Structural and Componential Engineering of Co₂P&CoP@N–C Nanoarrays for Energy-Efficient Hydrogen Production from Water Electrolysis

Abstract

The development of electrocatalysts for efficient water splitting is a pivotal and challenging task. Transition-metal phosphides (TMPs) have been known as one of the most promising candidates for the efficient hydrogen evolution reaction (HER) due to their favorable intrinsic reactivity. However, structural engineering related to the gas bubbles evolution and tiny regulation of components concerned with the electronic structure remained as a significant challenge that requires further optimization. Herein, the nanoarrays (NAs) composed of ultrasmall Co2P and CoP nanoparticle-embedded N-doped carbon matrix (Co2P&CoP@N–C) are prepared and demonstrated an overpotential of 62.8 ± 4.7 mV at 10 mA cm–2 in 1.0 M KOH. The nanoarray-structured electrocatalyst revealed the superaerophobicity and facilitates the detachment of the in situ formed hydrogen gas bubbles, ensuring abundant catalytic sites and electrode–electrolyte interface for the mass transfer process. The amount of P doping modulated the local electron density around Co and P atoms, which attains a favorable compromise to afford sufficient electrons for the electrocatalysis and inhibit the negative influence of H2 desorption. Significantly, the lowered overpotential induced by the electrocatalyst surface architecture is much stronger than that of the component content and promotes the electrocatalytic activity.

One-Step Electrodeposition of NiMoP/NF as an Efficient and Cost-Effective Cathodic Electrocatalyst for Alkaline Water Electrolysis

“…Although many studies have been conducted on decreasing the doping amount of rare and precious metals like Pt, Pd, and Ir, and the properties of these materials also have shown excellent performance, − the nonrenewable and scarce precious metals are still difficult to produce and use on a large scale. Transition metals, such as Ni, Mo, Fe, Co, and so on, have rich content, the alloy formed by each other, − and the transition metal-based compounds formed with P, B, S, N, and other elements have excellent electrolytic water hydrogen evolution performance − and will eventually become a substitute for precious metals . Among the transition metal-based compounds, numerous studies have proved that transition metal-based phosphates (TMPs) have excellent activity, abundant active sites, and long-term stability .…”

“…All potentials were converted to the potential relative to the reversible hydrogen standard electrode (RHE) and calculated by the following equation Linear sweep voltammetry (LSV) was used to exhibit the hydrogen evolution reaction (HER) performance from 0.1 to −0.4 V vs RHE at a scanning rate of 2 mV s −1 and the potential was corrected by iR compensation. The cyclic voltammetry (CV) curves were measured at different sweep speeds(20,40, 60, 80, 100 mV s −1 ), and the tests were conducted in the non-Faraday range of 0.10−0.20 V vs RHE. Electrochemical impedance spectroscopy (EIS) was tested in the range of 0.1 Hz to 100 kHz at a hydrogen evolution potential of −0.15 V vs RHE.…”

Modulating the Electronic Structure of Co2P/NiWO4 by Interfacial Engineering for Enhanced Seawater Electrolysis

“…18,19 Therefore, enormous work has been carried out to search for cheap and abundant catalysts. Among various candidates, transition metal compound-based materials, including sulfides, 20 carbides, 21 selenides, 22 nitrides, 23 hydroxides, 24 and phosphides, 25 have emerged as an important class of non-noble metal catalysts for seawater electrolysis due to their low-cost and tunable electronic structure. Recently, cobalt phosphide, because of its unique features such as high intrinsic catalytic activity and tunable structure, has attracted a lot of attention for use in electrocatalytic seawater splitting.…”

“…Amid the development of seawater electrolysis, the noble metals have demonstrated their high potential, but their high price and limited reserve greatly hinder their wide applications. , Therefore, enormous work has been carried out to search for cheap and abundant catalysts. Among various candidates, transition metal compound-based materials, including sulfides, carbides, selenides, nitrides, hydroxides, and phosphides, have emerged as an important class of non-noble metal catalysts for seawater electrolysis due to their low-cost and tunable electronic structure. Recently, cobalt phosphide, because of its unique features such as high intrinsic catalytic activity and tunable structure, has attracted a lot of attention for use in electrocatalytic seawater splitting. , Nevertheless, cobalt phosphide is prone to deactivation due to poisoning effects caused by the complex ionic environment in seawater, resulting in undesirable performance .…”

Electronegativity Enhanced Strong Metal–Support Interaction in Ru@F–Ni3N for Enhanced Alkaline Hydrogen Evolution

“…Rational design of low-cost and high-efficient catalysts and exploring effective strategies for optimizing their intrinsic activity are of significant importance for pure and clean hydrogen production via water electrolysis. , For now, the first-rank electrocatalytic materials are still noble metals and their related compounds, such as Pt, Ir, and Ru, , but their application is severely impeded by the scarcity and exorbitant price. , One of the pragmatic strategies to overcome these deficiencies in noble metal-based electrocatalysts is to reduce the size of bulk counterpart into corresponding nanoparticles (NPs) or even single-atom catalysts (SACs), which can remarkably optimize the electronic structure of active centers, promote the content of catalytic active sites, and also reduce their consumption. − However, some obstacles such as the stability of anchored SACs at high current density and enhancing the catalytic activity with ultralow SAC loading still need to be settled . Also, there are few methods to modulate the strong metal–support interaction (SMSI) between the support [including metal (hydro)­oxides, , phosphides, and carbon materials , ] and the loaded SACs, which has a vital influence on the intrinsic catalytic activity of SACs .…”