Perovskite Nanomaterials For Gas Sensing: Cu-Srtio₃ Thin Films As Ultrasensitive Co Sensors

This study demonstrates the exceptional carbon monoxide (co) sensing capabilities of nanostructured cuo-doped srtio₃ (cu-sto) thin films synthesized via spray pyrolysis. Structural characterization reveals a cubic perovskite phase with minor secondary phases (tio₂, srcu₃ti₄o₁₂), while morphological analysis confirms cu doping reduces grain size (~200 nm vs. ~800 nm for pure sto) and enhances surface area. The cu-sto sensor exhibits outstanding performance at 300°c, achieving a high response (s = 2000 to 1000 ppm co) with rapid response/recovery times (25 s/45 s). This enhancement is attributed to cuo-induced oxygen vacancies, catalytic surface reactions, and p-n heterojunction formation at grain boundaries. The sensor demonstrates excellent selectivity for co over interfering gases (h₂, lpg, nh₃, etc.) and stable repeatability. Electrical studies reveal ohmic behavior and semiconducting properties, with cu doping optimizing conductivity for gas detection. The synergistic effects of nanostructuring, doping, and heterojunction engineering position cu-sto as a promising material for ultrasensitive, low-temperature co monitoring in environmental and industrial safety applications.