In/Cu Co-Doped Porous Co₃O₄ Nanosheets for Enhanced Xylene Detection

Bimetallic doping of semiconductor metal oxides is increasingly recognized as a research hotspot in the field of semiconductor materials, attributed to its unique synergistic effects that facilitate multidimensional modulation of properties. In this study, In/Cu co-doped porous Co3O4 nanosheet materials are created utilizing an uncomplicated hydrothermal approach. The crystal structure, morphology, and elemental composition of the synthesized materials are extensively analyzed using a range of techniques, including XRD, XPS, SEM, TEM, energy-dispersive spectrometry (EDS), and nitrogen adsorption-desorption. The findings reveal that integrating In/Cu metal ions into the Co3O4 lattice results in decreased crystal size, enhanced specific surface area, and increased oxygen defects, compared to the pure Co3O4. Notably, the 0.9 at% In/Cu co-doped Co3O4 sensor demonstrates an exceptional xylene sensing response of 210.15–100 ppm at 160 °C. This sensor, in comparison to the Co3O4 metal oxide semiconductor gas sensor, demonstrates superior temporal characteristics during the analysis of 100 ppm of xylene at 160 °C, while concurrently maintaining an exceptionally low detection threshold of 500 ppb. The sensor also exhibits outstanding repeatability, selectivity, and stability. Analysis of the detection mechanism indicates that the enhanced performance of the In/Cu co-doped Co3O4 sensor is primarily due to the formation of dispersed porous nanosheets and the synergistic interaction between the In and Cu ions.