A facile method for reduced CoFe2O4 nanosheets with rich oxygen vacancies for efficient oxygen evolution reaction. (21st September 2017)

• Record Type: Journal Article
• Authors: Yan, Kai-Li; Shang, Xiao; Liu, Zi-Zhang; Dong, Bin; Lu, Shan-Shan; Chi, Jing-Qi; Gao, Wen-Kun; Chai, Yong-Ming; Liu, Chen-Guang
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 38(2017)
• Page Start: 24150
• Page End: 24158
• Publication Date: 2017-09-21
• Subjects: Oxygen vacancy -- Binary metal oxides -- Electrocatalysts -- Oxygen evolution reaction -- NaBH4 reduction; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.07.165
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The efficiency of electrochemical water splitting is greatly hindered by the thermodynamic uphill reaction of oxygen evolution reaction (OER). Thus, it is important to synthesize an active OER electrocatalysts with abundant active sites, favorable conductivity and good durability. Herein, a facile reduction method using NaBH4 as readily available reductant has been developed to fabricate the reduced CoFe2 O4 nanosheets (NS). The obtained reduced CoFe2 O4 NS are rich in oxygen deficient sites, leading to more active sites as well as the enhanced conductivity than the pristine CoFe2 O4 hollow nanosphere, which reaches the current density of 10 mA cm −2 at the overpotential of 320 mV in 1 M KOH. Meanwhile, CoFe2 O4 samples with three different morphology nanostructures including hollow nanospheres, bulk and nanoparticles have been provided to study the effect of different morphology on NaBH4 reduction efficiency. As expected, after NaBH4 reduction, CoFe2 O4 hollow nanosphere with relatively higher surface area exhibits most obvious improvement for OER activity and also its corresponding reduced CoFe2 O4 NS showed best OER performance than the reduced CoFe2 O4 bulk as well as the reduced CoFe2 O4 nanoparticles, implying the hollow nanospheres feature more accessible surface area than bulk and nanoparticles samples, thus greatly facilitate efficiency of NaBH4 reduction treatment. Graphical abstract: Highlights: NaBH4 as reductant has been to fabricate the reduced CoFe2 O4 nanosheets (NS). Rich oxygen vacancies on CoFe2 O4 NS lead to more active sites and better conductivity. Reduced CoFe2 O4 NS show better OER activity than the reduced bulk and nanoparticle. CoFe2 O4 hollow nanospheres exhibit most obvious improvement for OER activity.