Thermal Shrinkage Engineering Enables Electrocatalysts for Stable Hydrogen Evolution at 2000 mA cm⁻²

Abstract

Constructing highly-active and robust electrodes is vital for the industrialized application of water electrolysis to produce green hydrogen. Nevertheless, the strong disturbance of gas bubbles, especially under ampere-level current densities, would bring about the exfoliation of catalytically active materials and performance deterioration. Herein, a Ru-doped Ni(OH) 2 ultrathin nanosheet array vertically grown on nickel foam with a mechanically-robust interface is first constructed by a facile corrosive engineering strategy. Subsequently, thermal shrinkage engineering inspired by heat shrinkable film is applied to avoid the region away from the interface in ultrathin nanosheets from being damaged by the impact of intensive gas evolution. As a result, the final self-supported electrode has plentiful features including robust binding at the electrocatalyst/support interface and amorphous/crystalline heterophase. These features promote the achievement of superior catalytic activity of a small overpotential of 400 mV and activity retention for over 100 h at 2000 mA cm −2 current density.

Grain Boundary Tailors the Local Chemical Environment on Iridium Surface for Alkaline Electrocatalytic Hydrogen Evolution

“…In this study, we choose the GB-enriched iridium (GBÀ Ir) and alkaline HER as a prototypical catalyst and electrochemical reaction, respectively. Note that the alkaline HER is a fundamental process in many conversion and storage technologies, [23][24][25] and its reaction kinetics are sluggish owing to slow water dissociation and the poor proton supply rate under alkaline conditions, [26][27][28] which have been successfully improved by tailoring the local chemical environment with a tip-effect [29] or synergistic effect. [30] Now, the GBÀ Ir with a low coordination number at the GBs region and a compressive strain mainly distributed along the GB region was successfully constructed using a molten saltassisted strategy.…”

Three-dimensional N, P, and O tri-doped porous carbon for multifunctional electrocatalytic reactions

“…[1][2][3][4] However, the energy efficiency and practical application of these techniques are greatly limited by several important electrocatalytic reactions, such as the hydrogen evolution (HER), oxygen evolution reaction (OER), and oxidation-reduction reaction (ORR). [5][6][7][8] In recent years, the widely accepted benchmark catalysts for these key reactions include Pt/C, RuO 2 , and IrO 2 . Nevertheless, their disadvantages, including exorbitant prices, low reserves, etc., significantly limit their large-scale application.…”

Design strategies of ruthenium‐based materials toward alkaline hydrogen evolution reaction

“…Compared to industrial steam reforming with low-purity hydrogen, electrochemical water splitting in alkaline conditions provides an effective and promising route to produce hydrogen with high purity. [5][6][7] More importantly, such technology can be driven by renewable energy sources. Nevertheless, the reaction kinetics of cathodic hydrogen evolution reaction (HER) in alkaline conditions is relatively sluggish and urgently needs highly active HER catalysts to accelerate the whole process.…”

“…The production of hydrogen through a low‐cost and highly efficient means is a decisive issue and has long been explored. Compared to industrial steam reforming with low‐purity hydrogen, electrochemical water splitting in alkaline conditions provides an effective and promising route to produce hydrogen with high purity 5–7 . More importantly, such technology can be driven by renewable energy sources.…”