TiO₂/Graphitic Carbon Nitride Nanosheets for the Photocatalytic Degradation of Rhodamine B under Simulated Sunlight

Abstract

Surface-fluorinated ultrathin anatase TiO2 nanosheets with exposed (001) crystal planes were synthesized via a relatively low temperature solvothermal route. These two-dimensional (2D) TiO2 nanosheets demonstrated higher photocatalytic activity for degrading Rhodamine B (RhB) under simulated sunlight illumination than the corresponding sample with less fluorine ions (F–) content, which indicates the positive effect of F– on the enhanced photocatalytic performance of TiO2 nanosheets. Furthermore, 2D/2D TiO2/g-C3N4 nanosheet heterojunctions were fabricated through a solvent evaporation process. The photocatalysis test showed that TiO2/g-C3N4 exhibited higher photocatalytic performance for degrading RhB under simulated solar light illumination than pure g-C3N4 and TiO2 nanosheets. Based on free radical trapping experiments, superoxide radicals (·O2–) and photoinduced holes (h+) were determined to be the predominant active species for photodegrading RhB. A direct Z-scheme charge transfer mechanism is proposed to understand the enhanced photocatalytic activity in TiO2/g-C3N4 nanosheet heterojunctions.

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

“…However, it is still controversial whether the photo-induced electrons and holes transfer mechanism in the g-C 3 N 4 /(001)-(101)-TiO 2 heterojunction follows the Z-system or type II heterojunction. Therefore, Zhang et al [58] conducted research on this issue. They synthesized 2D/2D g-C 3 N 4 /TiO 2 nanosheets by solvent evaporation.…”

“…Possible charge transfer mechanism in the TiO 2 /g-C 3 N 4 heterojunctions photocatalytic reaction under stimulated sunlight illumination. [58] Figure 7. (A) Photocatalytic H 2 evolution amounts after simulated sunlight irradiation for 1 h over pure and lanthanide-doped TiO 2 nanosheets (W/O denotes undoped TiO 2 nanosheets); (B) photocatalytic H 2 evolution amounts after simulated sunlight irradiation for 1 h over TiO 2 nanosheets doped with different contents of Yb 3 + ions; (C) photocatalytic H 2 evolution plots of pure (a) and Yb 3 + -doped (b) TiO 2 nanosheets; (D) photocatalytic H 2 evolution amounts of Yb 3 + -doped TiO 2 nanosheets loaded with different contents of Pt nanoparticles after simulated sunlight irradiation for 1 h; (E) photocatalytic H 2 evolution plots of pure (a) and Yb 3 + -doped (b) TiO2 nanosheets loaded with 0.3 wt % Pt.…”

One-Pot Synthesis of TiO2/Hectorite Composite and Its Photocatalytic Degradation of Methylene Blue

“…Titanium dioxide (TiO 2 ) is considered one of the most promising photocatalysts because of its advantages of good chemical stability, nontoxicity, and low cost to degrade organic pollutants in the field of printing and dyeing [5,6]. However, TiO 2 has a wide band gap (3.0-3.2 eV) and excitation light is limited to ultraviolet light (4%), which greatly decreases its utilization efficiency of solar energy [7]. In addition, TiO 2 nanoparticles exhibit a low specific surface area, easy aggregation, and poor recycling, which limit its application range [8].…”

Element-doped graphitic carbon nitride: confirmation of doped elements and applications

“…Therefore, tremendous efforts have been made to overcome the shortages above, containing preparation of g-CN-based composites, modification of precursors, post-treatment of g-CN, exfoliation, element doping, and so on. [20][21][22][23][24][25][26][27][28][29] Element doping is a potential strategy to enhance the performance of g-CN, thus the doping of various elements has been reported in recent years. Different from g-CN-based composites, element-doped g-CN always involves the changes of the microstructure of g-CN, such as loss of graphitic structure 30 and impact to the in-plane ordering of tri-s-triazine units.…”