Amino Acid-Assisted Hydrothermal Synthesis of BiVO4 with Highly Exposed (040) Facets and Enhanced Visible-Light-Driven Photocatalytic Properties

摘要

Highly efficient visible-light-response bismuth vanadate (BiVO4) crystals with preferentially exposed (040) facets have been hydrothermally synthesized in the presence of amino acids (L-glycine, L-glutamate or L-arginine) as morphology-directing agents for the first time. The effects of different amino acids on the synthesis of photocatalysts have been studied by means of X-ray diffractometer (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and UV-vis diffuse reflectance spectroscopy (DRS) techniques. The results revealed that the amino acids as the directing agents could influence the preferential crystal growth of monoclinic BiVO4 along its (040) facets, as well as the morphology and crystalline structure. The photocatalytic activities of BiVO4 samples were evaluated by the degradation of methylene blue (MB) under visible-light irradiation (420 nm < lambda < 800 nm). It was confirmed that the photocatalytic activities of BiVO4 prepared using amino acids as the directing agents were enhanced. The excellent photocatalytic activities of BiVO4 can be attributed to the prompt charge carrier mobility and the high separation efficiency of photogenerated electron-hole pairs facilitated by the presence of more photogenerated electrons on the larger (040) surface of BiVO4.