High sensitivity ethylene glycol gas sensor based on CuO-In(OH)3 heterojunction at low temperature

With the advancement of automotive intelligence and electrification, ethylene glycol (EG), as a critical component in antifreeze and coolant systems, has gained increasing industrial significance. However, the volatile nature of EG poses potential health hazards, making the development of high-performance EG gas sensors an urgent priority. In this study, a CuO-In(OH) 3 Type II p-n heterojunction was directly fabricated through a solvothermal method followed by 200°C annealing. The developed CuO-In(OH)₃-based gas sensor demonstrates exceptional EG sensing performance, exhibiting a response magnitude of 21.3 toward 50 ppm EG at 95°C – 7.9 times higher than that of pure CuO (2.7). Notably, the operating temperature was reduced from 120°C (pristine CuO) to 95°C while maintaining excellent repeatability (6 cyclic tests) and long-term stability (26-day continuous operation). The first engineered heterojunction, characterized by its nanoflower-cube hierarchical architecture, not only provides a novel strategy for designing efficient EG gas sensors but also demonstrates promising potential in environmental safety assurance.