Hierarchical TiO₂ nanosheet‐assembled nanotubes with dual electron sink functional sites for efficient photocatalytic degradation of rhodamine B

Abstract

A novel Pt–TiO2/Ag nanotube photocatalyst has been synthesized successfully via a facile method. TiO2 nanotubes are assembled with numerous ultrathin TiO2 nanosheets and show a highly open structure. The gaps between adjacent TiO2 nanosheets can serve as channels for the access of reactants, accelerating the mass transfer process. During the fabrication process of the Pt–TiO2/Ag nanotube photocatalyst, high‐quality Pt–SiO2 nanotubes are synthesized first with the structure‐directing effect of polyvinylpyrrolidone. Then a TiO2 layer is coated on the outside surface of the silica nanotubes. The introduced titanium species can be converted into TiO2 nanosheet structure during the subsequent hydrothermal treatment, gradually constructing nanosheet‐assembled nanotubes. Lastly, after the introduction of another electron sink function site of Ag through UV irradiation, the Pt–TiO2/Ag nanotube photocatalyst with dual electron sink functional sites is obtained. The specially doped Pt and Ag NPs can simultaneously inhibit the recombination process of photogenerated charge carriers and increase light utilization efficiency. Therefore, the as‐synthesized Pt–TiO2/Ag nanotube catalyst exhibits a high photocatalytic degradation performance for rhodamine B of 0.2 min−1, which is about 3.2 and 5.3 times as high as that of Pt–TiO2 and TiO2 nanotubes because of the enhanced charge carrier separation efficiency. Furthermore, in the unique nanoarchitecture, the nanotubes are assembled with numerous ultrathin TiO2 nanosheets, which can absorb abundant active species and dye molecules for photocatalytic reaction. On the basis of experimental results, a possible rhodamine B degradation mechanism is proposed to explain the excellent photocatalytic efficiency of the Pt–TiO2/Ag nanotube photocatalyst.

New Magnetically Recyclable Reduced Graphene Oxide rGO/MFe2O4 (M= Ca, Mg)/Ag3PO4 Nanocomposites With Remarkably Enhanced Visible‐light Photocatalytic Activity and Stability

“…To elucidate photocatalytic degradation mechanism of organic pollutants over synthesized photocatalysts, the reactive species including ˙ OH, ( and h + involved in the photodegradation process were investigated. The photodegradation pathway of MB, MO and 4‐CP over the prepared photocatalysts could be inferred, which is illustrated in Scheme . To clarify the separation of photoinduced e − /h + pairs over the synthesized photocatalysts, it is essential to estimate the conduction band (CB) and valence band (VB) potentials of the samples.…”

Novel axial substituted subphthalocyanine sensitized titanium dioxide H12SubPcB‐OPh2OH/TiO2 photocatalyst: Synthesis, density functional theory calculation, and photocatalytic properties

“…[21][22][23][24] However, the photocatalytic technology based on titanium dioxide semiconductor also has problems such as low quantum decomposition, low light utilization, and difficulty in recycling. [25][26][27] In order to overcome these defects, various strategies have been employed to enhance the photoresponse activity of TiO 2 , including metal or nonmetal doping, [28][29][30][31][32] morphology controlling, [33,34] ion implantation, [35,36] photosensitization, [37,38] formation of semiconductor heterojunction, [39] and surface hybridization. [40] .…”