Electrochromism and photocatalysis in dendrite structured Ti:WO3 thin films grown by sputtering

摘要

Titanium doped tungsten oxide (Ti:WO3) thin films with dendrite surface structures were grown by co-sputtering titanium and tungsten in Ar + O-2 atmosphere. Ti:WO3 thin films were deposited at oxygen flow rates corresponding to pressures in the range 1.0 x 10(-3)-5.0 x 10(-3) mbar. Argon flow rate and sputtering power densities for titanium (2 W/cm(2)) and tungsten (3 W/cm(2)) were kept constant. Ti:WO3 films deposited at an oxygen pressure of 5 x 10-3 mbar are found to be better electrochromic and photocatalytic. They have high optical modulation (80% at), lambda = 550 nm), coloration efficiency (60 cm(2)/C at), lambda = 550 nm), electron/ion storage and removal capacity (Qc: -22.01 mC/cm(2), Qa: 17.72 mC/cm(2)), reversibility (80%) and methylene blue decomposition rate (-1.38 mu mol/ld). The combined effects of titanium doping, dendrite surface structures and porosity leads to significant enhancement in the electrochromic and photocatalytic properties of Ti:WO3 films. (C) 2015 Published by Elsevier B.V.