Cataluminescence Sensor Based on ZnO–CuO Composites for Rapid and Selective Detection of Hydrogen Sulfide

Hydrogen sulfide (H₂S) is a highly toxic and corrosive gas, necessitating rapid and selective detection strategies for environmental and occupational safety. In this work, a ZnO-CuO composites were rationally designed and synthesized via a hydrothermal route and evaluated as a cataluminescence (CTL) sensing material for H₂S monitoring. The sensor demonstrated a strong CTL response under mild operating conditions, offering a detection limit as low as 4 ppm, rapid response, and recovery within 2.5 s, and excellent selectivity against a broad panel of volatile organic and inorganic gases. Mechanistic investigations were conducted using BET surface analysis and energy band modeling based on the p-n heterojunction structure to explore the origin of signal enhancement in the ZnO-CuO composites. Validation with simulated gas mixtures confirmed good recovery and practical feasibility. These findings demonstrate the significant potential of ZnO-CuO composites for selective, sensitive, and rapid H₂S monitoring in the workplace.