Large-scale and facile synthesis of TiO2 hollow nanocubes for self-powered ultraviolet photodetector enabling optical communication and imaging

Abstract

A novel architecture of TiO₂ hollow nanocubes (HNCs) are fabricated in large quantities by a liquid phase deposition synthesis using Cu₂O NCs as template. The TiO₂ hollow cubic structure, characterized by mutually perpendicular rough faces, exhibits an average diameter of 1 μm and high specific surface area of 43.52 m² g^-1. The detailed formation mechanism of TiO₂ HNCs is systematically investigated by controlled experiments. Afterward, an ultraviolet photodetector (UVPD) based on TiO₂ HNCs is assembled, which can achieve desirable self-powered performance for a wide range of UV light intensities. The device exhibits excellent photosensitivity and multicycle stability, demonstrated by the maximum respond time of only 105/133 ms and the nearly unchanged photodetection performance after 200 consecutive cycles. Furthermore, taking advantage of the desirable performance, the TiO₂ HNCs UVPD serves as the signal receiving unit without bias, ultimately achieving the accurate transmission of the information “UV” and the high-clarity imaging of the Chinese character image “Guang Dian”.