Gas sensors based on ultrathin porous Co₃O₄ nanosheets to detect acetone at low temperature

Abstract

Using a facile two-step process, including a hydrothermal technique and subsequently controlled annealing of the precursor, ultrathin porous Co 3 O 4 nanosheets can be synthesized. The gas sensor based on the porous Co 3 O 4 nanosheets shows a superior acetone gas-sensing performance at a low operating temperature of 150 C. The gas response to 100 ppm acetone reached 11.4, and exhibited good reproducibility. In addition, the detection limit of the Co 3 O 4 nanosheet sensor is lower than 1.8 ppm, which is the diagnostic criteria exhaled from diabetes. What's more, the sensor exhibited good stability when tested over 2 months. The outstanding gas-sensing properties were explained by a typical p-type semiconductor behavior with an ultrathin porosity structure as well as a large specific surface area of Co 3 O 4 nanosheets.

Combustion of lean methane over Co3O4 catalysts prepared with different cobalt precursors

“…[14][15][16][17] Among these candidate metal oxides, cobalt-based oxides are well known because of the structured and electronic properties of spinel type oxides with variable valence states (Co 2+ /Co 3+ ) as well as the lower bonding energy of Co-O bonds, which exhibit high activity for catalytic combustion of lean methane. 18 Therefore, the cobalt-based catalysts have extensive applications in sensors, 19 lithium-ion batteries, 20 magnetic materials, 21 pigments 22 and solar cells, 23 which also show high activity for the oxidation of CH 4 , CO and VOCs due to their high redox ability and strong oxygen mobility. 24,25 It is well known that the catalytic performance of catalysts is closely related to its structure and properties, which strongly depends on the catalyst synthesis method and the types of catalyst precursors.…”

Gas sensor properties of nanopore-bearing Co3O4particles containing Pt or Pd particles

“…However, to accurately detect a specific gas within respiratory gas, an improved selectivity was required. In this context, it has been reported that the presence of nanopores in the cobalt oxide particles in addition to control over the particle shape will increase both the sensitivity and selectivity of such a system [9][10][11].…”

Two‐Dimensional Nanostructured Materials for Gas Sensing

“…In addition to ZnO nanosheets, a number of other 2D metal oxide nanostructures have been tested for chemical gas sensors, such as SnO 2 , CuO, NiO, In 2 O 3 , WO 3 , and Co 3 O 4 , which exhibited good sensing properties to a variety of analytes. Zhang and Yin reported the synthesis of SnO 2 nanosheets via a simple, cost‐effective and environment‐friendly hydrothermal method at 90 °C, combined with post calcination.…”