▎ 摘　　要

This paper reports the formaldehyde (HCHO) sensing mechanism of platinum nanoparticles (Pt) supported reduced graphene oxide (RGO)-based resistive sensor devices through the experimental investigation and subsequent density functional theory (DFT) computation. Sensing measurements conducted at room temperature revealed that the Pt facilitated enhanced charge transfer between HCHO molecule and RGO-Pt nanomaterial improves the response of the device by almost 4.5 times against 400 ppm of HCHO concentration as compared to bare RGO counterpart. The device has been found to recover within 350 s for an optimized impulsive heating treatment at 50 degrees C for 55 s. Moreover, the selectivity test performed for some common indoor volatile organic compounds signifies the RGO-Pt nanohybrid to be more specific toward the HCHO molecule. DFT-based first-principle calculations have also been carried out in terms of stable adsorption geometry, adsorption energy, net electron transfer, charge density difference, and changes in density of states of the HCHO adsorbed complexes. The simulation results suggest that the chemisorption of HCHO through molecular dissociation and strong covalent bond formation on RGO-Pt surface have led to significant changes in its resistivity in contrast to RGO, where HCHO molecule possesses pure physisorption. The simulation results agree quite well with the experimental observations.