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  • 1 School of Materials Science & Engineering, Seoul National University, Gwanak-gu, Seoul 151-744, Republic of Korea
  • | 2 Department of Advanced Ceramic Materials Engineering, Gangneung-Wonju National University, Gangneung, Gangwon-do 210-702, Republic of Korea
  • | 3 School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do 440-746, Republic of Korea
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Abstract

Ta2O5 powder was heat treated in flowing NH3 at varying temperature for 2 h. When heat treated at 680–720 °C, nitrogen was doped to Ta2O5, but showed only a slight improvement of photocatalysis of rhodamine B dye in solution under visible light irradiation. From the heat treatment temperature of 740 °C, seeds of TaON and Ta3N5 formed newly and grew with the temperature. The optical absorption edge at 410–510 nm by TaON and absorption shoulder at 535 nm by Ta3N5 were observed. These specimens with N-doped Ta2O5, TaON, and Ta3N5 demonstrated notably improved photocatalytic performance, and the photocatalysis was facilitated by surface photosensitization.

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