TY - JOUR
T1 - Super-Nernstian pH sensors based on WO3 nanosheets
AU - Kuo, Chao Yin
AU - Wang, Shui Jinn
AU - Ko, Rong Ming
AU - Tseng, Hung Hao
N1 - Funding Information:
This work was supported by the Ministry of Science and Technology (MOST), Taiwan, under contract Nos. MOST 105-2221-E-006-196-MY3 and MOST 104-2221-E-006-130-MY3. The authors would like to thank the Instrument Center, National Cheng Kung University, Taiwan, for use of its high-resolution scanning electron microscope (Hitachi SU8000) and technical support.
Publisher Copyright:
© 2018 The Japan Society of Applied Physics.
PY - 2018/4
Y1 - 2018/4
N2 - The effects of the surface morphology of hydrothermally grown WO3 nanosheets (NSs) and sputtering WO3 film on the performance of pH sensing electrodes are presented and compared in the pH range of 2-12. Using a separated electrode of an extended-gate field-effect transistor (EGFET) configuration, the WO3 nanosheet (NS) pH sensor shows a sensitivity of 63.37 mV/pH, a good linearity of 0.9973, a low voltage hysteresis of 4.79 mV, and a low drift rate of 3.18 mV/h. In contrast, the film-type one shows a typical sensitivity of only 50.08mV/pH and a linearity of 0.9932. The super-Nernstian response could be attributed to the significant increase in the number of surface ion adsorption sites of the NS structure and the occurrence of local electric field enhancement over the sharp edges and corners of WO3 NSs.
AB - The effects of the surface morphology of hydrothermally grown WO3 nanosheets (NSs) and sputtering WO3 film on the performance of pH sensing electrodes are presented and compared in the pH range of 2-12. Using a separated electrode of an extended-gate field-effect transistor (EGFET) configuration, the WO3 nanosheet (NS) pH sensor shows a sensitivity of 63.37 mV/pH, a good linearity of 0.9973, a low voltage hysteresis of 4.79 mV, and a low drift rate of 3.18 mV/h. In contrast, the film-type one shows a typical sensitivity of only 50.08mV/pH and a linearity of 0.9932. The super-Nernstian response could be attributed to the significant increase in the number of surface ion adsorption sites of the NS structure and the occurrence of local electric field enhancement over the sharp edges and corners of WO3 NSs.
UR - http://www.scopus.com/inward/record.url?scp=85044475998&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85044475998&partnerID=8YFLogxK
U2 - 10.7567/JJAP.57.04FM09
DO - 10.7567/JJAP.57.04FM09
M3 - Article
AN - SCOPUS:85044475998
SN - 0021-4922
VL - 57
JO - Japanese journal of applied physics
JF - Japanese journal of applied physics
IS - 4
M1 - 04FM09
ER -