Noble metal nanoparticles functionalized conductive Co3(hexaiminotriphenylene)2 chemiresistor for hydrogen sulfide detection at Room-Temperature

Metal-organic frameworks (MOFs) applied in chemiresistors is principally limited by their poor conductivity and low catalytic activity. Herein, we report an intrinsically conductive two-dimensional (2D) MOF Co3(hexaiminotriphenylene)2 [Co3(HITP)2], for hydrogen sulfide (H2S) sensing at room temperature (RT). The proposed conductive Co3(HITP)2 sensor exhibits high sensitivity and good selectivity toward H2S under various relative humidity (RH) at RT. Meanwhile, different amounts of catalytic Pd nanoparticles (NPs) are embedded in conductive Co3(HITP)2 for further improving the gas sensing performances. The sensing results confirm that the 2 mol% Pd functionalized Co3(HITP)2 gas sensor presents the best sensing properties to H2S under different humidity at RT. We extended the catalytic metal NPs to Au and Pt, and Au or Pt loading conductive Co3(HITP)2 sensors also show remarkably enhanced H2S sensing performance including high response and low limit of detection (LOD). While, the pristine and noble metal NPs functionalized Co3(HITP)2 gas sensors are affected by humid atmosphere due to water vapor adsorption on Co3(HITP)2. Finally, the catalytic effect of noble metal NPs on conductive Co3(HITP)2 for H2S sensing is also discussed. The obtained results provide a key insight into the high-performance conductive Co3(HITP)2 based gas sensors work at RT for H2S detection.