Manganese and selenium co-doped CeO₂@Co₃O₄ porous core–shell nanospheres for enhanced oxygen evolution reactions

Abstract

As one of the semi-reactions of water splitting, electrocatalytic oxygen evolution reaction (OER) is a key process to generate sustainable energy. Co-based spinel oxides are deemed as promising OER electrocatalysts,...

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

“…When the reaction was extended to 3–6 h, the CoFe-SUCS structure remained almost the same morphology of the sea urchin-like hollow core–shell nanosphere, which is completely different from that of Co-CDSAAs (Figures f–i and S2f–i). Fourier transform infrared (FT-IR) spectroscopy (Figure S3) revealed that their characteristic absorption peaks are almost the same except for the infrared absorption peaks in the fingerprint region, which is different from our report. − This may be the reason for the different morphologies of the CoFe-SUCS and Co-CDSAAs.…”

“…Considering these points, with the inspiration of our previous work, − we report a strategy of cation exchange followed by Ar/H 2 annealing to construct a bird nest-like bimetallic OER electrocatalyst with a/c heterostructure nanosphere (BN-Fe 3 O 4 /CoO x ). In this design, cobalt coordination-driven self-assembled aggregates (Co-CDSAAs) are still the precursor as we used before .…”

Selenium-enriched hollow NiCo2O4/NiO heterostructured nanocages as an efficient electrocatalyst for oxygen evolution reaction

“…The EIS serves as an effective indicator, offering insights into both the rate of electron transfer and the resistance between the electrode/electrolyte interfaces. 59 One of the key factors is charge transfer resistance ( R ct ), which reflects the kinetics of the electrocatalysts towards the OER activity. The 5 wt% Se–NiCo 2 O 4 /NiO electrocatalyst reveals 7.65 Ω charge transfer resistance, which is smallest in comparison with those obtained for 10 wt% Se–NiCo 2 O 4 /NiO (9.51 Ω), NiCo 2 O 4 /NiO (14.2 Ω), 5 wt% Se–NiCo–LDH (10.6 Ω), 10 wt% Se–NiCo–LDH (11.6 Ω) and NiCo–LDH (15.4 Ω).…”

“…The EIS serves as an effective indicator, offering insights into both the rate of electron transfer and the resistance between the electrode/electrolyte interfaces. 59 One of the key factors is charge transfer resistance (R ct ), which reflects the kinetics of the electrocatalysts towards the OER activity. These findings suggest a substantial improvement in the electrical conductivity of materials after the introduction of 5 wt% Se, leading to greater reaction kinetics.…”

Highly Active Cobalt–Copper–Selenide Electrocatalysts for Solar-Driven Oxygen Evolution Reaction: An Electrochemical Activation Energy Aspect

“…Notably, the surface of CoCuSe was reconstructed after OER, which transformed nanofiber to nanosheet. Based on previous studies, it is known that transition metal selenides are transformed into oxyhydroxide species, which are active species of OER, due to surface reconstruction during OER. ,,, The ratio of Cu 1+ and Cu 2+ (Cu 1+ /Cu 2+ ) was changed from 1.06 (before the OER) to 0.98 (after OER). Also, the ratios of Co 3+ and Co 2+ (Co 3+ /Co 2+ ) were 0.87 (before OER) and 1.85 (after OER), suggesting the formation of active oxyhydroxide species due to surface reconstruction after OER. ,, Interestingly, noticeable variations were observed in the XPS spectrum of O 1s …”