Visible light photoelectrochemical responsiveness of self-organized nanoporous WO3 films

✍ Scribed by Wenzhang Li; Jie Li; Xuan Wang; Sha Luo; Juan Xiao; Qiyuan Chen

• Book ID: 103828255
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 971 KB
• Volume: 56
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2010.06.025

✦ Synopsis

Visible light-responsive WO 3 nanoporous films with preferential orientation of the (0 0 2) planes were prepared by anodization in neutral F --containing strong electrolytes. The pore diameter of the selforganized structure was estimated to be in the region of 70-90 nm. Voltages were applied by stepping, which positively influenced passivity breakdown and played a significant role in the formation of selforganized nanoporous films. Under visible light irradiation, the photocurrent density (at 1.6 V vs. Ag/AgCl) and maximum photoconversion efficiency generated by the annealed nanoporous film were 3.45 mA/cm 2 and 0.91%, respectively. The annealed nanoporous WO 3 films show maximum incident photon-to-current conversion efficiency of 92% at 340 nm at 1.2 V vs. Ag/AgCl. These values are higher than that of annealed compact WO 3 film due to the large interfacial heterojunction area. The photoelectrochemical activities and electronic conductivities were also enhanced by annealing crystallization, which removed the recombination centers.