Green-synthesized W- and Mo-doped BiVO4 oriented along the {0 4 0} facet with enhanced activity for the sun-driven water oxidation

• W- and Mo-doped BiVO4 powders with high exposure of {0 4 0} facets were prepared.
• Photocatalytic activity for the sun-driven water oxidation reaction was enhanced.
• The O2 evolution rate of the reference BiVO4 was doubled by Mo-doping.
• W- and Mo- superficial amounts have a main role on the photocatalytic activity.

A green hydrothermal synthesis approach, which employs almost neutral pH conditions and ammonium carbonate as a structural directing agent, has been used for the preparation of W- and Mo-doped BiVO4 powders with a monoclinic scheelite-like structure and preferential growth along the {0 4 0} facet. The crystal structure and morphology of the samples have been studied by means of XRD and FESEM analyses. The proper introduction of the W and Mo dopants in the lattice of BiVO4 crystals has been confirmed from XRD and XPS analyses. Moreover, it has been shown that the superficial amount of W and Mo dopants (obtained by means of XPS) plays a more important role than the overall (bulk and surface) dopant quantities in the BiVO4 (estimated by means of ICPMS analysis). The best of the so prepared materials demonstrated an extraordinary enhancement of the water oxidation rate under simulated sunlight (i.e. 942 μmol/g.h O2), which is about two-fold and 100 times higher than those of a state-of-art Mo-doped and the non-doped BiVO4 reference materials, respectively. The here reported BiVO4 photocatalysts are highly promising for different applications such as renewable energy production systems (i.e. solar fuels production form water and sunlight) and to resolve environmental issues (i.e. photocatalytic degradation of organic pollutants, water remediation, among others).

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