Facile preparation of cyclized polyacrylonitrile modified FeWO4 with superior visible-light-driven photocatalysis

This paper reported the preparation of a novel high-performance visible-light-active photocatalyst (cyclized polyacrylonitrile (CPAN)/FeWO4 nanocomposite) from inexpensive and readily available polyacrylonitrile (PAN), FeSO4·7H2O, and Na2WO4·2H2O via a facile and practical approach. For the application to photocatalytic reduction of Cr(VI), the as-prepared CPAN/FeWO4 nanocomposite demonstrated not only substantially higher photocatalytic activity than FeWO4 nanoparticles, but also fairly good durability under visible-light irradiation. Besides, the as-prepared CPAN/FeWO4 also demonstrated a high efficiency in the visible-light-driven photocatalytic reduction of Cr(VI) in dilute black chromium-plating solution. The enhanced photocatalytic activity of the as-prepared CPAN/FeWO4 photocatalyst was attributed to the formation of n-p heterojunction, which facilitated the separation and transfer of photo-induced holes and electrons. Furthermore, the photocatalytic experimental conditions also heavily influenced the Cr(VI) reduction rate over the as-prepared CPAN/FeWO4 photocatalyst. This study provided useful information on the exploitation of PAN to modify semiconductor photocatalysts to create new higher efficiency visible-light-active CPAN/semiconductor composite photocatalysts.