Surface modification of Co3O4 nanosheets through Cd-doping for enhanced CO sensing performance

Abstract The detection of hazardous CO gas is an important research content in the domain of the Internet of Things (IoT). Herein, we introduced a facile metal-organic frameworks (MOFs)-templated strategy to synthesize Cd-doped Co 3 O 4 nanosheets (Cd-Co 3 O 4 NSs) aimed at boosting the CO-sensing performance. The synthesized Cd-Co 3 O 4 NSs feature a multihole nanomeshes structure and a large specific surface area (106.579 m 2 ·g -1 ), which endows the sensing materials with favorable gas diffusion and interaction ability. Furthermore, compared with unadulterated Co 3 O 4 , the 2 mol % Cd-doped Co 3 O 4 (2% Cd-Co 3 O 4 ) sensor exhibits enhanced sensitivity (244%) to 100 ppm CO at 200 °C and a comparatively low experimental limit of detection (0.5 ppm/experimental value). The 2% Cd-Co 3 O 4 NSs show good selectivity, reproducibility, and long-term stability. The improved CO sensitivity signal is probably owing to the stable nanomeshes construction, high surface area, and rich oxygen vacancies caused by cadmium doping. This study presents a facile avenue to promote the sensing performance of p-type metal oxide semiconductors by enhancing the surface activity of Co 3 O 4 combined with morphology control and component regulation. Graphical Abstract