Progress and Challenge of Amorphous Catalysts for Electrochemical Water Splitting

Abstract

Electrochemical water splitting has been regarded a promising technology to provide a mobile and sustainable energy supply in the form of hydrogen fuel. The key to further development towards industrial application lies in high-efficiency and low-cost electrocatalysts. In recent years, new attention has been paid to amorphous electrocatalysts, which have short-range atomic ordering instead of translational periodicity. The structural flexibility and rich defects associated with amorphous catalyst materials offer enormous opportunities for electrochemical water splitting. In this Perspective, we elaborate on recent studies of amorphous electrocatalysts for electrochemical water splitting. Our discussion covers the diverse amorphization strategies, the positive role of structural flexibility and defects in enriching active sites, as well as challenges in the characterization of local geometry and in improving electrochemical stability. Finally, we conclude with prospective remarks for future development in amorphous electrocatalyst materials for electrochemical water splitting.

Hierarchical Structure of CuO Nanowires Decorated with Ni(OH)2 Supported on Cu Foam for Hydrogen Production via Urea Electrocatalysis

“…[ 2 ] However, large overpotentials are required to drive water splitting in practical applications, mainly due to the kinetically unfavorable rate of the anodic reaction, that is, the oxygen evolution reaction (OER). [ 3 ] Compared with the other half‐reaction (hydrogen evolution reaction (HER)), OER, which involves four‐electron‐transfer processes to form oxygen–oxygen bonds, is considered to be the bottleneck for the overall water splitting. [ 4 ] To overcome this drawback, replacing water molecules with more oxidizable molecules, such as urea, ethanol, amine, and hydrazine, paves another route to energy‐saving hydrogen production.…”

Recent Progress on Structurally Ordered Materials for Electrocatalysis

“…In addition to the long‐rang ordering, materials with short‐range ordering, namely amorphous structure, also show some advantages such as rich dandling bonds and more exposed surface active sites. [ 137 ] The in situ‐formed (oxy)hydroxides during the electrochemical reaction usually exhibit low crystallinity. Recently, to highlight the advantageous role of transition (oxy)hydroxides with low crystallinity in electrocatalysis, Ye et al.…”

“…Thus, the rational design of long‐range ordering (with crystalline structure), short‐range ordering (with amorphous structure) and crystalline‐amorphous materials needs more insights into the material properties and in‐depth understanding of the structure‐activity relationship. [ 137a,140 ]…”

Three‐dimensional Porous Co Doped VN Nanosheet Arrays as Cathode Electrode for Alkaline Water Electrolysis

“…Water electrolysis is considered as the best hydrogen production technology because of its safety, environmental friendliness, recycling and other advantages. [1,2] At present, the alkaline liquid water electrolysis and solid polymer water electrolysis including acid proton exchange membrane technology and alkaline anion exchange membrane (AEM) technology have realized practical application at low temperatures. [3] AEM water electrolysis technology effectively solves the adverse effects caused by the reaction of traditional alkaline solution electrolyte and gases.…”