Preparation and Photocatalytic Properties of a Hierarchical BiOCl/BiOF Composite Photocatalyst

Synergistic effects of rare earth doping and carbon quantum dots on BiOF/Bi2MoO6 heterojunctions for enhanced visible-near-infrared photocatalysis

Herein, we designed and synthesized a series of rare earth doped BiOF/Bi₂MoO₆ heterojunctions. The doping locations of rare earth ions were altered to determine the influence on the visible and near-infrared photocatalytic activity of heterojunctions. It is experimentally and theoretically confirmed that doping with Tm³⁺/Yb³⁺ in one semiconductor of the heterojunction produces superior photocatalytic efficiency than doping in both semiconductors. In addition, the near infrared photocatalytic efficiency strongly relied on upconversion luminescence from the Re³⁺ doped semiconductor in the heterojunction. By further modifying with CQDs, the CQDs/BiOF:Tm³⁺,Yb³⁺/Bi₂MoO₆ sample shows excellent visible and near-infrared photocatalytic performance, with 90% degradation of RhB occurring in the first 20 min under visible irradiation. This can be attributed to the large BET area, efficient photoinduced carrier separation and the upconversion process of the composite. This research will provide a systematic solution for realizing full-spectrum responsive and highly efficient photocatalysis by combination of rare earth ion doping, quantum dot modification and Z-scheme heterojunctions.

Synthesis of a GaOOH/ZnBiTaO5heterojunction photocatalyst with enhanced photocatalytic performance toward enrofloxacin

In this work, a GaOOH/ZnBiTaO₅ heterojunction photocatalyst was synthesized innovatively and characterization techniques including XRD, SEM-EDS, XPS, FT-IR, PL and UV-Vis DRS were carried out to analyse the structural and morphological properties of the GaOOH/ZnBiTaO₅ heterojunction photocatalyst. The GaOOH is dispersed on the surface of ZnBiTaO₅ to form a heterojunction structure according to the SEM image. The band gaps of 10 wt%, 25 wt% and 50 wt% GaOOH/ZnBiTaO₅ heterojunction photocatalysts were calculated to be 3.21 eV, 3.22 eV and 3.23 eV, respectively, which were between the band gaps of pure ZnBiTaO₅ (3.19 eV) and pure GaOOH (4.76 eV). The photocatalytic performance of the GaOOH/ZnBiTaO₅ heterojunction photocatalyst was investigated by degrading enrofloxacin under ultraviolet light. The results showed that the as-prepared 25 wt% GaOOH/ZnBiTaO₅ presented optimal photocatalytic performance and could remove 58.27% of enrofloxacin in 60 min, which was higher than that of pure ZnBiTaO₅ (53.7%) and pure GaOOH (35.4%). In addition, it was confirmed that ˙O₂⁻, h⁺ and ˙OH were all the active radicals during the degradation process. Finally, the possible degradation mechanism of enrofloxacin was discussed in detail. This work provided a viable strategy for improving the photocatalytic performance of wide band gap semiconductors.

A GaOOH/ZnBiTaO₅ heterojunction photocatalyst was synthesized innovatively and characterized by XRD, SEM-EDS, XPS, FT-IR, PL and UV-Vis DRS to analyse the structural and morphological properties of the GaOOH/ZnBiTaO₅ heterojunction photocatalyst.