Graphene oxide nanosheets modified with TiO2 nanoparticles for highly sensitive NH3 detection at room temperature

In this work, graphene oxide (GO) nanosheets modified with TiO 2 nanoparticles were prepared by a simple solution ultrasonication method. The GO/TiO 2 nanocomposites were successfully synthesized by in-situ oxidation of Ti 3 C 2 T x nanosheets on the surface of GO nanosheets . It is revealed that spindle-shaped TiO 2 nanoparticles are uniformly distributed on the GO nanosheets, which will provide more active sites for NH 3 adsorption. The response of NH 3 sensor based on GO/TiO 2 nanocomposites to 100 ppm NH 3 at room temperature is approximately twice that of pure GO, which may be attributed to its unique structure and GO/TiO 2 heterojunction . The GO/TiO 2 sensors also demonstrated good stability, ideal repeatability, great selectivity , and a quick response/recovery time of 13/33 s. Lastly, density-functional theory (DFT) was used to examine the adsorption behavior and charge transfer capacity between NH 3 molecules and the materials. The results indicate that the GO/TiO 2 nanocomposites are potentially useful materials for highly sensitive NH 3 detection at room temperature.