Enhanced sensing performance of the Co3O4 hierarchical nanorods to NH3 gas

ROOM-TEMPERATURE NH3 GAS SENSORS BASED ON HETEROSTRUCTURES PbS/CdS

“…The operating temperature is one of important sensing properties for a gas sensor and a low operating temperature such as room temperature is preferable for its practical applications. Nevertheless, most reports on the NH 3 sensors are focused on the high temperature sensing applications [14][15][16]. The electrical resistance of the sensor was measured in presence and absence of examined gases.…”

High precision NH3 sensing using network nano-sheet Co3O4 arrays based sensor at room temperature

“…The search for new and more effective solid state chemical sensors for monitoring low level concentrations of ammonia in air is of great interest in many fields, including automotive, industrial process monitoring, medical diagnostics and air quality control. One of the mostly used sensing mechanisms for the NH3 is based on resistive sensors using various metal oxide semiconductors [1,2], such as ZnO [3][4], WO3 [5], In2O3 [6][7], ZrO2 [8], V2O5 [9], carbon nanotubes [10][11], Fe2O3 [12] and Co3O4 [13]. Among these, cobalt oxide, Co3O4, has received much research attention due to its high resistance to corrosion, abundant raw material and non-toxicity.…”

“…Among these, cobalt oxide, Co3O4, has received much research attention due to its high resistance to corrosion, abundant raw material and non-toxicity. It is a promising material for applications in Li-ion batteries [14][15][16], catalysts [17,18], and gas sensors [13,[19][20][21][22][23][24][25]. In particular, the oxidative catalytic activity of the Co3O4 is superior [17], thus it can be directly used to design or enhance the gas response, selectivity, and sensing kinetics [13,[19][20][21][22][23][24][25].…”

“…In particular, the oxidative catalytic activity of the Co3O4 is superior [17], thus it can be directly used to design or enhance the gas response, selectivity, and sensing kinetics [13,[19][20][21][22][23][24][25]. However, most reports on the Co3O4 sensors [13,[19][20][21]24,25] were focused on high temperature sensing applications (i.e., up to 300 o C). Up to now, the NH3 sensor based on the Co3O4 operated at room temperature has not been reported.…”

“…Development of novel nanostructured transitional metal oxides with controlled shapes and morphologies has stimulated considerable research interest due to their novel physical and chemical properties and potential wide-range applications [26][27][28]. So far, various morphological nanostructures of Co3O4 have been explored, including nanoparticles [19], nanofiber [20], nanowires [17,[29][30][31], nanotube [15,16], nanobelt [32], nanorods [13,23,24], and nano-sheets [18,33,34] using various methods including thermal oxidation, hydrothermal synthesis, electrospinning and inverse microemulsion. Co3O4 nano-sheets grown directly on substrates should have excellent sensing performance because the interconnected nano-sheets will form a network porous nanoscale system which facilitates a fast and effective gas adsorption onto the entire sensing surface, thus significantly improving sensitivity and reducing the response time.…”