A highly active and stable hydrogen evolution catalyst based on pyrite-structured cobalt phosphosulfide

Abstract

Rational design and controlled synthesis of hybrid structures comprising multiple components with distinctive functionalities are an intriguing and challenging approach to materials development for important energy applications like electrocatalytic hydrogen production, where there is a great need for cost effective, active and durable catalyst materials to replace the precious platinum. Here we report a structure design and sequential synthesis of a highly active and stable hydrogen evolution electrocatalyst material based on pyrite-structured cobalt phosphosulfide nanoparticles grown on carbon nanotubes. The three synthetic steps in turn render electrical conductivity, catalytic activity and stability to the material. The hybrid material exhibits superior activity for hydrogen evolution, achieving current densities of 10 mA cm−2 and 100 mA cm−2 at overpotentials of 48 mV and 109 mV, respectively. Phosphorus substitution is crucial for the chemical stability and catalytic durability of the material, the molecular origins of which are uncovered by X-ray absorption spectroscopy and computational simulation.

3D Architectures of Quaternary Co‐Ni‐S‐P/Graphene Hybrids as Highly Active and Stable Bifunctional Electrocatalysts for Overall Water Splitting

“…The S 2p spectrum showed two core level peaks at 162.7/163.9 eV in the lower binding energy region and another two peaks at 168.6/169.7 eV in the higher binding energy region. [29] For the P 2p spectrum, a small peak at 129.5 eV represented Co-P binding, [29,30] while two peaks at 133.7 and 134.6 eV were attributed to partial surface oxidation in Co x P resulting from exposure to air. [40] In particular, the two peaks at 168.7 eV in the S 2p spectrum were related to the existence of sulfate in (Co 1−x Ni x )S 2 /G, indicating that (Co 1−x Ni x )S 2 /G is prone to oxidation upon a short exposure to air.…”

“…In addition, it is uneconomical to produce a monofunctional electrocatalyst for each HER and OER, as this raises the manufacturing cost. [2,[29][30][31] Owing to the analogous ionic radius and crystal structure, transition metals (such as Ni and Fe) and P can be substituted in cation and anion sites, respectively. [9][10][11] Recently, transition-metal hydroxides, [7,12] phosphides, [8,[13][14][15][16] nitrides, [17,18] and chalcogenides [19][20][21][22] have been investigated as promising candidates for bifunctional electrocatalysts.…”

Co9S8@N,P-doped porous carbon electrocatalyst using biomass-derived carbon nanodots as a precursor for overall water splitting in alkaline media

“…Co 9 S 8 and a P dopant in carbon structures have been proven to be active species to create catalytic active sites for improving catalysts' activities. 40,41 In elemental mapping analysis, the element N was not detected, possibly owing to its low doping content in Co 9 S 8 @NPC-10, which can be further conrmed by the following high resolution XPS analysis.…”

Nanostructured catalysts for electrochemical water splitting: current state and prospects

“…Jaramillo et al 147 and Liu et al 148 Please do not adjust margins Please do not adjust margins showed an obviously enhanced performance for HER. For example, doping with other element, hybrid with other catalytic materials and composite with carbon materials were investigated.…”