A building blocks strategy for preparing photocatalytically active anatase TiO2/rutile SnO2 heterostructures by hydrothermal annealing

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:505

Article

de Mendonca, Vagner Romito¹  Avansi, Waldir, Jr.²  Arenal, Raul^3,4  Ribeiro, Caue⁵ 

[1] Inst Fed Sao Paulo, Campus Itapetininga, BR-18202000 Itapetininga, SP, Brazil

[2] Univ Fed Sao Carlos, Dept Fis, POB 676, Sao Paulo, Brazil

[3] Univ Zaragoza, Lab Microscopias Avanzadas, INA, Calle Mariano Esquillor, Zaragoza 50018, Spain

[4] ARAID Fdn, Zaragoza 50018, Spain

[5] Embrapa Instrumentacao, Lab Nacl Nanotecnol Aplicada Agron LNNA, BR-13560970 Sao Carlos, SP, Brazil

关键词: Heterostructure;    TiO2;    SnO2;    Oriented attachment;    Photocatalysis;   

DOI  :  10.1016/j.jcis.2017.06.024

来源: Elsevier

【 摘 要 】

Effective heterostructures for photocatalysis need to present good electron-hole mobility among phases, a feature that is only attained with satisfactory interface quality. For very small sizes and with a stable colloidal state, the oriented attachment mechanism can be used to prepare suitable structures by means of a building blocks strategy, whereby preformed nanoparticles are used to control the desired amount of each phase in the heterostructure. Here, we show the success of this strategy for anatase TiO2/rutile SnO2 heterostructures, applying conventional hydrothermal annealing, where successive collisions among particles increase the probability of oriented attachment. The photodegradation of Rhodamine B in water under UV radiation was used as a probe reaction to evaluate formation of the heterostructure, as indicated by an increase in photoactivity. Increased heterostructure photoactivity was related to heterojunction formation and charge separation. The increased lifetimes of the photogenerated charges, due to heterojunction formation, enabled them to reach the oxides surface and promote photocatalytic reactions. The insights presented here may be used in a rationalized synthesis method to obtain heterostructures from preformed nanocrystals. (C) 2017 Elsevier Inc. All rights reserved.

【 授权许可】

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