title: Sprayed zinc oxide films: Ultra-violet light-induced reversible surface wettability and platinum-sensitization-assisted improved liquefied petroleum gas response.
abstract: We report the rapid (superhydrophobic to superhydrophilic) transition property and improvement in the liquefied petroleum gas (LPG) sensing response of zinc oxide (ZnO) nanorods (NRs) on UV-irradiation and platinum (Pt) surface sensitization, respectively. The morphological evolution of ZnO NRs is evidenced from the field emission scanning electron microscope and atomic force microscope digital images and for the structural elucidation X-ray diffraction pattern is used. Elemental survey mapping is obtained from energy dispersive X-ray analysis spectrum. The optical properties have been studied by UV-Visible and photoluminescence spectroscopy measurements. The rapid (120sec) conversion of superhydrophobic (154°) ZnO NRs film to superhydrophilic (7°) is obtained under UV light illumination and the superhydrophobicity is regained by storing sample in dark. The mechanism for switching wettability behavior of ZnO NRs has thoroughly been discussed. In second phase, Pt-sensitized ZnO NRs film has demonstrated considerable gas sensitivity at 260ppm concentration of LPG. At 623K operating temperature, the maximum LPG response of 58% and the response time of 49sec for 1040ppm LPG concentration of Pt- sensitized ZnO NRs film are obtained. This higher LPG response of Pt-sensitized ZnO NRs film over pristine is primarily due to electronic effect and catalytic effect (spill-over effect) caused by an additional of Pt on ZnO NRs film surface.
authors.affiliation: Department of Applied Physics, Thin Films Laboratory, Defence Institute of Advanced Technology, Girinagar, Pune 411025, Maharashtra, India; School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded, India. Electronic address: umesh.nakate@gmail.com.
authors.forename: Umesh T
authors.initials: UT
authors.lastname: Nakate
authors.affiliation: Defence Bioengineering and Electromedical Laboratory, Bangalore 560 093, India.
authors.forename: Pramila
authors.initials: P
authors.lastname: Patil
authors.affiliation: Department of Physics, Thin Films Physics Laboratory, Shivaji University, Kolhapur 416004, India.
authors.forename: R N
authors.initials: RN
authors.lastname: Bulakhe
authors.affiliation: Department of Physics, Thin Films Physics Laboratory, Shivaji University, Kolhapur 416004, India.
authors.forename: C D
authors.initials: CD
authors.lastname: Lokhande
authors.affiliation: Department of Applied Physics, Thin Films Laboratory, Defence Institute of Advanced Technology, Girinagar, Pune 411025, Maharashtra, India.
authors.forename: Sangeeta N
authors.initials: SN
authors.lastname: Kale
authors.affiliation: Department of Chemistry, College of Science, Bld-5, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Mu
authors.initials: M
authors.lastname: Naushad
authors.affiliation: Department of Chemistry, College of Science, Bld-5, King Saud University, Riyadh, Saudi Arabia; School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded, India. Electronic address: rajarammane70@srtmun.ac.in.
authors.forename: Rajaram S
authors.initials: RS
authors.lastname: Mane
keywords: LPG response; Pt-surface sensitization; Superhydrophobic-superhydrophilic; UV light; ZnO nanorods