Bismuth vanadate, BiVO 4 , is a visible-light response semiconductor for photocatalysis applications such as organic pollutants degradation, oxygen production and carbon dioxide reduction. However, as a single-phase photocatalyst, BiVO 4 efficiency is limited by the unpreferable recombination of the photoexcited electron (e − ) and hole (h + ). Thus, strategies have been designed to enhance the photocatalytic efficiency by promoting the separation of electrons and holes. This can be done by controling the morphology and crystallographic facets of BiVO 4 , and by building p–n junction photocatalytic systems with a combination of n-type semiconductors (BiVO 4 ) and p-type semiconductors or a monoclinic–tetragonal heterostructure of BiVO 4 . In particular, a direct p–n junction photocatalytic system with tetragonal zircon-structured BiVO 4 (t-z) and monoclinic scheelite-structured BiVO 4 (m-s) combination has recently attracted attention. Here we review the synthesis of the monoclinic–tetragonal heterostructured BiVO 4 photocatalyst (m–t BiVO 4 ) by calcination, hydrothermal, microwave-assisted hydrothermal and solvothermal methods. m–t BiVO 4 formation and the transmission phase between t-z and m-s are controlled by the calcining temperature, precursor pH, metal doping content, type of solvent, implementation of precursors and reaction conditions. We discuss m–t BiVO 4 crystal structure, optical characteristics and photocatalytic principles. Successful formation of BiVO 4 crystals with a m-s/t-z heterostructure is based on data from X-ray diffraction (XRD), Raman and ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS). In the m–t BiVO 4 heterostructure, a direct p–n junction photocatalytic system is established. When this system is exposed to visible light, the electrons in the conduction band of m-s BiVO 4 , a n-type semiconductor, migrate easily to the conduction band of t-z BiVO 4 , while the holes on valence band of t-z BiVO 4 , a p-type semiconductor, move to the valence band of m-s BiVO 4 through an internal electric field. As a result, the e − /h + charge carriers are spatially separated.