  Bismuth based ternary oxide photocatalysts are of considerable interest in
photoelectrochemical water splitting. Yet these oxides are highly stable in
different environment, their relative inertness limits the available synthesis
routes to obtain desired stoichiometry on the final product. This report
describes a method to prepare barium bismuth niobate (specifically, Ba2(BiNb)O6
and Ba2Bi1.4Nb0.6 O6) target by sintering a mixture of individual oxides and
successfully fabricate desired barium bismuth niobate thin film on TCO
substrate. The surface morphology, physical, and chemical properties of thin
film were systematically investigated. Compositional uniformity was obtained by
sputtering in oxygen argon plasma environment and higher photocatalytic
activities were observed after subsequent surface treatments. Sodium fluoride
surface treatment further enhanced the photocurrent density and improved
electrode stability against corrosion. This work further suggests a viable
approach to improve the PEC performance of sputtered barium bismuth niobate by
modulating their fundamental energy states.
