Enhanced Electrochemical Oxygen Evolution Reaction on Hydrogen Embrittled CoSe Surface

Abstract

In the design of structurally competent electrodes with prolonged lifecycles, a solid understanding of the gaseous hydrogen interaction in a metal lattice is highly desirable. During hydrogen evolution reaction, ingress of H severely affects the physical and mechanical properties of the material causing catastrophic brittle failures (hydrogen embrittlement). In this work, by chronoamperometry technique, an electrode with CoSe catalyst system is intentionally diffused with H to serve as a hydrogen stressed CoSe electrode. Surprisingly this H‐embrittled CoSe electrode exhibits enhanced oxygen evolution reaction (OER) behavior as confirmed by linear sweep voltammetry (LSV), impedance, and Tafel analysis, a cathodic shift of 80 mV at the current density of 10 mA cm−2, impedance analysis reveals half the time of Rct decreasing in the OER on H‐embrittled CoSe than pristine CoSe. The Tafel slope of the H‐embrittled CoSe exhibits of 30 mV, which is relatively lower than the pristine CoSe at OER condition. These results collectively support the enhanced activity of the H‐embrittled CoSe electrode towards OER. Diffusion of hydrogen into metal lattice is confirmed by the high‐resolution transmission electron microscopy (HR‐TEM) fringes analysis, where a 22% decrease Q2 in the lattice distance is revealed by the H‐embrittled CoSe catalyst.

Bird Nest-Like Fe3O4/CoOx Nanosphere Heterojunctions with Amorphous/Crystalline Structure for Enhanced Electrochemical Oxygen Evolution

“…What's more, Zeta potential analysis is helpful in understanding the interaction between different components on the surface of the material. 45,46 As shown in Figure S9, compared with CoO x (−15.5 mV) and Fe 3 O 4 (1.4 mV), the Zeta potential on the surface of the BN-Fe 3 O 4 /CoO x nanosphere is −22.2 mV, indicating the existence of interaction between Fe 3 O 4 and CoO x . Moreover, the higher Zeta potential of the BN-Fe 3 O 4 / CoO x nanosphere indicates that the material has stronger antiaggregation ability, higher dispersibility, and stability, which helps to improve the OER catalytic performance.…”

“…This also proves that the complexes consisting of Fe 2+ ions and the dissociated ligands from Co-CDSAAs are deposited on the surface of Co-CDSAAs. What’s more, Zeta potential analysis is helpful in understanding the interaction between different components on the surface of the material. , As shown in Figure S9, compared with CoO x (−15.5 mV) and Fe 3 O 4 (1.4 mV), the Zeta potential on the surface of the BN-Fe 3 O 4 /CoO x nanosphere is −22.2 mV, indicating the existence of interaction between Fe 3 O 4 and CoO x . Moreover, the higher Zeta potential of the BN-Fe 3 O 4 /CoO x nanosphere indicates that the material has stronger anti-aggregation ability, higher dispersibility, and stability, which helps to improve the OER catalytic performance. , All the above results indicate that BN-Fe 3 O 4 /CoO x nanosphere is an a/c heterostructure, and the electronic regulation at the heterostructure interface can be conducive to excellent catalytic activity in the electrochemical process. , …”

“…The electrocatalytic activities for the OER are examined in a 1.0 M KOH electrolyte at a scan rate of 5 mV s –1 at room temperature. All catalysts were cyclic voltammetry (CV) cycled to a stable state prior to testing, and not corrected by iR -compensation . As shown in Figure a, the BN-Fe 3 O 4 /CoO x nanosphere exhibits a much lower η 10 value (286 mV) than that of Co-CDSAAs (412 mV), CoFe-SUCS (370 mV) and the commercial IrO 2 (434 mV).…”

Strategically designed trimetallic catalyst with minimal Ru addresses both water dissociation and hydride poisoning barriers in alkaline HER

“…[8][9][10][11] However, with the rapidly increasing interest in alkaline water electrolysis, [11][12][13][14] the number of catalysts reported for alkaline OER and HER has also increased in recent years. [15][16][17][18][19] Alkaline water electrolysis has two important advantages over acidic water electrolysis. The rst is the availability of a wide range of OER catalysts from the cheap 3d transition metal row and the ease of making alkaline water by seawater electrolysis.…”