Enhanced Photoactivity of V鈭扤 Codoped TiO2 Derived from a Two-Step Hydrothermal Procedure for the Degradation of PCP鈭扤a under Visible Light Irradiation

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• 作者：Jinwen Liu ; Rong Han ; Yan Zhao ; Hongtao Wang ; Wenjing Lu ; Tongfeng Yu ; Yaxin Zhang
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：March 24, 2011
• 年：2011
• 卷：115
• 期：11
• 页码：4507-4515
• 全文大小：1080K
• 年卷期：v.115,no.11(March 24, 2011)
• ISSN：1932-7455

文摘

A new route to synthesize V-doped and V鈭扤 codoped titania nanocatalysts using a novel two-phase hydrothermal method applied in hazardous PCP鈭扤a decomposition was reported. The physicochemical properties were characterized, indicating that the crystallite surface area increased after both first hydrothermal (FH) V impregnation and second hydrothermal (SH) N implantation, whereas mesoporous framework shrinkage and enlargement resulted from FH and SH, respectively. ICP and EPR demonstrated that SH did not alter V content, but rather it induced paramagnetic V⁴⁺ increase. The V species was enhanced from the inner to the catalyst surface with V⁵⁺ as the dominant mode and the N dopant existed with substitutional nitrogen as the main structure. The optical red shift by low vanadium implantation was ascribed to the V2p state, mainly from V⁴⁺ species in the matrix. After SH incorporation, the substitutional N1s state, interstitial N鈭扥 state, and concomitant NOx were responsible for the strong visible absorption of V鈭扤鈭扵iO₂. The photodegradation rates of PCP鈭扤a by the remodified catalysts after SH were much larger than that of the mono-V-TiO₂ precursors fabricated in FH. SHNV02, SHNV05, and SHNV10 exhibited 2.4, 1.6, and 3.1 times promotion toward PCP鈭扤a decomposition, respectively. Moreover, other variations and the synergetic effects after two-phase treatments were adequately discussed and proven to be useful in facilitating photocatalytic promotion. This work provided a strategy for obtaining further enhancement of the synthesized catalyst by second-step modification to achieve the deep removal effect of contaminants.