One-step synthesis of ZnO/SnO2-CNF nanocomposites for sensitive NO2 detection under UV illumination

Abstract

Nitrogen dioxide (NO₂) detection is critical for environmental and industrial safety, yet existing sensors often suffer from limited sensitivity and slow response. To address this, we report a facile one-step hydrothermal synthesis of ZnO/SnO₂ heterostructures via a one-step hydrothermal method using cellulose nanofiber (CNF) as a templating agent. Under UV activation, the optimized composite demonstrates a high response value of 45 toward 3 ppm NO₂, along with rapid response and recovery times of 15 s and 20 s, respectively. The CNF-assisted synthesis significantly enhanced NO₂ sensitivity and selectivity compared to conventional methods, attributed to synergistic effects of increased surface area and interfacial charge transfer. This scalable approach enables high-performance NO₂ sensors for real-time monitoring.