Novel ozone gas sensor based on ZnO nanostructures grown by the microwave-assisted hydrothermal route

Abstract

Good quality ZnO nanostructures were obtained by the microwave-assisted hydrothermal synthesis, at low reaction temperatures, using zinc acetate as the starting precursor. X-ray diffraction confirmed the crystallinity of the ZnO nanostructures, which resulted free of impurities. Field emission gun scanning electron microscopy analysis revealed that the ZnO nanostructures crystallized at 120 1C were more homogeneous and had a constant diameter along the entire wire length, exhibiting an ideal defect density that favors the gas sensing response. A new ozone gas sensor based on these nanostructures was evaluated at low exposure times (15 s) by recording the change in the film resistance. The ZnO nanostructures showed good sensitivity even at low ozone concentration (100 ppb), and fast response and short recovery time at 200 1C, demonstrating great potential for a variety of applications. Two main effects were observed: the first one is intrinsic to that of the sample, while the second is a consequence of the surface and interface complex cluster defects, which produce extrinsic defects.

One-step approach for preparing ozone gas sensors based on hierarchical NiCo2O4 structures

“…A low detection level of 28 ppb was achieved at the temperature with optimized performance, below the values in the recent literature. 34,62,63 The range for detection was from 28-165 ppb, with good sensitivity, selectivity and fast response ($32 s) and recovery time ($60 s). The mechanism of detection was found to be based on adsorption of ozone molecules on the NiCo 2 O 4 surface, which creates a layer of holes that affect the conductivity, as in a p-type semiconductor.…”

Property of Zinc Oxide (Zno) Nanostructures Potential for Biomedical System and Its Common Growth Mechanism

“…Also, ZnO is transparent to visible light and can be made highly conductive by doping [5][6][7]. Moreover, due to its unique characteristics of crystal structure, the lack of a symmetry center in wurtzite structure and large electromechanical coupling result in strong piezoelectric and pyroelectric properties and show predominant applications in mechanical actuators and piezoelectric sensors [8][9][10], chemical sensors [11,12] and solar cells [13,14].…”

A Review of Microwave Synthesis of Zinc Oxide Nanomaterials: Reactants, Process Parameters and Morphologies

“…The most popular reactants being hydroxide anion precursor chemicals “OH − ” used for the ZnO synthesis according to the data derived from the literature review [ 506 , 507 , 508 , 509 , 510 , 511 , 512 , 513 , 514 , 515 , 516 , 517 , 518 , 519 , 520 , 521 , 522 , 523 , 524 , 525 , 526 , 527 , 528 , 529 , 530 , 531 , 532 , 533 , 534 , 535 , 536 , 537 , 538 , 539 , 540 , 541 , 542 , 543 , 544 , 545 , 546 , 547 , 548 , 549 , 550 , 551 , 552 , 553 ,…”