Preparation and photoelectrochemical characterization of WO3-loaded TiO2 nanotube arrays via radio frequency sputtering

• Published in: Electrochimica acta Vol. 77; pp. 128 - 136
• Main Authors: Lai, Chin Wei, Sreekantan, Srimala, E., Pei San, Krengvirat, Warapong
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 30.08.2012; Elsevier
• Subjects: Alternative fuels. Production and utilization; Anodization; Applied sciences; Chemistry; Density; Deposition; Electrochemistry; Energy; Exact sciences and technology; Fuels; General and physical chemistry; Hydrogen; Nanocomposites; Nanomaterials; Nanostructure; Photoelectrochemical; Photoelectrochemistry. Electrochemiluminescence; Radio frequencies; Radio frequency (RF) sputtering; Sputtering; Titanium dioxide; Titanium dioxide (TiO2) nanotubes; Tungsten; Tungsten oxides; Tungsten trioxide (WO3); Titanium dioxide (TiO2) nanotubes; Radio frequency (RF) sputtering; Tungsten trioxide (WO3); Anodization; Photoelectrochemical; Water; Photoelectrochemistry; Titanium IV Oxides; Scanning electron microscopy; Nanotube; Tungsten trioxide (WO; ); Titanium dioxide (TiO; X ray diffraction; Field emission microscopy; Surface structure; nanotubes; Anodizing; Morphology; Preparation; Tungsten VI Oxides; Photoelectrolysis; Photoanodes; Photoelectrode; Hydrogen production; Radiofrequency sputtering
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2012.05.092

Titanium dioxide (TiO2) nanotubes loaded with tungsten trioxide (WO3) were prepared using the radio-frequency (RF) sputtering technique to enhance the photoelectrochemical (PEC) water-splitting process. The incorporation of tungsten ions (W6+) onto the TiO2 nanotubes at a sputtering time of less than 1min dominated the formation of hybrid WO3–TiO2 nanotubes, as manifested by the formation of the WOTi bond. A long deposition time resulted in the accumulation of W on the nanotube surfaces and initiated the growth of a cauliflower-like structure. The resultant hybrid nanotubes exhibited significantly enhanced visible spectrum absorption and higher photoconversion efficiency compared to the pure TiO2 nanotubes. Hybrid WO3–TiO2 nanotubes deposited for 0.5min exhibited a high photocurrent density that reached 1.6mA/cm2, with a photoconversion efficiency of 2.65%. This behavior is attributed to the faster transport of photogenerated electron/hole pairs, which prevented backward reactions and reduced the number of recombination centers.