Nanoporous Graphene with Single‐Atom Nickel Dopants: An Efficient and Stable Catalyst for Electrochemical Hydrogen Production

Abstract

Single-atom nickel dopants anchored to three-dimensional nanoporous graphene can be used as catalysts of the hydrogen evolution reaction (HER) in acidic solutions. In contrast to conventional nickel-based catalysts and graphene, this material shows superior HER catalysis with a low overpotential of approximately 50 mV and a Tafel slope of 45 mV dec(-1) in 0.5 M H2SO4 solution, together with excellent cycling stability. Experimental and theoretical investigations suggest that the unusual catalytic performance of this catalyst is due to sp-d orbital charge transfer between the Ni dopants and the surrounding carbon atoms. The resultant local structure with empty C-Ni hybrid orbitals is catalytically active and electrochemically stable.

Flexible Honeycombed Nanoporous/Glassy Hybrid for Efficient Electrocatalytic Hydrogen Generation

“…The scanning transmission electron microscopy (STEM) elemental mapping shown in Figure 3b reveals that the edges are enriched with Pt, although the MG precursor only contains 3 at% Pt. [36] The Pt 4f spectrum consists of two peaks for metallic Pt with binding energy of 71.21 (Pt 4f 7/2 ) and 74.56 eV (Pt 4f 5/2 ), respectively. The obvious Pt aggregation on the honeycombed surface structure is due to the phase segregation of Pt from Ni during dealloying.…”

3D Nanoporous Metal Phosphides toward High‐Efficiency Electrochemical Hydrogen Production

“…Consequently, the free-standing np-Co 2 P catalyst possesses outstanding electrocatalysis toward HER in both acidic and basic solutions, which is comparable to the commercial Pt/C catalyst and presents high promise as a Pt-free catalyst for electrochemical hydrogen production. [22][23][24][25][26][27][28] The catalytic stability of np-Co 2 P was evaluated by prolonged electrochemical testing at constant potentials. As shown in Figure S11 of the Supporting Information, the current densities of np-Co 2 P remain stable in both acidic and basic solutions for a long-time operation of over 50 000 s. After the long time testing, the 3D nanoporous structure is well retained without visible changes in pore sizes and morphology ( Figure S11, Supporting Information), corroborating the excellent electrochemical stability of np-Co 2 P in both acidic and basic environments.…”

Combining photocatalytic hydrogen generation and capsule storage in graphene based sandwich structures

“…Efficient electron–hole separation could be achieved through ultrafast charge transferring between GR–C 3 N 4 layers despite of their weak van der Waals interaction, which has been experimentally observed in vertically stacked transition-metal dichalcogenide heterostructure bilayers with weak van der Waals interaction252627. Moreover, functional groups on GR, including hydroxyl and epoxy, doped heteroatoms, and defects, provide good active sites for water decomposition202829303132. Our theoretical and experimental works demonstrate that parts of photo-generated electrons in carbon nitrides are collected at nitrogen positions3334, providing ideal reductive sites for hydrogen generation35.…”