Uniform Pt Nanoparticles Anchored on Graphdiyne Nanowalls for Sensitive and Rapid NO₂ Detection at Room Temperature

Vertical oriented graphdiyne (GDY) nanowalls with unique hierarchical porous structure hold great promise in room-temperature gas sensors owing to their naturally adjustable bandgap and excellent conductivity. However, large response time and low response value remain a great challenge in view of the chemical inertness of carbon skeleton. Herein, uniform Pt nanoparticles anchored on GDY nanowalls are developed. The Pt/GDY sensor has an enhanced sensing performance compared to the GDY sensor, with a sensing response value of up to 52% and a response time of down to 24 s for 100 ppm NO₂ at room temperature. The sensing mechanism is attributed to the bonding of sp-hybridized carbon in GDY with Pt, which significantly facilitates the charge transfer and activation adsorption of NO₂ molecules. This is further elucidated by in situ diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations. This study opens up a new surface engineering approach for confined gas sensors.