scholarly journals Hydrothermal Synthesis of SnO2 Nanoneedle-Anchored NiO Microsphere and its Gas Sensing Performances

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1015 ◽  
Author(s):  
Zhijie Wei ◽  
Qu Zhou ◽  
Jingxuan Wang ◽  
Zhaorui Lu ◽  
Lingna Xu ◽  
...  

In this study, we reported a successful synthesis of a nanocomposite based on SnO2 nanoneedles anchored to NiO microsphere by a simple two-step hydrothermal route. The results show that the SnO2/NiO nanocomposite-based sensor exhibits more prominent performances than the pristine NiO microsphere to NO2 such as larger responses and more outstanding repeatability. The improved properties are mainly attributed to the p–n heterojunctions formed at the SnO2–NiO interface, leading to the change of potential barrier height and the enlargement of the depletion layer. Besides, the novel and unique nanostructure provides large and effective areas for the surface reaction. In addition, a plausible growth mechanism and the enhanced sensing mechanism were proposed to further discuss the special nanostructure which will benefit the exploration of high-performance sensors.

RSC Advances ◽  
2017 ◽  
Vol 7 (61) ◽  
pp. 38714-38724 ◽  
Author(s):  
Rajneesh Kumar Mishra ◽  
G. Murali ◽  
Tae-Hyung Kim ◽  
Jee Hun Kim ◽  
Young Jin Lim ◽  
...  

Here, we demonstrated the formation of active sites O2− and O− on the surface of nanocube In2O3@RGO heterostructure, gas sensing mechanisms and fluctuations in potential barrier height before and after insertion of acetone and formaldehyde.


2004 ◽  
Vol 99 (1) ◽  
pp. 189-196 ◽  
Author(s):  
V. N. Vasyukov ◽  
A. D. Prokhorov ◽  
V. P. D’yakonov ◽  
H. Szymczak

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3294
Author(s):  
Jakkree Boonlakhorn ◽  
Jedsada Manyam ◽  
Pornjuk Srepusharawoot ◽  
Sriprajak Krongsuk ◽  
Prasit Thongbai

The effects of charge compensation on dielectric and electrical properties of CaCu3Ti4-x(Al1/2Ta1/4Nb1/4)xO12 ceramics (x = 0−0.05) prepared by a solid-state reaction method were studied based on the configuration of defect dipoles. A single phase of CaCu3Ti4O12 was observed in all ceramics with a slight change in lattice parameters. The mean grain size of CaCu3Ti4-x(Al1/2Ta1/4Nb1/4)xO12 ceramics was slightly smaller than that of the undoped ceramic. The dielectric loss tangent can be reduced by a factor of 13 (tanδ ~0.017), while the dielectric permittivity was higher than 104 over a wide frequency range. Impedance spectroscopy showed that the significant decrease in tanδ was attributed to the highly increased resistance of the grain boundary by two orders of magnitude. The DFT calculation showed that the preferential sites of Al and Nb/Ta were closed together in the Ti sites, forming self-charge compensation, and resulting in the enhanced potential barrier height at the grain boundary. Therefore, the improved dielectric properties of CaCu3Ti4-x(Al1/2Ta1/4Nb1/4)xO12 ceramics associated with the enhanced electrical properties of grain boundaries. In addition, the non-Ohmic properties were also improved. Characterization of the grain boundaries under a DC bias showed the reduction of potential barrier height at the grain boundary. The overall results indicated that the origin of the colossal dielectric properties was caused by the internal barrier layer capacitor structure, in which the Schottky barriers at the grain boundaries were formed.


1990 ◽  
Vol 29 (Part 2, No. 11) ◽  
pp. L1977-L1980 ◽  
Author(s):  
Takeshi Takagi ◽  
Fumio Koyama ◽  
Kenichi Iga

2007 ◽  
Vol 76 (21) ◽  
Author(s):  
E. S. Cruz de Gracia ◽  
L. S. Dorneles ◽  
L. F. Schelp ◽  
S. R. Teixeira ◽  
M. N. Baibich

1997 ◽  
Vol 11 (09n10) ◽  
pp. 441-451 ◽  
Author(s):  
Paulo César Miranda Machado ◽  
Francisco A. P. Osório ◽  
A. Newton Borges

The effects of the potential barrier height on the collective excitations of a electron gas confined in a GaAs-AlxGa1-xAs quantum wire of rectangular cross-section are investigated theoretically. For several potential barrier heights, we calculated the plasmon energy, structure factor and pair-correlation function, within the Random-Phase Approximation regime, considering a three-subband model with only the lowest subband populated by electrons. We verified that the intersubband plasmon is more sensitive to the potential barrier height variation than the intrasubband plasmon. We also observed that the confining potential effect decreases with the increasing of the wire-width.


2016 ◽  
Vol 18 (9) ◽  
pp. 6901-6912 ◽  
Author(s):  
Hailiang Dong ◽  
Jing Sun ◽  
Shufang Ma ◽  
Jian Liang ◽  
Taiping Lu ◽  
...  

The effect of the height of the potential barrier on the confined level of carrier transport was studied in InGaAs/GaAsP MQWs.


Sign in / Sign up

Export Citation Format

Share Document