Heterostructuring Mesoporous 2D Iridium Nanosheets with Amorphous Nickel Boron Oxide Layers to Improve Electrolytic Water Splitting

Abstract

Abstract2D heterostructures exhibit a considerable potential in electrolytic water splitting due to their high specific surface areas, tunable electronic properties, and diverse hybrid compositions. However, the fabrication of well‐defined 2D mesoporous amorphous‐crystalline heterostructures with highly active heterointerfaces remains challenging. Herein, an efficient 2D heterostructure consisting of amorphous nickel boron oxide (Ni‐Bi) and crystalline mesoporous iridium (meso‐Ir) is designed for water splitting, referred to as Ni‐Bi/meso‐Ir. Benefiting from well‐defined 2D heterostructures and strong interfacial coupling, the resulting mesoporous dual‐phase Ni‐Bi/meso‐Ir possesses abundant catalytically active heterointerfaces and boosts the exposure of active sites, compared to their crystalline and amorphous mono‐counterparts. The electronic state of the iridium sites is tuned favorably by hybridizing with Ni‐Bi layers. Consequently, the Ni‐Bi/meso‐Ir heterostructures show superior and stable electrochemical performance toward both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in an alkaline electrolyte.

White Light Generating Molecular Materials: Correlation Between the Amorphous/Crystalline Structure and Nonlinear Optical Properties

“…[1][2][3] Examples for recent developments include supercapacitors, electrolytic water splitting, and battery materials. [4][5][6] The amorphous materials show widely superior properties compared to their crystalline counterparts in their respective applications. The key for understanding and enhancing any desirable features, in general, is understanding the microscopic structure, or rather, the absence thereof in such materials.…”

“…Applications range from amorphous silicon in photovoltaics to metal‐based amorphous alloys for data storage or highly elastic metallic glasses [1–3] . Examples for recent developments include supercapacitors, electrolytic water splitting, and battery materials [4–6] . The amorphous materials show widely superior properties compared to their crystalline counterparts in their respective applications.…”

Composition Engineering of Amorphous Nickel Boride Nanoarchitectures Enabling Highly Efficient Electrosynthesis of Hydrogen Peroxide

“…The purpose of choosing nickel borides here is owing to their tunable composition, high intrinsic conductivity, multiple functions as well as the viable 2e − ORR pathway. [29][30][31][32][33][34][35][36] The X-ray absorption spectra (XAS), in situ Raman spectra, transient photo voltage (TPV) measurements coupled with density functional theory (DFT) calculations unveiled that the variation of atomic ratio leads to the distinct electronic structure of nickel borides, which then alters both the adsorption free energy and adsorption model of active Ni site to the *OOH intermediate as well as the surface charge-transfer kinetics on their surface. The optimal amorphous NiB 2 nanoarchitectures exhibited the best H 2 O 2 selectivity up to 99% at 0.4 V and more than 93% in a wide potential range from 0.2 to 0.6 V vs reversible hydrogen electrode (RHE).…”

Highly Efficient and Stable Iridium Oxygen Evolution Reaction Electrocatalysts Based on Porous Nickel Nanotube Template Enabling Tandem Devices with Solar‐to‐Hydrogen Conversion Efficiency Exceeding 10%

“…[17,18] Nanostructure fabrication is a notable approach for reducing Ir use without losing catalytic activity. [19][20][21][22] For example, Tan et al used IrO x catalysts in the form of nanoparticles to achieve high catalytic performance with a small amount of Ir: a potential, E j=10 , of 1.48 V at an operating current of 10 mA cm −2 , and a mass activity of 1400 A g Ir −1 . [19] In a study by Böhm et al, a matrix consisting of porous antimony-doped, tin-oxide microparticles embedded with IrO x nanoparticles exhibited a potential of 1.47 V at 1 mA cm −2 , which was ≈50 mV lower than that of the Ir nanoparticle catalyst.…”

“…Nanostructure fabrication is a notable approach for reducing Ir use without losing catalytic activity. [ 19 , 20 , 21 , 22 ] For example, Tan et al. used IrO x catalysts in the form of nanoparticles to achieve high catalytic performance with a small amount of Ir: a potential, E j =10 , of 1.48 V at an operating current of 10 mA cm −2 , and a mass activity of 1400 A g Ir −1 .…”