Speaker
Dr
Puleng Mbuyisa
(University of Zululand)
Description
The absorption and desorption properties of ammonia gas on wurzite Zinc Oxide nanorods (ZnO NRs) and Zinc oxide-Carbon nanostructures (ZnO-CNs) hybrid where studies by fast acquisition x-ray photoemission spectroscopy (XPS). Chemiresistor sensors were made out of the ZnO NRs and ZnO-CNs hybrid and the sensors were exposed to ammonia gas at varies concentrations. Ammonia gas was found to chemisorb on the hybrid structure by forming amine groups while on the NRs first physisorbed on the NRs surface and then dissociates by dehydrogenation to form chemisorbed decomposition NHX species. However the chemisorption was beam induced. The hybrid showed a ~ 4.5 higher sensitivity to ammonia as compared to the ZnO NRs sensor but a slower recovery time. The enhanced response and slow desorption of the ZnO-CNs hybrid can be attributed to the strong interaction of the hybrid with ammonia gas i.e the different adsorption surface chemistry of C (chemisorption) and ZnO (physisorption), and also to the increased surface to volume ratio of the CNDs.
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
N/A
Apply to be<br> considered for a student <br> award (Yes / No)?
No
Primary author
Dr
Puleng Mbuyisa
(University of Zululand)
Co-authors
Dr
Cinzia Cepek
(Istituto Officina dei Materiali-CNR, Laboratorio TASC, s.s. 14, km 163.4 I-34149 Trieste, Italy)
Dr
Federica Rigoni
(Interdisciplinary Laboratory for Advanced Materials Physics and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, via dei Musei 41 I-25121 Brescia, Italy)
Dr
Luigi Sangaletti
(Interdisciplinary Laboratory for Advanced Materials Physics and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, via dei Musei 41 I-25121 Brescia, Italy)
Prof.
Muzi Ndwandwe
(University of Zululand)
Dr
Stefania Pagliara
(Interdisciplinary Laboratory for Advanced Materials Physics and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, via dei Musei 41 I-25121 Brescia, Italy)
