Morphological control of mesoporosity and nanoparticles within Co3O4-CuO electrospun nanofibers: quantum confinement and visible light photocatalysis performance
Date
2017-09Source Title
ACS Applied Materials and Interfaces
Print ISSN
1944-8244
Publisher
American Chemical Society
Volume
9
Issue
41
Pages
35757 - 35774
Language
English
Type
ArticleItem Usage Stats
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Abstract
The one-dimensional (1D) mesoporous and interconnected nanoparticles (NPs) enriched composite Co3O4-CuO nanofibers (NFs) in the ratio Co:Cu = 1/4 (Co3O4-CuO NFs) composite have been synthesized by electrospinning and calcination of mixed polymeric template. Not merely the mesoporous composite Co3O4-CuO NFs but also single mesoporous Co3O4 NFs and CuO NFs have been produced for comparison. The choice of mixed polymer templates such as polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) for electrospinning is responsible for the formation of 1D mesoporous NFs. The HR-TEM result showed evolution of interconnected nanoparticles (NPs) and creation of mesoporosity in all electrospun NFs. The quantum confinement is due to NPs within NFs and has been proved by the surface-enhanced Raman scattering (SERS) study and the UV-vis-NRI diffuse reflectance spectra (DRS). The high intense photoluminescence (PL) spectra showing blue shift of all NFs also confirmed the quantum confinement phenomena. The lowering of PL spectrum after mixing of CuO in Co3O4 nanofibers framework (Co3O4-CuO NFs) proved CuO as an efficient visible light response low cost cocatalyst/charge separator. The red shifting of the band gap in composite Co3O4-CuO NFs is due to the internal charge transfer between Co2+ to Co3+ and Cu2+, proved by UV-vis absorption spectroscopy. Creation of oxygen vacancies by mixing of CuO and Co3O4 also prevents the electron-hole recombination and enhances the photocatalytic activity in composite Co3O4-CuO NFs. The photocurrent density, Mott-Schottky (MS), and electrochemical impedance spectroscopy (EIS) studies of all NFs favor the high photocatalytic performance. The mesoporous composite Co3O4-CuO NFs exhibits high photocatalytic activity toward phenolic compounds degradation as compared to the other two NFs (Co3O4 NFs and CuO NFs). The kinetic study of phenolic compounds followed first order rate equation. The high photocatalytic activity of composite Co3O4-CuO NFs is attributed to the formation of mesoporosity and interconnected NPs within NFs framework, quantum confinement, extended light absorption property, internal charge transfer, and effective photogenerated charge separations.
Keywords
ElectrospinningMesoporous
Nanofibers
Phenolic compounds
Quantum confinement
Visible light
Absorption spectroscopy
Charge transfer
Complexation
Electrochemical impedance spectroscopy
Electromagnetic wave absorption
Electrospinning
Energy gap
Light
Light absorption
Mesoporous materials
Mixing
Nanofibers
Nanoparticles
Oxygen vacancies
Phenols
Photocatalysis
Polymers
Quantum confinement
Raman scattering
Semiconductor quantum wells
Spinning (fibers)
Surface scattering
Synthesis (chemical)
Ultraviolet spectroscopy
Diffuse reflectance spectrum
High photocatalytic activities
Mesoporous
Phenolic compounds
Surface enhanced Raman Scattering (SERS)
UV-Vis absorption spectroscopy
Visible light
Visible-light photocatalysis
Copper oxides
Permalink
http://hdl.handle.net/11693/37284Published Version (Please cite this version)
https://doi.org/10.1021/acsami.7b09026Collections
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