Enhanced NO₂ sensing performance of CdS nanoparticle-modified PEDOT:PSS composite: A systematic study of ultrasensitivity and reliability

This study unveils a novel CdS/PEDOT:PSS composite sensor for ultra-sensitive and reliable NO₂ detection, addressing the critical need for reliable environmental monitoring. The sensing materials were synthesized through an innovative solvothermal method. Furthermore, the composite's structure and morphology were confirmed through XRD, FTIR, UV–vis spectroscopy, and FESEM. Compared to previously reported NO₂ sensors based on pure PEDOT:PSS or CdS, our composite sensor demonstrated superior performance with a linear response range of 100–400 ppm (R² = 0.99473), rapid response (73 s) and recovery (54 s) times at 100 ppm, and excellent selectivity. The synergistic effect of combining CdS nanoparticles with PEDOT:PSS resulted in a 2.2-fold increase in sensitivity compared to pure PEDOT:PSS. Unlike many reported sensors that operate at elevated temperatures, our composite sensor functions effectively at room temperature, making it more suitable for practical applications.