Interconnected graphene scaffolds for functional gas sensors with tunable sensitivity

In this work, the interconnected graphene scaffolds are prepared by three-dimensional (3D) printing for multifunctional gas detection with tunable sensitivity. The scaffolds with regularly aligned graphene conductive networks exhibit significant mechanical strength and high electrical stability to multi-direction deformation, which can be attributed to the typical core-shell structure of graphene and PVP. The resistance of the free-standing scaffolds can realize the real-time response to H 2 O and NO 2 , and the relative resistance change to 100 ppm H 2 O and 100 ppm NO 2 can reach 2% and 2.5 %, respectively. The charge doping of the oxidizing gases is considered to be the main reason for various response sensitivities of the scaffolds with different orthogonal layers, in which the interconnected conductive network can generate a large specific surface area and significantly improving the adsorption of the target gases and the transfer of charge. The controllable fabrication of regular structure has appropriately great potential for further optimizations and applications in gas detection.