In Situ Coupling of CoP Polyhedrons and Carbon Nanotubes as Highly Efficient Hydrogen Evolution Reaction Electrocatalyst

Abstract

Hydrogen evolution reaction (HER) from water electrolysis is an attractive technique developed in recent years for cost-effective clean energy. Although considerable efforts have been paid to create efficient catalysts for HER, the development of an affordable HER catalyst with superior performance under mild conditions is still highly desired. In this work, metal-organic frameworks (MOFs)-templated strategy is proposed for in situ coupling of cobalt phosphide (CoP) polyhedrons nanoparticles and carbon nanotubes (CNTs). Due to the synergistic catalytic effect between CoP polyhedrons and CNTs, the as-prepared CoP-CNTs hybrids show excellent HER performance. The resultant CoP-CNTs demonstrate excellent HER activity in 0.5 m H SO with Tafel slope of 52 mV dec , small onset overpotential of ≈64 mV, and a low overpotential of ≈139 mV at 10 mA cm . Additionally, the catalyst also manifests superior durability in acid media. Considering the structure diversity of MOFs, the strategy presented here can be extended for synthesizing other well-defined metal phosphides-CNTs hybrids, which may be used in the fields of catalysis, energy conversion and storage.

Tungsten‐Doped CoP Nanoneedle Arrays Grown on Carbon Cloth as Efficient Bifunctional Electrocatalysts for Overall Water Splitting

“…Non-noble metal phosphides, [5] chalcogenides, [6] carbides, [7] nitrides [8] have been explored as electrocatalysts for HER in acidic media and metal oxides [9] or hydroxide [10] are widely investigated as OER catalysts in basic media. Although these HER and OER electrocatalysts often function well in acidic or alkaline solutions, respectively, it is difficult to couple HER and OER catalysts in an integrated electrolyzer in the same electrolyte with good overall water splitting performance because of the incompatibility between stability and activity.…”

Phase‐Controlled Cobalt Phosphide Nanoparticles Coupled with N, P, S Co‐Doped Hollow Carbon Polyhedrons as Efficient Catalysts for Both Alkaline and Acidic Hydrogen Evolution

“…The overpotentials of 178, 227, 257, 285, and 407 mV are required to deliver a current density of 10 mA cm −2 , corresponding to CoP@NPS‐C, Co 2 P@NPS‐C, CoP@NC, Co@NC, and NPS‐C, respectively, thus implying the good HER electrocatalytic properties of Co x P@NPS‐C in acidic medium. Co x P@NPS‐C can also compete favorably with some reported HER electrocatalysts under acidic medium (Table S5, Supporting Information), including CoP‐CNTs (139 mV), urchin‐like CoP (105 mV), Ni 2 P/CNT (124 mV), FeP‐CS (112 mV), and MoP (135 mV) . Moreover, as shown in Figure b, the Co x P@NPS‐C catalysts have a small Tafel slope of 60.2 mV dec −1 , which is lower than that of Co@NC (108.7 mV dec −1 ), NPS‐C (143.3 mV dec −1 ), CoP@NC (105.8 mV dec −1 ), Co 2 P@NPS‐C (95.4 mV dec −1 ), and CoP@NPS‐C (78.5 mV dec −1 ), thus implying its more favorable kinetics for HER under acidic medium.…”

Cobalt‐Based MOF‐Derived CoP/Hierarchical Porous Carbon (HPC) Composites as Robust Catalyst for Efficient Dehydrogenation of Ammonia‐Borane

“…Figure d shows the P 2p peaks appeared at 130.5, 129.5, and 134.6 eV, corresponding the binding energies of P 2p 1/2 , P 2p 3/2 in Co−P, and oxidized P species, respectively (Figure d). Compared with the binding energies of phosphorus species (130.2 eV) and Co metal (778.1 eV), the binding energy of P 2p 3/2 exhibited a negative shift while Co 2p 3/2 showed a positive shift, respectively, implying an electron transfer of CoP@HPC−T from Co to P …”