Manifesting p-d Orbital Hybridization Through Strategic D-Band Engineering: A Pathway to Boosted Bifunctional HER/OER Electrochemical Performance in Self-Templated Co-SnO2 Grown Over Co-SnS2 Nanosheets.
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引用次数: 0
Abstract
In this study, Co-doped SnO2 is synthesized atop the hexagonal CoS template (CoSS) via direct air calcination of as-synthesized Co-doped SnS2 (CoS) nanosheets. The structural evolution facilitated the emergence of Co2+ and Co3+ states, complemented by surface-adsorbed sulfur oxyanions (SO42-, HSO3-, SO32-). CoSS deposited over carbon cloth (CoSS/CC) exhibited superior bifunctional HER and OER, demonstrating higher stability and efficiency than their CoS/CC counterparts. Notably, CoSS/CC||CoSS/CC shows the overall water splitting at a minimum cell voltage of 1.5 V, significantly lower than CoS/CC||CoS/CC. Mechanistically, the Co3+ states serve as catalytically active sites that enhance OER, while the synergistic interaction between Co3+ and the sulfur oxyanions promotes HER activities. Density functional theory (DFT) calculations revealed an upshifted d-band centre (ɛd) and enhanced metal-oxygen covalency (Δ) in CoSS, with superior charge transfer and p-d hybridization. ATR-FTIR, Raman, and XPS investigations confirmed surface reconstruction of CoSS/CC electrodes with enhanced electrical conductivity. It is related that a highly strained system of VO-CoSS has more unfilled electronic states near the Fermi level (ɛF) to facilitate a stable interaction with HER/OER intermediates. Overall, this study underscores the superior bifunctional electrocatalytic efficiency of CoSS/CC over CoS/CC, establishing it as a promising candidate for efficient overall water splitting.
Small MethodsMaterials Science-General Materials Science
CiteScore
17.40
自引率
1.60%
发文量
347
期刊介绍:
Small Methods is a multidisciplinary journal that publishes groundbreaking research on methods relevant to nano- and microscale research. It welcomes contributions from the fields of materials science, biomedical science, chemistry, and physics, showcasing the latest advancements in experimental techniques.
With a notable 2022 Impact Factor of 12.4 (Journal Citation Reports, Clarivate Analytics, 2023), Small Methods is recognized for its significant impact on the scientific community.
The online ISSN for Small Methods is 2366-9608.