MOF-derived ZnO nanocages photoelectrochemical photodetectors for high-performance self-powered visualized ultraviolet detection

Abstract

Excessive ultraviolet (UV) exposure is a well-established risk factor for various dermatological conditions, including solar dermatitis. Visualized and quantitative UV detection is gaining increasing attention. Conventional approaches employing photochromic composite materials have several limitations, including poor reversibility and high detection limits, which restrict their practical applicability. Herein, we constructed zeolitic imidazolate framework-8 (ZIF-8)-derived ZnO nanocage (NC)-based photoelectrochemical-type photodetector (PEC PD) via electrodeposition and thermal annealing. The ZnO NCs PEC PDs exhibit a good UV photoresponse, with a high responsivity of 91.51 mA W⁻¹ and response times of 23 ms (rise) and 87 ms (decay) under 365 nm irradiation in a neutral electrolyte, while exhibiting 156.30 mA W⁻¹ in 0.1 M KOH, outperforming most reported PEC UV PDs. Furthermore, integrating ZnO NCs photoelectrodes with Prussian blue counter electrodes enables real-time, visualized UV detection with a fast response and recovery speed. Developing a standardized colorimetric reference card provides a practical and user-friendly means for determining the UV index, facilitating routine UV monitoring and personal protection. Our work offers a new way for self-powered visualized UV detection.