Core–shell cobalt oxide mesoporous silica based efficient electro-catalyst for oxygen evolution

Content Provider	Semantic Scholar
Author	Khan, Shahid Ali Khan, Sher Bahadar Asiri, Abdullah M.
Copyright Year	2015
Abstract	In the last few decades, renewable resources received considerable attention for the production of hydrogen. Herein, we present oxygen evolution from water using cobalt oxide based nanomaterials (Co3O4, Co3O4@SiO2, Co3O4/TiO2, Co3O4/Fe2O3 and ZnO@SiO2). These nanomaterials were grown in a controlled size and were characterized by various spectroscopic techniques. The Co3O4, Co3O4@SiO2, Co3O4/TiO2, Co3O4/Fe2O3, and ZnO@SiO2 were screened for their electro-catalytic properties towards H2O oxidation. All cobalt oxide based nanomaterials showed good oxygen evolution activity and high stability in alkaline conditions. However, Co3O4@SiO2 showed a higher current density at lower overpotentials and a lower Tafel slope (107.7 mV dec−1) as compared to Co3O4/TiO2, Co3O4/Fe2O3, ZnO@SiO2, and Co3O4. At 1.0 V (overpotential 735 V versus Ag/AgCl), Co3O4@SiO2 supplied a current density of 63.0 mA cm−2 in 0.3 M KOH solution. This indicated a superior electrocatalytic performance then the other electrocatalyst. The excellent electrocatalytic performance of Co3O4@SiO2 might be due to certain structural features, which elevate its electrical conductivity, its oxidizing aptitude, and the affinity between OH− ions and the Co3O4@SiO2 surface and ultimately enhance smooth mass transports, which give superior oxygen evolution activity to Co3O4@SiO2.
Starting Page	5561
Ending Page	5569
Page Count	9
File Format	PDF HTM / HTML
DOI	10.1039/C5NJ00521C
Volume Number	39
Alternate Webpage(s)	https://pubs.rsc.org/en/content/getauthorversionpdf/C5NJ00521C
Alternate Webpage(s)	https://doi.org/10.1039/C5NJ00521C
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article