Novel heterostructured InN/TiO2 submicron fibers designed for high performance visible-light-driven photocatalysis

Abstract

As a typical photocatalyst, TiO₂ can only absorb UV light limited by its wide band gap, which severely limits its industrial application. Seeking effective strategies to enable its visible light absorption is in the spotlight. In this paper, InN with a band gap of 0.7 eV was incorporated into TiO₂ nanofibers to obtain high-performance visible-light photocatalysts for the first time. Heterostructured InN/TiO₂ submicron fibers were facilely fabricated via an electrospinning technique followed by a nitridation procedure. InN was homogeneously distributed in the TiO₂ matrix, as characterized by transmission electron microscopy. Owing to the ultra-narrow band gap of InN, the light absorption of the InN/TiO₂ hybrid submicron fibers was broadened to visible wavelengths. The photocatalytic performance of the heterostructure was assessed through the decomposition of rhodamine B under visible light irradiation. Approximately 80% rhodamine B was decomposed in just 15 min. The rate constant reached up to 0.089 min⁻¹, which was enhanced 45 times compared with the electrospun TiO₂ fibers. This great improvement in the photocatalytic properties was attributed to both the intense visible-light absorption and the efficient charge separation enabled by the homogeneous distribution of the InN phase in the TiO₂ fibers. The photocatalytic efficiency achieved here was among the highest values of the currently reported photocatalysts. The results obtained in this work may pave a new way for the fabrication of high-performance visible-light photocatalysts.