A comparative study on photoelectrochemical performance of TiO2 photoanodes enhanced by different polyoxometalates

• Published in: Electrochemistry communications Vol. 30; pp. 38 - 41
• Main Authors: Sun, Zhixia, Li, Fengyan, Zhao, Mingliang, Xu, Lin, Fang, Shuna
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-05-2013; Amsterdam Elsevier; New York, NY
• Subjects: Chemistry; Electrochemistry; Electron transport; Electron–hole recombination; Exact sciences and technology; General and physical chemistry; Photoelectrochemical performance; Photoelectrochemistry. Electrochemiluminescence; Polyoxometalates; TiO2; Polyoxometalates; Electron–hole recombination; Electron transport; Photoelectrochemical performance; TiO2; Heteropolysalt; Photoelectrochemistry; Titanium IV Oxides; Scanning electron microscopy; Electron-hole recombination; Hole; Electron transfer; Potassium Compounds; Surface structure; Tungsten Complexes; Morphology; TiO; Performance; Photoanodes; Photoelectric current; Comparative study; Photoelectrode; Electrochemical impedance spectroscopy
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2013.02.006

Based on the incorporation of polyoxometalates (POMs) into TiO2 film, the photoelectrochemical performance of POMs/TiO2 anode was elucidated by comparative investigation on the electron transport and electron–hole recombination in POMs/TiO2 anode. The photoelectrochemical performance of the POMs/TiO2 anode was clearly dependent on the type and content of POMs. Compared to the TiO2 anode, the POMs/TiO2 anode with low POMs loadings (0.75%) displayed the enhanced photoelectrochemical performance, while the excessive content (7.5%) of POMs could almost cause a negative effect. Thus, POMs could act as either “shallow electron trap” or “deep electron trap” depending on the different types and contents of POMs. This study reveals that the introduction of POMs into TiO2 anode could facilitate photogenerated electron transfer and reduce electron–hole recombination, which is urgently desired to develop advanced composite materials of POMs/TiO2 for application in photoelectrochemical catalysis and solar cells.
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► The photoelectrochemical performance of POMs/TiO2 anode was elucidated by comparative investigation. ► The POMs/TiO2 films displayed the enhanced photoelectrochemical performance. ► Their photoelectrochemical performance was dependent on the type and content of POMs. ► The role of POMs in TiO2 was investigated by electrochemical impedance spectroscopy. ► POMs could act as either “shallow electron trap” or “deep electron trap”.