Improving Visible Light-Absorptivity and Photoelectric Conversion Efficiency of a TiO2 Nanotube Anode Film by Sensitization with Bi2O3 Nanoparticles

Abstract

This study presents a novel visible light-active TiO2 nanotube anode film by sensitization with Bi2O3 nanoparticles. The uniform incorporation of Bi2O3 contributes to largely enhancing the solar light absorption and photoelectric conversion efficiency of TiO2 nanotubes. Due to the energy level difference between Bi2O3 and TiO2, the built-in electric field is suggested to be formed in the Bi2O3 sensitized TiO2 hybrid, which effectively separates the photo-generated electron-hole pairs and hence improves the photocatalytic activity. It is also found that the photoelectric conversion efficiency of Bi2O3 sensitized TiO2 nanotubes is not in direct proportion with the content of the sensitizer, Bi2O3, which should be carefully controlled to realize excellent photoelectrical properties. With a narrower energy band gap relative to TiO2, the sensitizer Bi2O3 can efficiently harvest the solar energy to generate electrons and holes, while TiO2 collects and transports the charge carriers. The new-type visible light-sensitive photocatalyst presented in this paper will shed light on sensitizing many other wide-band-gap semiconductors for improving solar photocatalysis, and on understanding the visible light-driven photocatalysis through narrow-band-gap semiconductor coupling.

Sensitive and Selective Detection of Tartrazine Based on TiO2-Electrochemically Reduced Graphene Oxide Composite-Modified Electrodes

“…The sensitivity (3.5 μA/μM) toward tartrazine was improved significantly with a low limit of detection (0.22 μM), due to the large surface area and high electrical conductibility of the MWCNTs [ 13 ]. Multi-walled carbon nanotubes–film-coated glassy carbon electrodes have also been proposed to determinate tartrazine, and successfully applied to determinate tartrazine in soft drinks [ 14 ]. Gold nanorods–graphene-modified electrodes were developed for the sensitive determination of tartrazine, and exhibited a linear response in the concentration range of 0.03–6.0 μM, with a detection limit of 8.6 nM [ 15 ].…”

Characterization of the Ge/Bi2O3 Interfaces

“…This material is also used to produce multifunctional devices that can exhibit ferroelectric, ferromagnetic and magnetodielectric coupling characteristics at the same time 4 . In addition, the sensitization of the TiO 2 with Bi 2 O 3 nanoparticles is reported to play remarkable improvements in the visible light absorbability and enhanced the solar energy efficiency 5 .…”

Facet-Dependent Cuprous Oxide Nanocrystals Decorated with Graphene as Durable Photocatalysts under Visible Light

“…Therefore, many studies have been dedicated to enhancing visible light-active photocatalysis by enhancing the segregation of electron-hole pairs. For instance, incorporating ions into the semiconductor [ 16 , 17 , 18 , 19 , 20 , 21 ], sensitization with dyer and surface complex [ 22 , 23 , 24 ], and coupling two or more semiconductors [ 25 , 26 ]. Moreover, well-defined facets of Cu 2 O which exhibit unique crystallographic properties related to different atomic terminated arrangements have been demonstrated to make a great improvement to photocatalysis [ 27 , 28 , 29 ].…”