Abstract
AbstractWe demonstrate a bottom-up approach to fabricating a visible light-driven titania photocatalyst device bearing an embedded two-dimensional (2D) array of gold nanoparticles (AuNPs) as a near-field light-generating layer. The device is a layered structure prepared by depositing a 2D array of AuNPs on a transparent conductive substrate (10 nm indium tin oxide (ITO) layer on quartz), coating the 2D array of AuNPs with a monolayer of trimethoxyoctylsilane (TMOS), and depositing titania nanocrystals on the anchoring molecule (TMOS) layer. The visible light activity of the device was tested using photocatalytic degradation of methylene blue (MB) by illuminating the device with visible light (700 nm light) and ultraviolet (UV) light (250–380 nm). The localized surface plasmon resonance peak of the 36 nm AuNP 2D array is around 700 nm with a full-width at half-maximum of 350 nm. In comparison with other control samples, the device showed the highest photocatalytic activity with visible irradiation, which was 1.7 times higher than that of titania with UV irradiation. The origin of the visible light activity was confirmed by both quadratic incident light power dependency and action spectrum to be plasmon-induced (near-field enhancement by AuNPs) two-photon absorption.
Highlights
IntroductionThe introduction of impurities strongly affects the lifetime of the e–h pair (impurities act as recombination centers), and doping can decrease the corrosion resistance of the material (especially in the case of doping with transition metal ions).[11] Photosensitization of titania with organic dyes still presents major limitations for applications in photocatalysis due to the poor stability of the dye, which can undergo desorption, photolysis and oxidative degradation,[12,13] and fast back electron transfer, which results in low quantum yield for the photocatalytic reaction.[14] As an alternative to organic dyes, recently metallic nanostructures have been successfully used as photosensitizers for wide bandgap semiconductors[15,16,17,18,19] thanks to their broad and strong visible absorption based on localized surface plasmon resonance (LSPR) and their excellent chemical stability
Since the discovery in 1968 of photocatalytic water splitting by Honda and Fujishima,[1] titania has been intensively studied for its photocatalytic properties,[2,3] which could be used to convert solar energy to storable chemical energy by hydrogen production,[4] or to address environmental issues such as the treatment of waste water[5] and cleaning of exterior windows[6,7] by degradation of organic molecules
We planned to exploit the strong NF light induced by a 2D array of a fluorescent dye deposited on gold nanoparticles (AuNPs) to enable visible light activity in titania nanocystals deposited on the top of the array
Summary
The introduction of impurities strongly affects the lifetime of the e–h pair (impurities act as recombination centers), and doping can decrease the corrosion resistance of the material (especially in the case of doping with transition metal ions).[11] Photosensitization of titania with organic dyes still presents major limitations for applications in photocatalysis due to the poor stability of the dye, which can undergo desorption, photolysis and oxidative degradation,[12,13] and fast back electron transfer, which results in low quantum yield for the photocatalytic reaction.[14] As an alternative to organic dyes, recently metallic nanostructures have been successfully used as photosensitizers for wide bandgap semiconductors[15,16,17,18,19] thanks to their broad and strong visible absorption based on localized surface plasmon resonance (LSPR) and their excellent chemical stability. Our method of producing dense large-area 2D arrays of MNPs is expected to act as a powerful sensitizer for wide bandgap
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
