favorable process: 2H 3 O + + 2e − + M → H ad + 2H 2 O [18,19].…”