Highly sensitive SnO2 nanofiber chemiresistors with a low optimal operating temperature: synergistic effect of Cu2+/Au co-doping

2014 ◽  
Vol 2 (33) ◽  
pp. 13655-13660 ◽  
Author(s):  
Zhenyu Li ◽  
Xungai Wang ◽  
Tong Lin

SnO2 nanofibers after being co-doped with Cu2+ and Au show considerably enhanced sensing performances at an unexpectedly decreased operating temperature and a synergistic effect occurs when the two dopants are introduced together.

2011 ◽  
Vol 197-198 ◽  
pp. 891-894 ◽  
Author(s):  
Cheng Zhi Jiang ◽  
Xu Dong Lu

Pure TiO2, Eu3+and Sm3+co-doping TiO2composite nanoparticles have been prepared by sol-gel method and characterized by the techniques such as XRD, SEM and DRS. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate their photocatalytic activity. The matrix distortion of TiO2nano-particles increases after co-doping of Eu3+and Sm3+and a blue-shift of the absorption profile are clearly observed. The results show that co-doping of Eu3+and Sm3+inhibits the phase transformation of TiO2from anatase to rutile, decreases the diameter of TiO2nano-particles and significantly enhance the photocatalytic activity of TiO2. The Eu3+and Sm3+co-doped into TiO2nano-particles exert a synergistic effect on their photocatalytic activity.


2018 ◽  
Vol 6 (27) ◽  
pp. 13062-13074 ◽  
Author(s):  
Jiangnan Huang ◽  
Yuhang Li ◽  
Yonghai Cao ◽  
Feng Peng ◽  
Yonggang Cao ◽  
...  

F and N co-doped magnetic nanocarbons as adsorbents for environmental remediation have been demonstrated for the first time with high efficiency.


2018 ◽  
Vol 42 (2) ◽  
pp. 1105-1114 ◽  
Author(s):  
Mahima Khandelwal ◽  
Yuanyuan Li ◽  
Seung Hyun Hur ◽  
Jin Suk Chung

The synergistic effect of heteroatom co-doping and triethanolamine functionalization on reduced graphene oxide resulted in impressive electrochemical features.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Z. Moradi ◽  
M. Farsi

AbstractThe purpose of presented research is the mathematical simulation and sensitivity analysis of ethylene dichloride synthesis (EDC) through direct chlorination of ethylene in a bubble column reactor at steady state condition. In the first step, the reactor is heterogeneously simulated based on the energy and mass balance equations by coupling the mass and energy, kinetic, equilibrium, and population balance models. In the considered process, the gaseous ethylene and chlorine are dispersed and dissolved in the liquid medium and converted to EDC at the presence of a homogeneous catalyst. The population balance model is applied to calculate the heat and mass transfer area along the reactor. To investigate the accuracy of established model, the results of simulation are compared with the plant data. It is confirmed that temperature, pressure, rate of mass transfer, breakage, and coalescence phenomena change the bubble diameter and distribution in the chlorination reactor. In the second step, the effects of operating pressure and temperature on the EDC production rate are investigated by the developed model. In the third step, considering EDC production rate as the cost function the optimal operating temperature of reactor is developed at steady state condition. Based on the obtained results, the optimal operating temperature is 357 K and EDC production at the optimal condition is 23.79 mol s−1.


Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 35 ◽  
Author(s):  
Kechuang Wan ◽  
Jialin Yang ◽  
Ding Wang ◽  
Xianying Wang

In this work, we reported a formaldehyde (HCHO) gas sensor with highly sensitive and selective gas-sensing performance at low operating temperature based on graphene oxide (GO)@SnO2 nanofiber/nanosheets (NF/NSs) nanocomposites. Hierarchical SnO2 NF/NSs coated with GO nanosheets showed enhanced sensing performance for HCHO gas, especially at low operating temperature. A series of characterization methods, including X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) were used to characterize their microstructures, morphologies, compositions, surface areas and so on. The sensing performance of GO@SnO2 NF/NSs nanocomposites was optimized by adjusting the loading amount of GO ranging from 0.25% to 1.25%. The results showed the optimum loading amount of 1% GO in GO@SnO2 NF/NSs nanocomposites not only exhibited the highest sensitivity value (Ra/Rg = 280 to 100 ppm HCHO gas) but also lowered the optimum operation temperature from 120 °C to 60 °C. The response value was about 4.5 times higher than that of pure hierarchical SnO2 NF/NSs (Ra/Rg = 64 to 100 ppm). GO@SnO2 NF/NSs nanocomposites showed lower detection limit down to 0.25 ppm HCHO and excellent selectivity against interfering gases (ethanol (C2H5OH), acetone (CH3COCH3), methanol (CH3OH), ammonia (NH3), methylbenzene (C7H8), benzene (C6H6) and water (H2O)). The enhanced sensing performance for HCHO was mainly ascribed to the high specific surface area, suitable electron transfer channels and the synergistic effect of the SnO2 NF/NSs and GO nanosheets network.


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