One-step synthesis of oxygen-defects modified Ta2O5 nanosheets with high photocatalytic performance by chemical vapor deposition method

Abstract

Tantalum oxide is a semiconductor material with excellent physical properties, but its wide band gap limits its application in the field of photocatalysis. In this article, we synthesized novel hexagonal Ta2O5 nanosheets with oxygen defects in one step by chemical vapor deposition. The results suggest that Ta2O5 nanosheets prepared at 500 °C (3.49 eV) have excellent photocatalytic degradation ability, and the photodegradation efficiency for RhB is 4.3 times than commercial Ta2O5 (3.7 eV). The X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) results confirmed the existence of oxygen-defects in Ta2O5 nanosheets, and photoluminescence (PL) and photoelectric tests proved that oxygen- defects can form defect energy levels, thereby effectively promoting the separation efficiency of photogenerated carriers in Ta2O5 nanosheets. In addition, the contribution of reactive oxygen species (ROS) in photodegradation was obtained in the following order: 1O2, > h+ ≈ OH– ≈ O2–. The results indicated that singlet oxygen is used as the main active species in the photocatalytic degradation process of Ta2O5 nanosheets, and it can achieve high-efficiency degradation of RhB under the combined action of several other active species. This study synthesized a tantalum oxide material with a new structure through a simple method, and greatly enhanced the light absorption capacity of tantalum oxide, which provided a promising prospect for the application of tantalum oxide in the field of photocatalysis.