Synergistic Architecture of BiVO4 Nanosheets Anchored ZnIn2S4 for Highly Sensitive and Rapid Detection of Ammonia

High-performance ammonia (NH 3 ) sensors have significant potential in practical applications, including air quality management, food safety, and health monitoring. In this work, an opulus flower-like sheet-on-sheet heterostructure (ZIS@BVO NS) consisting of BiVO 4 (BVO NS) nanosheets mounted ZnIn 2 S 4 (ZIS) nanoflowers is successfully synthesized using an ultrasound induced self-assembly process for highly sensitive detection of NH 3 . The ZIS@BVO NS sensor exhibited a significantly improved response ( R a /R g = 21.03) to 200 ppm NH 3 at an optimal operating temperature of 202°C, which is three times greater than that of pure BVO NS (7.4) and 8-fold higher than ZIS (2.7), respectively. Additionally, the heterostructure exhibited swift response (8   s) and recovery (13   s) durations. The improved performance was ascribed to the hierarchical nanostructure, which offered numerous active sites, greater surface permeability, and optimized gas diffusion processes owing to open channels and increased chemisorbed oxygen concentration. This study emphasizes an eco-friendly one-step synthesis route of ZIS@BVO NS heterostructure for accurate NH 3 monitoring in food safety, health, and environment, facilitating effective management and the early identification of dangerous ammonia buildup.