Carbothermal Reduction Induced Ti³⁺ Self‐Doped TiO₂/GQD Nanohybrids for High‐Performance Visible Light Photocatalysis

Abstract

A facile calcination method is developed for the in situ synthesis of nanohybrids of Ti self-doped TiO /graphene quantum dot nanosheets (Ti -TiO /GQD NSs). Ti sites are formed on the surface of the TiO nanosheets through carbothermal reduction by GQDs, using citric acid as a carbon source. Such heterojunctions exhibit enhanced visible-light absorption properties, large photocurrent current densities, and low recombination of photoinduced carriers. The methylene blue (MB) and rhodamine B (RhB) photodegradation result demonstrates a higher visible-light photocatalysis performance than that of the original TiO . On one hand, inducing Ti sites is efficient for the separation of photogenerated charge carriers and for reducing electron-hole pair recombination. On the other hand, GQDs are beneficial for generating more photocurrent carriers and facilitating the charge transfer across the TiO surface. It is proposed that Ti sites and GQDs induced in TiO nanosheets have a synergistic effect, leading to excellent photocatalysis properties. Finally, a theoretical calculation is provided of the carbothermal reduction for the formation mechanism of the Ti defect sites.

Boosting Visible‐Light Photocatalytic Performance for CO2 Reduction via Hydroxylated Graphene Quantum Dots Sensitized MIL‐101(Fe)

“…[ 8,9 ] Compared with common semiconductors, GQDs are more environment friendly, low cost and photo‐stability. [ 10–12 ] High‐quality colloidal GQDs with excellent optical properties such as the broad‐spectrum response of visible light and various fluorescent are very suitable in diverse applications, such as bioimaging, [ 13,14 ] light emitting diodes [ 15–17 ] and photocatalysis, [ 18–20 ] especially CO 2 reduction. [ 21–23 ] Despite these significant advantages, pure GQDs nanoparticles have a poor CO 2 reduction catalytic property owing to their large exciton binding energy, [ 24 ] which greatly decreases the capability of separating electron–hole pairs.…”

Defective Anatase TiO2−x Mesocrystal Growth In Situ on g‐C3N4 Nanosheets: Construction of 3D/2D Z‐Scheme Heterostructures for Highly Efficient Visible‐Light Photocatalysis

“…0.29 eV) and visible-light response of DTMCs. [73,79,80] Having ar elatively narrow band gap of 2.81 eV,g -C 3 N 4 NSs can absorb light in the visible-light region. Therefore, under visible-light irradiation, both DTMCsa nd g-C 3 N 4 NSs can produce photogenerated electron/hole pairs.…”

“…The excess electrons tend to be delocalized over these sites, and a miniband is formed right below the conduction band (CB) of TiO 2 , which is responsible for the narrowing of the band gap (ca. 0.29 eV) and visible‐light response of DTMCs . Having a relatively narrow band gap of 2.81 eV, g‐C 3 N 4 NSs can absorb light in the visible‐light region.…”

Quenching-Induced Structural Distortion of Graphitic Carbon Nitride Nanostructures: Enhanced Photocatalytic Activity and Electrochemical Hydrogen Production

“…In addition, in self-doped TiO 2 , the obtained efficiency is not enough to degrade the hazardous pollutant. 40 Therefore, we need to explore new methodologies to improve the photocatalytic efficiency of the g-C 3 N 4 nanostructure.…”