Au nanoparticle-doped Co3O4–CoFe2O4@SiO2 as a catalyst for visible-light-driven water oxidation. (4th July 2018)

• Record Type: Journal Article
• Authors: Ma, Wenlan; Li, Hui; Xu, Qian; Zhang, Yi; Wang, Wei; Wang, Jide
• Is Part Of: New journal of chemistry. Volume 42:Number 18(2018)
• Page Start: 14757
• Page End: 14765
• Publication Date: 2018-07-04
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c8nj01729h
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Composites of low dielectric constant SiO2, Au and metal oxide was obtained, it showed higher O2 evolution performance due to enhancing the electron transfer rate. Abstract : We proposed a facile method to systematically fabricate Co-based oxides as water oxidation catalysts (WOCs) for oxygen evolution under visible light irradiation. The results suggested that as-prepared Co3 O4 –CoFe2 O4, Co3 O4 –CoFe2 O4 @SiO2 and Co3 O4 –CoFe2 O4 @SiO2 @Au are excellent catalysts for the water oxidation reaction, while Co3 O4 –CoFe2 O4 @SiO2 @Au shows the best catalytic activity, and an O2 yield of 71.24% can be obtained. To gain insights into the relationship between the structural details and functional behaviors, the as-prepared catalysts were characterized using various analytical tools, respectively. SEM and TEM analyses showed that the average size of the nanoparticles was about 500 nm for the three catalysts and the surface of the Co3 O4 –CoFe2 O4 catalyst was covered by a floc layer of SiO2 . XRD and EDS studies confirmed that Au nanoparticles were present in Co3 O4 –CoFe2 O4 @SiO2 nanocomposites. From the above experimental results, we concluded that the reason why Co3 O4 –CoFe2 O4 @SiO2 @Au shows superior performance over the other two catalysts Co3 O4 –CoFe2 O4 and Co3 O4 –CoFe2 O4 @SiO2 may be due to: (1) the large refractive index and low dielectric constant of SiO2 ( ε = 1.56); (2) Au metal nanoparticles can effectively harvest a wide range of sunlight containing UV light and visible light because of its plasmonic effect. Our research showed that Co3 O4 –CoFe2 O4 @SiO2 @Au can be used as an efficient catalyst for water oxidation under visible light irradiation.