The Atmospheric Pressure Microwave Plasma‐Assisted Synthesis of ZnO/Graphene Hybrid Composite for Nitrite Sensing

Graphene–metal oxide composites are a versatile group of hybrid materials that combine the unique properties of graphene with the functional characteristics of metal oxides. Most synthesis methods of this hybrid material have several limitations, such as the requirement of strong reaction conditions, toxic chemicals and solvents, high temperatures and pressure, and are labor‐intensive. This work focused on the synthesis of the ZnO/graphene hybrid composite using the atmospheric‐pressure microwave plasma method, which advances the field by synthesizing the material in two steps within minutes from sustainable precursors: Cinnamomum Camphora and zinc nitrate. This method eliminates the need for vacuum and thermal conditions, making it economically feasible. Raman and UV–vis spectroscopy confirmed that the composite is graphene and ZnO. The presence of carbon, oxygen and zinc was confirmed using x‐ray photoelectron spectroscopy. The morphology of the material was studied by scanning electron microscopy and transmission electron microscopy. The ZnO particles were found to be spherical in shape and were adsorbed onto the graphene surface. In addition, an electrochemical sensor was fabricated using the ZnO/graphene composite on a screen‐printed electrode for nitrite detection.