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

Abstract

TiO₂ hollow nanocubes (HNCs) with a novel architecture are fabricated in large quantities by liquid-phase deposition synthesis using Cu₂O NCs as the template. The TiO₂ hollow cubic structure, characterized by mutually perpendicular rough faces, exhibits an average diameter of 1 μm and a high specific surface area of 43.52 m² g⁻¹. The detailed formation mechanism of the TiO₂ HNCs is systematically investigated by controlled experiments. Afterward, an ultraviolet photodetector (UVPD) based on the TiO₂ HNCs is assembled, which can achieve desirable self-powered performance over a wide range of UV light intensities. The device exhibits excellent photosensitivity and multicycle stability, demonstrated by the maximum response 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 accurate transmission of the information “UV” and high-clarity imaging of the Chinese characters “Guang Dian”.