Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy.The materials were characterized by means of the XRD,Raman,TGA/DSC,SEM,XPS,and UV-Vis techniques.The photocatalytic activities of the BiVO4 materials were evaluated for the degradation of Methyl Orange under visible-light irradiation.It is observed that pH value and surfactant exerted a great effect on the morphology and pore structure of the BiVO4 product.Spherical BiV04 with porous structures,flower-cluster-like BiVO4,and flower-bundle-like BiVO4 were generated hydrothermally at lOO℃ with poly(vinyl pyrrolidone)(PVP)and urea(pH =2)and at 1600C with NaHCO3(pH =7 and 8),respectively.The PVP-derived BiVO4 showed much higher surface areas (5.0-8.4 m2/g)and narrower bandgap energies(2.45-2.49 eV).The best photocatalytic performance of the spherical BiVO4 material with a surface area of 8.4 m2/g was associated with its higher surface area,narrower bandgap energy,higher surface oxygen vacancy density,and unique porous architecture.