Heterojunction-Engineered Reduced Graphene Oxide/SnO₂ with Mesoporous Structures for Gas Chemosensors

Rapid and effective detection of potent volatile organiccompounds(VOCs) at low operating temperatures is of great significance to keephumans safe from these environmental pollutants. In this work, weshow the facile synthesis of two-dimensional (2D) and three-dimensional(3D)-laminated SnO2 nanomaterials that are decorated withreduced graphene oxide (rGO) and their efficient chemosensing propertiesfor the potent VOC triethylamine (TEA). The as-prepared hybrid material(rGO/SnO2) possesses p-n-type heterojunction and mesoporousstructures that are composed of self-assembled SnO2 nanoparticles.The heterojunction between rGO and SnO2 in this hybridmaterial can be tuned by varying the relative amount of rGO in it.Because of its 3D/2D structures and p-n heterojunction, the materialexhibits better carrier mobility, electron transfer, activation energy,and mass diffusion for chemosensing processes than pristine SnO2. It also shows excellent chemosensing properties for TEA,with high response and selectivity at low operating temperatures,while remaining stable and operational for 13 days. Its detectionlimit for TEA, for example, can reach as low as 358 ppb. These attributesmake this material a promising TEA chemosensor for practical applications.