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论文类型：期刊论文

发表时间：2019-08-14

发表刊物：ACS APPLIED MATERIALS & INTERFACES

收录刊物：SCIE、PubMed

卷号：11

期号：32

页面范围：29004-29013

ISSN号：1944-8244

关键字：ZnFe2O4; facet engineering; photocatalytic activity; facet junction; H2O2 activation

摘要：Crystal facet engineering has been proved as a versatile approach in modulating the photocatalytic activity of semiconductors. However, the facet-dependent properties and underlying mechanisms of spinel ZnFe2O4 in photocatalysis still have rarely been explored. Herein, ZnFe2O4 nanoparticles with different {001} and {111} facets exposed were successfully synthesized via a facile hydrothermal method. Facet-dependent photocatalytic degradation performance toward gaseous toluene under visible light irradiation was observed, where truncated octahedral ZnFe2O4 (ZFO(T)) nanoparticles with both {001} and {111} facets exposed exhibited a superior performance than the others. The formed surface facet junction between {010} and {100} facets was responsible for the improved activity by separating photogenerated e(-)/h(+) pairs efficiently to reduce their recombination rate. Photogenerated electrons and holes were demonstrated to be immigrated onto {001} and {111} facets, separately. Intriguingly, electron paramagnetic resonance trapping results indicated that both center dot O-2(-) and (OH)-O-center dot were abundantly present in the ZFO(T) sample under visible light irradiation as major reactive oxygen species involved in the photocatalytic degradation process. Additionally, further investigation revealed that {001} facets played a predominant role in activating photogenerated transient species H2O2 into (OH)-O-center dot, beneficially boosting the intrinsic photocatalytic activity. This work has not only presented a promising strategy in regulating photocatalytic performance through the synergetic effect of facet junction and specific facet activation but also broadened the application of facet engineering with multiple effects simultaneously cooperating.