Facile synthesis of WO3 fibers via centrifugal spinning as an efficient UV-and VIS-light-driven photocatalyst

Abstract

This paper demonstrates, for the first time, synthesis of uniform and crystalline WO3 mesopomus fibers with a diameter of approximate to 1 mu m via centrifugal spinning. This was achieved by using a stable aqueous precursor solution based on ammonium metatungstate (AMT, (NH4)6H(2)W(12)O(40)center dot xH(2)O)) and polyvinyl pyrrolidone (PVP, (C6H9NO)(n)). Annealing at 300 degrees C for 1 h followed by an additional annealing at 500 degrees C for 6 h was conducted to obtain crystalline WO3 fibers. The resulting centrifugally spun WO3 fibers possess approx. 1.4-4 times enhancement in photocatalytic activity under UV (k = 0.0205 min(-1)) and VIS (k = 0.0109 min(-1)) light irradiation compared to that of electrospun WO3 fibers and commercially available WO3 nanoparticles. This is due to the increased specific surface area of the centrifugally spun WO3 fibers (S-BET = 22.3 m(2)/g) compared to electrospun WO3 fibers (S-BET = 7.4 m(2)/g) and WO3 nanoparticles (S-BET = 6.4 m(2)/g). On the other hand, optical properties of all tested materials (including optical band gap) were nearly the same.This paper demonstrates, for the first time, synthesis of uniform and crystalline WO3 mesopomus fibers with a diameter of approximate to 1 mu m via centrifugal spinning. This was achieved by using a stable aqueous precursor solution based on ammonium metatungstate (AMT, (NH4)6H(2)W(12)O(40)center dot xH(2)O)) and polyvinyl pyrrolidone (PVP, (C6H9NO)(n)). Annealing at 300 degrees C for 1 h followed by an additional annealing at 500 degrees C for 6 h was conducted to obtain crystalline WO3 fibers. The resulting centrifugally spun WO3 fibers possess approx. 1.4-4 times enhancement in photocatalytic activity under UV (k = 0.0205 min(-1)) and VIS (k = 0.0109 min(-1)) light irradiation compared to that of electrospun WO3 fibers and commercially available WO3 nanoparticles. This is due to the increased specific surface area of the centrifugally spun WO3 fibers (S-BET = 22.3 m(2)/g) compared to electrospun WO3 fibers (S-BET = 7.4 m(2)/g) and WO3 nanoparticles (S-BET = 6.4 m(2)/g). On the other hand, optical properties of all tested materials (including optical band gap) were nearly the same.