Fabrication Of The Porous BiVO₄Film And Its Photoelectrocatalytic Performance Under Visble Light

Titanium dioxide (TiO2), an oxide semiconductor, is regarded as a suitable material for various photocatalytic applications because of its strong oxidizing power, high chemical inertness, low cost, and long-term stability. However, a large bandgap (3.2eV) of TiO2restricts its use only to the narrow light-response range of ultraviolet (only about3-5%of total sunlight). Therefore, new and more efficient visible-light photocatalysts are being sought with a view to meeting the requirements of future environmental and energy technologies driven by solar energy. The porous BiVO4area was successfully fabricated through modified metalorganic decomposition (MOD) method using the polystyrene sphere (PS) as a pore former. It revealed that the photocatalytic activity of degradation pollutants with the porous BiVO4film is more outstanding than the BiVO4film. The main research contents and conclusion are as follows:(1) The porous BiV04was synthesized by the modified MOD method on F-doped SnO2(FTO) glass employed the polystyrene sphere as a pore former. The porous BiVO4film fabricated with the different concentration of PS were characterized by scanning electron microscope (SEM), diffused reflectance spectroscopy (DRS) and X-ray diffractometry (XRD). The effect of the morphology, crystalline type, size and photoelectrochemical (PEC) performance of the porous BiV04film were investigated. The results revealed that the porous BiV04film contained ca-200nm pore structure. Sample S200showed the sponge-like shape, and contained rich pores due to the PS as the pore former. The DRS illustrated that the porous BiV04film showed excellent visible light response and the best intensity of the visible light response could be achieved by the sample S200, and it was4.5-fold than of the So. The XRD result showed that the porous BiV04films were monoclinic form. The photoelectric characteristic data revealed that the sample S200showed the strongest intensity. The PEC activity of degradation methylene blue and phenol by the porous BiVO4films were2.7-fold and2.29-fold respectively, compared with the pristine BiVO4film, under visible light irradiation. (2) The porous Ag/BiVO4films were fabricated by photoreducing method. The porous Ag/BiVO4films were characterized by SEM, DRS and XRD. The diameter of Ag particle loaded on the BiVO4was around10～20nm. The photocurrent density of the porous Ag/BiVO4films enhanced distinctly to the porous BiVO4films under0.2V bias. And the kinetic constant of PEC degradation of phenol by the porous Ag/BiVO4film was1.47-fold than that of the porous BiVO4film.