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

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Carbon monoxide (CO) detection is critical for the Internet of Things (IoT).
• Metal-organic frameworks (MOFs) offer templating routes for nanomaterial synthesis.
• Cobalt oxide (Co3O4) is a p-type semiconductor with potential gas-sensing applications.

Purpose of the Study:

• To develop a facile method for synthesizing cadmium-doped cobalt oxide nanosheets (Cd-Co3O4 NSs).
• To enhance the CO-sensing performance of Co3O4 by doping with cadmium.
• To investigate the structural and sensing properties of the synthesized materials.

Main Methods:

• A metal-organic frameworks (MOFs)-templated strategy was employed.
• Cadmium (Cd) doping was introduced into Co3O4 nanosheets.
• CO gas sensing performance was evaluated at various concentrations and temperatures.

Main Results:

• Synthesized Cd-Co3O4 NSs exhibited a multihole nanomeshes structure with a high surface area (106.579 m2·g-1).
• The 2 mol% Cd-doped Co3O4 sensor showed enhanced sensitivity (244% to 100 ppm CO at 200°C).
• A low experimental limit of detection (0.5 ppm) and good selectivity, reproducibility, and stability were achieved.

Conclusions:

• Cadmium doping significantly improves the CO-sensing performance of Co3O4 nanosheets.
• The enhanced sensing is attributed to the nanomeshes structure, high surface area, and increased oxygen vacancies.
• This work provides a promising approach for developing advanced gas sensors based on p-type metal oxide semiconductors.