Hierarchical CoP/Ni₅P₄/CoP microsheet arrays as a robust pH-universal electrocatalyst for efficient hydrogen generation

Abstract

Exceptional Pt-like electrocatalytic activity was achieved in a sandwich-like catalyst of CoP/Ni5P4/CoP microsheet arrays for pH-universal hydrogen evolution through simply wrapping Ni5P4 nanosheet arrays in CoP nanoparticles.

Construction of CoP/NiCoP Nanotadpoles Heterojunction Interface for Wide pH Hydrogen Evolution Electrocatalysis and Supercapacitor

“…In P 2p spectra (Figure 2d), the binding energy of ≈129 and ≈130 eV could be assigned to the PM (M = Co or Ni) bond in P 2p 3/2 and P 2p 1/2 , and the broad peak at ≈132 eV is attributed to the PO due to the air exposure. [22][23][24] A shift in binding energy is also observed here: the binding energy for PM displays a negative shift of 0.2 and 0.13 eV with respect to that of CoP and NiCoP, respectively, implying an increased electronic density for P. [25] The shifts in binding energy reveal the different chemical states of Co and P in CoP/NiCoP NTs, suggesting the more pronounced electron transfer in CoP/NiCoP due to the interaction between CoP and NiCoP in the closely contacted heterointerface. Besides, both Ni and Co carry a partial positive charge (δ + ), while P carries a partial negative charge (δ − ), implying the formation of hydrogenases-like electronic structure, [26] and M (δ + ) and P(δ − ) act as the hydride-acceptor and proton-acceptor center, benefitting the HER process.…”

Highly Robust Non‐Noble Alkaline Hydrogen‐Evolving Electrocatalyst from Se‐Doped Molybdenum Disulfide Particles on Interwoven CoSe2 Nanowire Arrays

“…Moreover, in order to make a specific comparison with other available catalysts, we utilized a normal electrochemical method to quantify the TOF values depending on the potentials (Figure S11 and S12, Supporting Information), which is an important performance index signifying the intrinsic activity of a catalyst. [ 44,47 ] As shown in Figure S12, Supporting Information, at overpotentials of 100 and 200 mV, the TOF values are calculated to be around 0.47 and 2.91 H 2 s −1 , respectively. Thus, the outstanding catalytic performance of this hybrid catalyst is mainly as a result of the cooperative effects of high intrinsic activity from exposed edge sites, chemical interactions between Se‐MoS 2 and CoSe 2 support, high surface area, and good conductivity from the CoSe 2 and Ni foam support.…”

“…To the best of our knowledge, there are abundant water sources on earth, and there are many other water electrolysis technologies requiring active electrocatalysts to drive the water‐splitting reaction in electrolytes under wide pH ranges. [ 44,47 ] Thus, it is highly desirable to design pH‐universal MoS 2 ‐based catalysts so as to substitute noble catalysts. Surprisingly, this hybrid catalyst still exhibits interesting pH universality as the HER electrocatalysts ( Figure ).…”

Ultrafine Cobalt‐Doped Iron Disulfide Nanoparticles in Ordered Mesoporous Carbon for Efficient Hydrogen Evolution

“…Electrochemical stability was tested by performing CV in the potential region from 0 and −0.5 V at a scan rate of 100 mV s −1 . The theoretical Turnover frequency (TOF) maximum achievable were calculated by assuming that all metal atoms acted as active sites in the catalysis according to Equation …”

“…The theoretical Turnover frequency (TOF) maximum achievable were calculated by assuming that all metal atoms acted as active sites in the catalysis according to Equation 1). [53] TOF ðs À 1 Þ ¼ ðj � AÞ=ð2 � F � nÞ (1) where j (A cm À 2 ) is the measured current density, A (cm 2 ) is the area of the CC electrode, F is the Faraday constant (96485.3 C mol À 1 ), the number 2 means that two electrons are needed to generate one mole of H 2 , and n is the mole number of the metal atoms.…”