Optimization of a zinc oxide urchin-like structure for high-performance gas sensing

Abstract

Zinc oxide (ZnO) hollow hemisphere (HS) and urchin-like (UL) structures were fabricated and examined for application to a gas sensor. Films of hollow ZnO-HS arrays floating over substrates were synthesized via Zn sputtering onto the template of a polystyrene sphere array followed by oxidation. Growing ZnO nanorods upon HS surfaces via a hydrothermal method formed hollow ZnO-UL structures. The thicknesses of the HS films and the lengths of nanorods in the UL structures were varied to obtain the maximum response to NO gas. Both sensor structures showed a sensing of tens of parts per billion of levels of NO concentrations with good response and gas selectivity. The highest response was realized through the thinness and the open porosity of the structures. The surface depletion determined the sensor response signal for the sensor geometry with the highest response.

Ultrasensitive and low detection limit of acetone gas sensor based on W-doped NiO hierarchical nanostructure

“…Resistive gas sensors based on metal oxide semiconductors such as SnO 2 [1,2], ZnO [3,4], TiO 2 [5,6], WO 3 [7][8][9][10][11][12], In 2 O 3 [13,14], α-Fe 2 O 3 [15], and NiO [16] occupy the significant positions in the field of gas sensors for monitoring and detecting inflammable, explosive, or toxic gases due to the advantages of low cost, simple operation and portability. Extensive research efforts have been committed to develop high-performance gas sensors with high sensitivity and low detection limit [17].…”

“…shows the responses of the sensor based on the 4.0 at% W-doped NiO to 100 ppm various tested gases including acetone, ethanol, methanol, benzene, CO, NH3 , and formaldehyde at different operating temperature. The selectivity of acetone was improved with raising the operating temperature from 200 to 275 °C.…”

Gigantically enhanced NO sensing properties of WO3/SnO2 double layer sensors with Pd decoration

“…Noticeably, the Pt/S/W(Pd) sensor exhibited the best sensing performance among these five sensors, with the response 10 times larger than and the recovery time only one tenth of that of the Pt/W sensor. For comparison, the responses, response times and the recovery times of representative NO gas sensors reported in literatures were normalized according to the definition of this work, and also listed in Table 2 [28,[34][35][36][37]. Among all the sensors listed in Table 2, the Pt/S/W(Pd) sensor has the fastest response and recovery, and the response is also one of the highest.…”

Enhancement of Dye-Sensitized Solar Cell Efficiency by Spherical Voids in Nanocrystalline ZnO Electrodes

“…ZnO powder with < 100 nm particle size, was used to fabricate the anode. Polystyrene(PS) spheres were synthesized in accordance with the previous works, 3,16) in which the diameter of PS spheres was controlled by changing the weight of reagents as shown in Table 1.…”