Au@NiO core-shell nanoparticles as a p-type gas sensor: Novel synthesis, characterization, and their gas sensing properties with sensing mechanism
Type
ArticleAuthors
Majhi, Sanjit Manohar
Naik, Gautam Kumar
Lee, Hu-Jun
Song, Ho-Geun
Lee, Cheul-Ro
Lee, In-Hwan
Yu, Yeon-Tae
KAUST Department
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) DivisionElectrical Engineering Program
Date
2018-04-25Online Publication Date
2018-04-25Print Publication Date
2018-09Permanent link to this record
http://hdl.handle.net/10754/627840
Metadata
Show full item recordAbstract
In this work, Au@NiO core-shell nanoparticles (C-S NPs) as a p-type gas sensing material was synthesized by a facile wet-chemical method, and evaluated their gas sensing properties as compared to the pristine NiO NPs gas sensors. Transmission electron microscope (TEM) results exhibited the well-dispersed formation of Au@NiO C-S NPs having the total size of 70–120 nm and NiO shells having 30–50 nm thickness. The C-S morphology as well as the overall particle sizes are unchanged even at 500 °C. The gas sensing result reveals that the response of Au@NiO C-S NPs gas sensor is higher than pristine NiO NPs gas sensor for 100 ppm of ethanol at 200 °C operating temperature. The baseline resistance in the air for Au@NiO C-S NPs sensor is lowered as compared to pristine NiO NPs, which is due to the increased number of holes as charge carriers in Au@NiO C-S NPs. The high response of Au@NiO core-shell NPs as compared to pristine NiO NPs is attributed to electronic and chemical sensitization effects of Au. In Au@NiO C-S structure, the contact between metal (Au) and semiconductor (NiO) formed a Schottky junction since Au metal acted as electron acceptor, a withdrawal of electrons from NiO by Au metal core leaved behind number of holes as charge carriers in Au@NiO C-S NPs. Therefore, the baseline resistance of Au@NiO C-S NPs greatly decreased than pristine NiO NPs, as a result the Au@NiO C-S NPs showed higher response. On the other hand, in chemical sensitization effect, Au NPs catalyzed to dissociate O2 molecules into ionic species. This work will give some clue to the researchers for the further development of p-type based C-S NPs sensors.Citation
Majhi SM, Naik GK, Lee H-J, Song H-G, Lee C-R, et al. (2018) Au@NiO core-shell nanoparticles as a p-type gas sensor: Novel synthesis, characterization, and their gas sensing properties with sensing mechanism. Sensors and Actuators B: Chemical 268: 223–231. Available: http://dx.doi.org/10.1016/j.snb.2018.04.119.Sponsors
This work was supported by (1) BK21 plus program from the Ministry of Education and Human Resource Development, (2) National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (BRL No. 2015042417, 2016R1A2B4014090), (3) Business for Academic-industrial Cooperative establishments funded by Korea Small and Medium Business Administration in 2016 (Grant No. C0396231), and (4) Centre for University Research Facility (CURF), CBNU, and Korean Basic Science Institute (KBSI), CBNU branch are acknowledged for the analysis of TEM and HR-TEM, respectively.Publisher
Elsevier BVAdditional Links
http://www.sciencedirect.com/science/article/pii/S0925400518308244ae974a485f413a2113503eed53cd6c53
10.1016/j.snb.2018.04.119