Facile one-step synthesis and enhanced photocatalytic activity of WC/ferroelectric nanocomposite

The development of noble-metal-free co-catalysts is seen as a viable strategy for improving the performance of
semiconductor photocatalysts. Although the photocatalytic efficiency of ferroelectrics is typically low, it can be enhanced through incorporation of co-catalyst into nanocomposites. Here, we demonstrate the influence of ferroelectricity on the decolorization of Rhodamine B under simulated solar light using RbBi2Ti2NbO10 and compared the performance with nonferroelectric RbBi2Nb5O16. The decolorization rate for RbBi2Ti2NbO10 was 5 times greater than RbBi2Nb5O16. This behaviour can be explained in terms of ferroelectric polarization, which drives separation of the charge carriers. The photocatalytic activity of the RbBi2Ti2NbO10 was further enhanced to over 30 times upon preparing nanocomposite with tungsten carbide (WC) through high energy ball milling. This enhancement was not only attributed to the increased specific surface area, but also to the incorporated WC co-catalyst which also serves as source of plasmonic hot electrons and extends the photocatalytic activity into the visible light range. The WC/RbBi2Ti2NbO10 nanocomposite shows interesting water oxidation property and evolves O2 with a rate of 68.5 μmol h-1 g-1 and the quantum yield of 3% at 420 nm. This work demonstrates a simple route for preparing WC containing nano ferroelectric composites for solar energy conversion applications.