| 摘要: | V2O5 nanostructures (NSs) with varying morphologies, including nanoparticles, nanorod-like nanoparticles, and faceted nanorod-like nanoparticles were synthesized using the sol−gel method, followed by thermal treatment at 500 °C and 1 atm for 2 h. Various techniques, including thermal-field scanning electron microscopy, x-ray diffraction, and high-resolution transmission electron microscopy were used to determine the morphologies and crystal structures of these NSs. The optical bandgaps were evaluated using the UV–visible absorption spectra. The specific surface areas were estimated using the Brunauer-Emmett-Teller method. The defect types were identified using Raman spectroscopy, x-ray photoelectron spectroscopy, and electron paramagnetic resonance spectroscopy. Among the different morphologies, the faceted nanorod-like V2O5 nanoparticles exhibited a CO2 photocatalytic efficiency to CH4 of 11.85 μmole-g−1, which was approximately 6.19 and 0.80 times higher than that of nanoparticles (1.65 μmole-g−1) and nanorod-like nanoparticles (6.59 μmole-g−1), respectively. The factors enhancing CO2 photocatalytic efficiency included (1) increased specific surface areas, (2) formation of V4+/V5+ and VO∙∙ defects, (3) enhanced light absorption efficiency, (4) faceted nanorod morphology, and (5) build-in electric field. Furthermore, these results suggested that electrons play a crucial role in CO2 photocatalytic process, whereas holes play a supporting role. This study further highlighted the potential of faceted nanorod-like V2O5 nanoparticles for applications in CO2 photocatalytic process. |
