Ce2S3/PMo3W9/polypyrrole ternary nanocomposit: Facile synthesis, photoelectric characteristics and photocatalytic applications

Abstract

A ternary nanocomposite Ce 2 S/PMo 3 W 9 /PPy were prepared to exhibit superior photocurrent responses, and performance improvement in photocatalytic Cr(VI) reduction was also demonstrated. • A ternary nanocomposite Ce 2 S/PMo 3 W 9 /PPy were synthesized. • Polyoxometalate PMo 3 W 9 is used as the electron acceptor. • PPy can prevent Ce 2 S 3 from photocorrosion. • Performance improvement in photocatalytic Cr(VI) reduction was demonstrated. Inorganic solid material Ce 2 S 3 of narrow band gap semiconductor enables an ideal visible light photocatalyst, but its disadvantages of both the photocorrosion and the faster electron-hole recombination substantially restrict its photocatalytic performance. In this work, we prepared a ternary nanocomposite Ce 2 S 3 /PMo 3 W 9 /PPy (PPy = polypyrrole), in which Ce 2 S 3 is used as the visible-light-active photocatalyst and polyoxometalate PMo 3 W 9 is used as the electron acceptor to facilitate electron-hole separation, and PPy can improve the electrical conductivity of the composite and prevent Ce 2 S 3 from photocorrosion. The photoelectric properties of Ce 2 S 3 /PMo 3 W 9 /PPy nanocomposite were experimentally characterized by the measurements of transient photocurrent responses, electrochemical impedance spectroscopy and surface photovoltage spectra. Furthermore, we investigate on photocatalytic performances of Ce 2 S 3 , Ce 2 S 3 /PMo 3 W 9 and Ce 2 S 3 /PMo 3 W 9 /PPy for reduction of Cr(VI), and Ce 2 S 3 /PMo 3 W 9 /PPy exhibited higher photocatalytic performance than the pure Ce 2 S 3 due to the energy level matching, achieving 28% increase in photocatalytic activity of Cr(VI) reduction.