Synthesis of BiPO4 polymorphic composite with enhanced photocatalytic activity

Abstract BiPO4 polymorphic composite powders comprising of monazite monoclinic (nMBIP, space group: P21/n) and monoclinic (mMBIP, space group: P21/m) phases were synthesized by a facile hydrothermal procedure using Bi(NO3)3·5H2O, H3PO4 and urea precursors. By controlling the amount of urea and hydrothermal temperature, both nMBIP- and mMBIP-rich composites with the composition of 79% nMBIP–21% mMBIP and 81% mMBIP-19% nMBIP were received readily and selectively, respectively. The photocatalytic activity of mMBIP-rich composite for rhodamine B degradation under 365 nm-UV illumination was pronouncedly higher than that of nMBIP-rich composite and two individual single-phase components. The improving in photocatalytic activity of mMBIP-rich composite was attributed to both { 1 ¯ 0 1 } -exposed facets of mMBIP plates and the phase junction of these plates with nMBIP nanocrystals nucleated on their exposed { 1 ¯ 0 1 } surfaces.