A core@shell hollow heterostructure of Co3O4 and Co3S4: an efficient oxygen evolution catalyst. (23rd September 2019)

• Record Type: Journal Article
• Authors: Mahala, Chavi; Sharma, Mamta Devi; Basu, Mrinmoyee
• Is Part Of: New journal of chemistry. Volume 43:Number 39(2019)
• Page Start: 15768
• Page End: 15776
• Publication Date: 2019-09-23
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c9nj03623g
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : A hollow core@shell nanostructure of Co3 O4 and Co3 S4 helps to enhance the electrocatalytic activity for the OER. Abstract : To avoid a massive energy crisis in the near future, it becomes urgent to develop efficient catalysts for the oxygen evolution reaction (OER) in water splitting. For this purpose, a two dimensional (2D) heterostructure of Co3 O4 and Co3 S4 is prepared following a simple multi-step method that incorporates a wet-chemical technique followed by a hydrothermal method. Initially, 2D sheets of Co3 O4 are synthesized using the wet-chemical method followed by calcination. Finally, the heterostructure Co3 O4 @Co3 S4 is fabricated from the Co3 O4 sheets following a simple Kirkendall process through sulfurization for electrochemical application. Slow anion exchange leads to development of a hollow core@shell 2D Co3 O4 @Co3 S4 heterostructure. After sulfidation, the heterostructure of 2D sheets shows excellent conductivity and improved electrocatalytic activity for the OER compared to bare Co3 O4 . The best-obtained Co3 O4 @Co3 S4 can produce a 20 mA cm −2 current density upon application of 1.647 V vs. RHE, which is ∼100 mV lower compared to bare Co3 O4 . Sulfidation of Co3 O4 leads to the formation of hollow heterostructures with a ∼2.8 times higher electrochemically active surface area. Co3 O4 @Co3 S4 is very stable, and it can produce an unaltered current density up to 1000 continuous cycles in the OER.