Fabrication and application of ZIF-8 derived In2O3-ZnO nanocomposites for ultra-sensitive NO2 sensing under UV irradiation at room temperature

Nitrogen oxide (NO 2 ) is common by-products of industrial production, posing significant health risks to workers. Therefore, real-time monitoring of NO 2 is crucial. In this study, innovative In 2 O 3 -ZnO nano-materials were prepared by combining In 2 O 3 with ZIF-8 via electrospinning, for detecting trace amounts of NO 2 at room temperature (RT). Compared to pure In 2 O 3 , the In 2 O 3 -ZnO nano-materials (V2) with a 10 % weight ratio of ZIF-8 exhibited a significantly higher response (389.99) and a faster response time (16.9 s) to NO 2 under ultraviolet (UV) irradiation at RT. The superior gas sensing performance of the V2 nano-materials is attributed to the formation of n-n heterojunctions, enhanced optical absorption, increased oxygen vacancy ratio, and excellent dispersion among the nano-materials. The results demonstrate that V2 nano-materials can detect NO 2 at parts-per-billion (ppb) levels at RT, making them suitable for monitoring trace amounts of NO 2 in open environments. Furthermore, a portable real-time NO 2 monitoring device was constructed using V2 as the sensing material, an LM358-based amplifier circuit for data acquisition, an STM32F103C8T6 microcontroller as the main control unit, and a buzzer as an alarm device. Compared to devices using a helical Ni-Cr wire as an indirect heat source, this integrated NO 2 detection device offers real-time alarms with lower energy consumption. This application not only enhances worker health and safety in industrial environments but also demonstrates higher energy efficiency in practical application.