Structure and photocatalytic performance of rice husk-like Ba-doped GaOOH under light irradiation

Using H2O2 as a green oxidant to produce fluorescent GaOOH nanomaterials from a liquid metal

We report a simple and rapid method for the synthesis of fluorescent gallium oxyhydroxide (GaOOH) nanoparticles from liquid Ga by a probe sonication method in the presence of H₂O₂ as an oxidant. The aspect ratio of the GaOOH nanoparticles is determined by the concentration of H₂O₂ and solution pH, as well as the probe energy and sonication time. Further surface modification with cyclodextrin to achieve biocompatibility for potential biomedical applications is reported where an example of cell uptake and fluorescence imaging is shown.

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.

Enhanced Photocatalytic Activity of Electrospun β-Ga2O3 Nanofibers via In-Situ Si Doping Using Tetraethyl Orthosilicate

β-Ga2O3 has attracted considerable attention as an alternative photocatalyst to replace conventional TiO2 under ultraviolet-C irradiation due to its high reduction and oxidation potential. In this study, to enhance the photocatalytic activity of β-Ga2O3, nanofibers are formed via the electrospinning method, and Si atoms are subsequently doped. As the Si concentration in the β-Ga2O3 nanofiber increases, the optical bandgap of the β-Ga2O3 nanofibers continuously decreases from 4.5 eV (intrinsic) to 4.0 eV for the Si-doped (2.4 at. %) β-Ga2O3 nanofibers, and accordingly, the photocatalytic activity of the β-Ga2O3 nanofibers is enhanced. This higher photocatalytic performance with Si doping is attributed to the increased doping-induced carriers in the conduction band edges. This differs from the traditional mechanism in which the doping-induced defect sites in the bandgap enhance separation and inhibit the recombination of photon-generated carriers.

Dispersed GaOOH rods loaded on the surface of ZnBiNbO5 particles with enhanced photocatalytic activity toward enrofloxacin

A GaOOH/ZnBiNbO₅ composite was constructed by loading dispersed GaOOH rods on the surface of ZnBiNbO₅ particles and characterizations, including SEM-EDS, XRD, FT-IR spectroscopy, XPS, and UV-Vis DRS, were performed to analyze the morphology, structure and optical properties of the GaOOH/ZnBiNbO₅ composite. The characterization results showed that ZnBiNbO₅ was not destroyed by a high temperature and high pressure in the solvothermal process and that GaOOH was successfully dispersed on the surface of ZnBiNbO₅. Simultaneously, there was a red-shift of the absorbance edge for GaOOH/ZnBiNbO₅ compared with those of pure ZnBiNbO₅ and pure GaOOH. The band gaps of ZnBiNbO₅, GaOOH and GaOOH/ZnBiNbO₅ were calculated to be 2.96 eV, 4.76 eV and 2.93 eV, respectively. The photocatalytic activity of GaOOH/ZnBiNbO₅ was explored by degrading enrofloxacin under illumination. After ultraviolet light irradiation for 60 min, the removal rate of enrofloxacin with GaOOH/ZnBiNbO₅ as a photocatalyst was 15.11% higher than that of pure ZnBiNbO₅ and was 29.29% higher than that of pure GaOOH. In addition, the contribution of the free radicals in the photocatalytic process was confirmed to be ·O₂⁻ > ·OH > h⁺. The construction of the GaOOH/ZnBiNbO₅ composite improved the performance of the single ZnBiNbO₅ photocatalyst and single GaOOH photocatalyst, thereby increasing their practical application potential.

A GaOOH/ZnBiNbO₅ composite was constructed by loading dispersed GaOOH rods on the surface of ZnBiNbO₅ particles and characterizations, including SEM-EDS, XRD, FT-IR spectroscopy, XPS, and UV-Vis DRS were performed.