An electrochemical H₂S sensor based on the screen printing Fe@Pt/C/PTFE sensing electrode

A novel electrochemical gas sensor for sensitive detection of H₂S at room temperature is constructed based on the Fe@Pt/C composite material. The core-shell structured Fe@Pt catalyst was synthesized by a two-step reduction method and physically dispersed in Vulcan XC-72 carbon powders. The core-shell structure increases the effective catalytic surface area of Pt while significantly reducing the usage of the noble metal Pt, leading to improved catalytic performance and decreased production costs. Additionally, the mature screen-printing process is used to coat the catalyst film. A waterproof and breathable PTFE film was used as the substrate and the parameters in the screen printing process were also optimized to achieve the best gas sensing performance of the electrode film. Through the detection of hydrogen sulfide (H₂S) with different concentrations, it is found that the sensor strictly shows linear correlation in the range of 1-20 ppm, R² = 0.99974. Notably, the sensor exhibits high sensitivity (658.45 nA ppm^-1) and a low detection limit of 0.33 ppm. Moreover, the consistency and stability of the sensor are satisfactory. The constructed gas sensor is expected to be well applied to industrial H₂S detection.