C and N Hybrid Coordination Derived Co–C–N Complex as a Highly Efficient Electrocatalyst for Hydrogen Evolution Reaction

Abstract

Development of an efficient hydrogen evolution reaction (HER) catalyst composed of earth-abundant elements is scientifically and technologically important for the water splitting associated with the conversion and storage of renewable energy. Herein we report a new class of Co-C-N complex bonded carbon (only 0.22 at% Co) for HER with a self-supported and three-dimensional porous structure that shows an unexpected catalytic activity with low overpotential (212 mV at 100 mA cm(-2)) and long-term stability, better than that of most traditional-metal catalysts. Experimental observations in combination with density functional theory calculations reveal that C and N hybrid coordination optimizes the charge distribution and enhances the electron transfer, which synergistically promotes the proton adsorption and reduction kinetics.

Highly active nonprecious metal hydrogen evolution electrocatalyst: ultrafine molybdenum carbide nanoparticles embedded into a 3D nitrogen-implanted carbon matrix

“…Combined with the polarization curves analyzed above, we may safely draw the conclusion that the 3D porous structure not only contributes to the charge transfer but can also produce an enlarged active area and thus contribute favorably to the final hydrogen evolution. These results also reveal that MoCN-3D is among the most active nonprecious HER electrocatalysts in acidic solutions [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][32][33][34][35][36][37][38] (Supplementary Tables S3 and S4). …”

“…Particularly, ultrafine molybdenum carbide nanoparticles embedded in a nitrogen-implanted carbon matrix can work as a promising electrocatalyst because of their hierarchical pores, large surface area, high electrical conductivity and flexibility with the ability to provide continuous charge transportation with minimal diffusion resistance, thus enabling effective electrocatalytic kinetics. 18,19 However, the controllable synthesis of a composite constructed by nanostructured metal carbides coupled with a three-dimensional (3D) carbon matrix remains a great challenge because of the difficulty in achieving uniform carburization and the inevitable coalescence of nanoparticles at a high reaction temperature.…”

Electrocatalysts for hydrogen oxidation and evolution reactions

“…Zhang and co-authors [83] obtained a Co-C-N complex via in situ carbonization of a cobalt ion-absorbed polyaniline (PANI) precursor. An overpotential of 138 mV is required to achieve a current density of 10 mA cm −2 .…”

Straightforward synthesis of nitrogen-doped carbon nanotubes as highly active bifunctional electrocatalysts for full water splitting

“…However, the graphite or carbonaceous materials can be doped by heteroatoms such as nitrogen [24,27], boron [28] or phosphorous [22] to form active metal-free electrocatalysts. Carbonaceous doped materials can be used either as metal-free electrocatalysts [29,30] or as catalyst supports [31] for active metal nanoparticles to get the advantage of synergistic catalytic activity. The chemical and electronic properties of these doped materials can significantly alter their OER and HER performance because of the induced changes in the local charge density and asymmetry spin density of the carbon lattice [32].…”