Photocatalytic performance and application outlook of 3D TiO2/titanium mesh modified by GO-Ag joined-deposition

In this paper, in-situ growth of titanium dioxide nanotubes on titanium mesh and deposition of silver (Ag) and graphene (GO) were combined to construct 3D catalysts. By introducing ultraviolet-A/Light emitting diodes (UVA-LEDs), the GO-Ag-TNTs/UVA-LEDs photocatalytic system was setup for methyl orange (MO) degradation. Herein, Ag and GO were doped by photoreduction deposition and hydrothermal reduction respectively, which the doping amount of Ag and GO was optimized, the optimal silver nitrate precursor concentration was 5 mM, and the optimal concentration of GO was 25 mg added into 90 mL of ethanol and deionized water. Additionally, Field emission scanning electron microscopy (FESEM), Raman, Fourier transform infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectrophotometer (UV-vis-DRS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Ultraviolet Photoelectron Spectroscopy (UPS) were utilized to directly and indirectly clarify the structural characteristics of the catalysts before and after loading, while photoelectric properties were checked by Electrochemical Workstation. Results showed that GO-Ag joint-doped TNTs sample exhibited the highest photocurrent response and lowest transfer charge resistance compared to other TNTs samples. As for MO degradation and TOC mineralization, GO-Ag optimally doped-TNTs sample enhanced photocatalytic effects (about 20% and 30% improvement respectively) compared with bare TNTs sample.