A high-sensitivity room-temperature hydrogen gas sensor based on oblique and vertical ZnO nanorod arrays

• Published in: Sensors and actuators. B, Chemical Chemical, 2013-01, Vol.176, p.360-367
• Main Authors: Hassan, J.J., Mahdi, M.A., Chin, C.W., Abu-Hassan, H., Hassan, Z.
• Format: Article
• Language: English
• Subjects: Arrays; catalysts; Gas sensors; hydrogen; Hydrogen gas sensor; hysteresis; microwave treatment; Nanocomposites; Nanomaterials; Nanorod arrays; nanorods; Nanostructure; Oblique nanorods; polyvinyl alcohol; Room temperature; Seeds; Sensors; surface area; temperature; Vertical nanorods; Zinc oxide; ZnO
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2012.09.081

► We synthesized high quality vertically and oblique aligned ZnO nanorods on sapphire substrate. ► We used PVA–Zn(OH)2 nanocomposites as a novel seed materials for microwave assisted-CBD. ► High sensitivity of 500% to H2 was examined at RT for ZnO nanorod arrays. ► The oblique/vertical nanorods were the key factors for the high sensitivity. The high surface area to volume ratio, the networks connections of vertically and oblique nanorod arrays, and the absence of seed layer, were the key factors responsible for the high sensitivity of ZnO nanorod arrays based hydrogen sensor at room temperature. Arrays of vertical and oblique zinc oxide nanorods were grown on a c-plane sapphire substrate by microwave-assisted chemical bath deposition. Polyvinyl alcohol (PVA)–Zn(OH)2 nanocomposites were used as a novel seed material to seed the sapphire substrate prior to the growth of the ZnO nanorods. The hydrogen sensing capabilities of the ZnO nanorod arrays, without the use of a metal catalyst, were investigated at room temperature. The rods exhibited excellent sensitivity, of 500%, in the presence of 1000ppm of H2 while consuming an ultralow level of power (