A novel strategy to enhance ultraviolet light driven photocatalysis from graphene quantum dots infilled TiO₂ nanotube arrays

Abstract

a Herein, a novel strategy has been proposed to fabricate graphene quantum dots (GQDs) infilled titanium dioxide (TiO 2 ) nanotube arrays (NTAs) hybrid structure for dye degradation of methylene blue (MB) under UV light (365 nm) irradiation. GQDs are infilled inside the TiO 2 NTAs (via anodic oxidation of a Ti sheet) through an impregnation method. Moreover, the morphology of the TiO 2 NTAs is well maintained after filling the GQDs inside, which is favorable for mass transfer. The peak intensity of photoluminescence (PL) spectra of the GQDs infilled TiO 2 NTAs catalyst is lower than that of annealed TiO 2 NTAs and a strong violet UV emission is obtained at 387 nm upon 252 nm deep UV excitation. The photocatalytic activities of the TiO 2 NTAs are evaluated in terms of the efficiencies of photo-decomposition and adsorption of MB in aqueous solution under UV light irradiation, after the impregnation of GQDs inside the TiO 2 NTAs. The highly-efficient photocatalytic activity is attributed to the broad absorption in the visible wavelength region, large photo-induced charge separation through the transfer of photogenerated electrons from the TiO 2 NTAs to GQDs, as well as the strong adsorption capacity of the GQDs to MB molecules. Thus, the GQDs infilled TiO 2 NTAs could be widely used as a photocatalyst for treating organic contaminants in the field of environmental protection.

Graphene Quantum Dots Decorated Titania Nanosheets Heterojunction: Efficient Charge Separation and Enhanced Visible‐Light Photocatalytic Performance

“…For example, Gupta et al. reported a photocatalyst based on efficient modification of TiO 2 nanotube arrays with GQDs through an impregnation method, and the obtained photocatalyst could efficiently photo‐decompose methylene blue in aqueous solution under ultraviolet light irradiation . Zhuo et al.…”

“…For example, Gupta et al reported ap hotocatalyst based on efficient modification of TiO 2 nanotube arrays with GQDs througha ni mpregnation method, and the obtainedp hotocatalyst could efficiently photo-decompose methylene blue in aqueous solution under ultraviolet light irradiation. [47] Zhuo et al developed the composite of GQDs/TiO 2 nanoparticles by an ultrasonic way for degradation of methylene blue. [48] Qu et al prepared GQDs with up-conversion properties and the heterojunction of GQDs/TiO 2 nanotubes by the hydrothermalm ethod.…”

Pristine and Graphene-Quantum-Dots-Decorated Spinel Nickel Aluminate for Water Remediation from Dyes and Toxic Pollutants

“…Moreover, GQDs can be prepared from cheap and accessible precursors [31,32]. Therefore, GQDs have already been used to form composites with inorganic semiconductors, which exhibited photocatalytic activity [33,34]. Nevertheless, to the best of our knowledge nickel and aluminum oxides or mixed Ni/Al oxides have not been examined in that context.…”

Reduced graphene oxide three-dimensionally wrapped WO3 hierarchical nanostructures as high-performance solar photocatalytic materials

“…In the past few years, many encouraging achievements have been made in the research of graphene-based semiconductor photocatalysts. [3][4][5] Graphene is a two-dimensional (2D) material composed of sp 2 -bonded carbon atoms that are linked in hexagonal shapes, with each carbon atom covalently bonded to three other carbon atoms. [6] Graphene has a large theoretical specific surface area, superior mobility of charge carriers, and high thermal/chemical stability.…”