Construction of carbon quantum dots/single crystal TiO₂ nanosheets with exposed {001} and {101} facets and their visible light driven catalytic activity

Abstract

Carbon quantum dots were doped into anatase TiO2 single crystal nanosheets (TNS) with highly exposed {001} and {101} reactive facets by a facile solvothermal process.

Preparation of the heterojunction catalyst N-doping carbon quantum dots/P25 and its visible light photocatalytic activity

“…5a. π–π* transition of C=C bonds absorbs strong band center around 228 nm region wavelength and n–π* transitions of C=O and C=N bonds shows weak wide absorption ranging from 280 nm to 450 nm 29 . Any excitation light sited between this wide absorption range can resonant with the electron and excite it to the S1 state, so light wavelength from 280 nm to 450 nm can excite to produce the photoluminescent emission of the N-CDs.…”

“…Any excitation light sited between this wide absorption range can resonant with the electron and excite it to the S1 state, so light wavelength from 280 nm to 450 nm can excite to produce the photoluminescent emission of the N-CDs. It is well known that N-doping carbon quantum dots-based materials have one characteristic property, that is, fluorescence spectra is dependent on the excitation wavelength 29 . The N-CDs dispersion displays yellow color by nature light irradiation but blue color by a 365 nm light illumination as is shown in Fig.…”

“…In addition, the emission spectra show typical excitation laser wavelength dependent property, which suggests its complicate energy band composition, either in ground state or excited band. The XPS detected carbonyl and C-N groups in N-CDs will influence the energy band structures of C-dots sp 2 kernel and introduce additional energy stage 29 . These multiple electronic structures mix together and result in multiple electronic transition possibilities, broaden the absorption range.…”

“…Experimental procedure of N-CDs fabrication have been reported elsewhere in the literature and here cited with minor modifications 27–29 . Typically 4 mmol citric acid and 12 mmol urea were dissolved together in 20 ml distilled water, and then poured into a 100 ml Teflon lined hydrothermal reaction vessel.…”

Anatase TiO2 with Co‐exposed (001) and (101) Surface‐Based Photocatalytic Materials for Energy Conversion and Environmental Purification

“…As a kind of renewable environmentally friendly materials, carbon materials have become a research hotspot in the field of photocatalysis because of their advantages of high conductivity, large specific surface area and strong thermal stability. [54] Xiong et al [55] used the solvothermal method to uniformly disperse the (001)-(101)-TiO 2 nanocrystals on the surface of graphene oxide to form a (001)-(101)-TiO 2 /GO composite material. The introduction of GO not only enhanced the crystallinity of TiO 2 , but also promoted light absorption.…”