Synergetic promotion on photoactivity and stability of W₁₈O₄₉/TiO₂ hybrid

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• 作者：Zhen-Feng Huang ; Ji-Jun Zou ; Lun Pan ; Songbo Wang ; Xiangwen Zhang ; Li Wang
• 关键词：W18O49 ; TiO2 ; Photocatalysis ; Hybrid photocatalyst ; Hetero-junctions
• 刊名：Applied Catalysis B: Environmental
• 出版年：5 April, 2014
• 年：2014
• 卷：147
• 期：Complete
• 页码：167-174
• 全文大小：1662 K

文摘

Hybrid photocatalysts were constructed by mixing W₁₈O₄₉ with commercial TiO₂ (P-25) and tested for photodegradation of pollutants (methyl orange and phenol). W₁₈O₄₉ synthesized by alcohothermal method possesses urchin-like structure, high surface area of 178 m² g^鈭? and wide light absorption in 200-800 nm. Although W₁₈O₄₉ alone shows low photoactivity, the hybrid shows significant synergetic promotion. The activity of W₁₈O₄₉(10 wt%)/TiO₂ under UV-vis light and W₁₈O₄₉(90 wt%)/TiO₂ under visible light is 2.43 (2.64) and 1.31 (1.52) times of calculated value without considering the synergy for the degradation of MO (phenol), respectively. Controlled experiments indicate 路O₂^{鈭?/sup> from reduction of O₂ by photo-induced electrons is the key active species in the photodegradation. The synergy was attributed to the well-matched band structure of two semiconductors that enhances charge separation, with electrons moving to W₁₈O₄₉ and holes to TiO₂, as confirmed by photo-deposition of Au and PbO₂. Furthermore, W₁₈O₄₉/TiO₂ is much more active than WO₃/TiO₂ attributed to the good reductive capability and wide light absorption of oxygen vacancies in W₁₈O₄₉. Moreover, the unstable W₁₈O₄₉ shows excellent stability in the hybrid.}