{"title":"Unveiling the performance of ultrathin bimetallic CoxNi1−x(OH)2 nanosheets for pseudocapacitors and oxygen evolution reaction","authors":"Pallavi Bhaktapralhad Jagdale, Sayali Ashok Patil, Arupjyoti Pathak, Mukaddar Sk, Ranjit Thapa, Amanda Sfeir, Sebastien Royer, Akshaya Kumar Samal, Manav Saxena","doi":"10.1039/d4ta06846g","DOIUrl":null,"url":null,"abstract":"The rational design of highly efficient and stable electrodes is necessary for energy storage and electrocatalysis. Herein, we developed a nanometre thin bimetallic ultrathin Co<small><sub><em>x</em></sub></small>Ni<small><sub>1−<em>x</em></sub></small>(OH)<small><sub>2</sub></small> nanosheet with a large lateral size by the ionic layer epitaxy (ILE) technique as an efficient bifunctional electrode material for pseudocapacitors and the oxygen evolution reaction. Its electrochemical performance was readily tuned by controlling the Co/Ni ratio. The nanosheet with a 1 : 3 Co : Ni ratio (termed Co<small><sub>1</sub></small>Ni<small><sub>3</sub></small>-NS) showed an excellent volumetric (areal) capacitance of 3783 F cm<small><sup>−3</sup></small> (3 mF cm<small><sup>−2</sup></small>) at 0.3 mA cm<small><sup>−2</sup></small> with 336 mW h cm<small><sup>−3</sup></small> energy density at 256 W cm<small><sup>−3</sup></small> power density and excellent stability, substantially outperforming other monometallic and bimetallic NSs. Moreover, as an electrocatalyst, Co<small><sub>1</sub></small>Ni<small><sub>3</sub></small>-NS delivered a lower overpotential (<em>η</em><small><sub>10</sub></small> = 318 mV) and Tafel slope (61 mV dec<small><sup>−1</sup></small>) in an alkaline environment. <em>In situ</em> Raman spectroscopy was employed to demonstrate the dynamic structural evolution of the catalyst during the OER process. Furthermore, DFT investigations further revealed that Co<small><sub>1</sub></small>Ni<small><sub>3</sub></small>-NS is a promising electrode with higher quantum capacitance and lower overpotential compared to other Co/Ni ratios. These findings pave a new way for controlled synthesis of highly efficient, bimetallic, and bifunctional electrode materials for pseudocapacitors and the OER.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"232 1","pages":""},"PeriodicalIF":10.7000,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Materials Chemistry A","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1039/d4ta06846g","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The rational design of highly efficient and stable electrodes is necessary for energy storage and electrocatalysis. Herein, we developed a nanometre thin bimetallic ultrathin CoxNi1−x(OH)2 nanosheet with a large lateral size by the ionic layer epitaxy (ILE) technique as an efficient bifunctional electrode material for pseudocapacitors and the oxygen evolution reaction. Its electrochemical performance was readily tuned by controlling the Co/Ni ratio. The nanosheet with a 1 : 3 Co : Ni ratio (termed Co1Ni3-NS) showed an excellent volumetric (areal) capacitance of 3783 F cm−3 (3 mF cm−2) at 0.3 mA cm−2 with 336 mW h cm−3 energy density at 256 W cm−3 power density and excellent stability, substantially outperforming other monometallic and bimetallic NSs. Moreover, as an electrocatalyst, Co1Ni3-NS delivered a lower overpotential (η10 = 318 mV) and Tafel slope (61 mV dec−1) in an alkaline environment. In situ Raman spectroscopy was employed to demonstrate the dynamic structural evolution of the catalyst during the OER process. Furthermore, DFT investigations further revealed that Co1Ni3-NS is a promising electrode with higher quantum capacitance and lower overpotential compared to other Co/Ni ratios. These findings pave a new way for controlled synthesis of highly efficient, bimetallic, and bifunctional electrode materials for pseudocapacitors and the OER.
期刊介绍:
The Journal of Materials Chemistry A, B & C covers a wide range of high-quality studies in the field of materials chemistry, with each section focusing on specific applications of the materials studied. Journal of Materials Chemistry A emphasizes applications in energy and sustainability, including topics such as artificial photosynthesis, batteries, and fuel cells. Journal of Materials Chemistry B focuses on applications in biology and medicine, while Journal of Materials Chemistry C covers applications in optical, magnetic, and electronic devices. Example topic areas within the scope of Journal of Materials Chemistry A include catalysis, green/sustainable materials, sensors, and water treatment, among others.