Self‐Supported Electrocatalysts for Practical Water Electrolysis

Abstract

Over the years, significant advances have been made to boost the efficiency of water splitting by carefully designing economic electrocatalysts with augmented conductivity, more accessible active sites, and high intrinsic activity in laboratory test conditions. However, it remains a challenge to develop earth‐abundant catalysts that can satisfy the demands of practical water electrolysis, that is, outstanding all‐pH electrolyte capacity, direct seawater splitting ability, exceptional performance for overall water splitting, superior large‐current‐density activity, and robust long‐term durability. In this context, considering the features of increased active species loading, rapid charge, and mass transfer, a strong affinity between catalytic components and substrates, easily‐controlled wettability, as well as, enhanced bifunctional performance, the self‐supported electrocatalysts are presently projected to be the most suitable contenders for practical massive scale hydrogen generation. In this review, a comprehensive introduction to the design and fabrication of self‐supported electrocatalysts with an emphasis on the design of deposited nanostructured catalysts, the selection of self‐supported substrates, and various fabrication methods are provided. Thereafter, the recent development of promising self‐supported electrocatalysts for practical applications is reviewed from the aforementioned aspects. Finally, a brief conclusion is delivered and the challenges and perspectives relating to promotion of self‐supported electrocatalysts for sustainable large‐scale production of hydrogen are discussed.

Sequential Phase Conversion‐Induced Phosphides Heteronanorod Arrays for Superior Hydrogen Evolution Performance to Pt in Wide pH Media

“…In order to determine the active sites of the active Ni 2 P-Ni 12 P 5 , we conducted the in situ Raman characterization on Ni 2 P-Ni 12 P 5 @Ni 3 S 2 /NF in neutral media, which was specially selected because that electrocatalysts normally exhibit the most unfavorable HER activity under neutral environment. [57,58] As seen in Figure 5a, at the potential of open circuit potential (OCP), only a band located at 279 cm −1 can be identified, which can be ascribed to the presence of P-O, [59] being in agreement with the XPS results. With the beginning and increase of the applied potential, the band positioned at 840 cm −1 representing the hydrated nickel (Ni-H ad ) vibration, while the two bands at the region between 400 and 580 cm −1 corresponding to the Ni-O vibration in hydroxylated Ni (Ni-OH ad ) emerged and intensified simultaneously, [60][61][62] implying that the Ni atoms in the heterophasic Ni 2 P-Ni 12 P 5 would be the real active sites for the HER, including the water dissociation and hydrogen recombination steps.…”

The Pivotal Role of s‐, p‐, and f‐Block Metals in Water Electrolysis: Status Quo and Perspectives

“…[2] Among them, water splitting is of particular interest because of its readily coupling with renewable wind and solar power to produce hydrogen fuel with high purity. [3,4] However, the thermodynamically uphill and sluggish kinetics of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) of water splitting inevitably degrades the overall energy efficiency. [5] To address this issue, highly efficient electrocatalysts are indispensable to lower the energy barrier and to accelerate the OER and HER reaction.…”

High Selectivity Electrocatalysts for Oxygen Evolution Reaction and Anti-Chlorine Corrosion Strategies in Seawater Splitting

“…To address these problems, many "green" technologies have been investigated to deploy renewable and environmentally friendly energy, such as solar, tidal, and wind energies [1][2][3][4]. Hydrogen is considered to be an ideal clean energy source for the future, and it can be produced by many methods, such as fossil fuel extraction, methane reorganization, photocatalytic water decomposition, and so on [5]. Among these, electrolytic water splitting provides an effective way to generate "green" hydrogen in addition to the above-mentioned intermittent renewable energy sources [6][7][8][9].…”