Activated Carbon Obtained from Bamboo: Synthesis, Morphological, Vibrational, and Electrical Properties and Possible Temperature Sensor

Abstract

In order to develop a new temperature sensor based on activated carbon (AC) samples, this work presents the synthesis, basic properties, and temperature sensor characteristics as possible future application. The AC samples are obtained from bamboo as source material via thermal decomposition method, under a controlled nitrogen low-atmosphere, at different carbonization temperatures and activated by using NaOH at 973 K. The basic properties are studied by using SEM, EDS, BET, X-ray diffraction, FTIR, Raman, and electrical techniques. It is found that AC exhibits morphological behavior of particles with vascular characteristics. The structural and vibrational responses suggest graphite oxide domains present in AC. Electrical characterization revealed a two-order of magnitude increase in conductivity, possibly attributed to increased graphite oxide domains produced by desorption of some organic compounds, which benefits development of temperature sensors with negative temperature coefficient (NTC). A possible temperature sensor based on AC is proposed and implemented. The electrical resistivity of AC, as temperature sensor, exhibits a NTC at À4.7%/K, with linear current response varying from 21.1 to 37.2 mA, which is a novelty for a thermistor NTC. These results suggest that AC is an excellent candidate to develop temperature sensors in electronics.

Basic physical properties and potential application of graphene oxide fibers synthesized from rice husk

“…Ismail et al, in 29 , its height depends on the number of the sp 3 carbon atoms of graphene surface and the number of the defects of the graphene 36 , while the G-band is caused by the formation of the stretching vibration sp 2 carbon atoms and represents the graphitized carbon 36 . These bands are characteristic of the Raman spectrum of GO, corresponding to the symmetry A1g and the vibrational mode of E2g, respectively, and overtone bands at high Raman shift of 2622 𝑐𝑚 −1 (2D band), 2875 𝑐𝑚 −1 (D+G band), and 3100 𝑐𝑚 −1 (2D' band), according to data reported in 23 . Broadening of these bands is related with the stacking effect of GO monolayers with edges, defects, and sp 2 regions 23 .…”

“…These bands are characteristic of the Raman spectrum of GO, corresponding to the symmetry A1g and the vibrational mode of E2g, respectively, and overtone bands at high Raman shift of 2622 𝑐𝑚 −1 (2D band), 2875 𝑐𝑚 −1 (D+G band), and 3100 𝑐𝑚 −1 (2D' band), according to data reported in 23 . Broadening of these bands is related with the stacking effect of GO monolayers with edges, defects, and sp 2 regions 23 .…”

“…This aspect promotes RH as an alternative precursor in the production of graphite oxide materials 1,4 . Also, these materials are important in applications, such as green nanocomposites 8 , supercapacitors [11][12][13][14] , conductive materials 15 , adsorbent materials 1,16 , nanomaterials in biomedical applications 17 , batteries 18,19 , electronic devices 20,21 , heater devices 4 , solar cells 22 , and sensors 14,23,24 , among others.…”

Graphene Oxide Fibers: Synthesis Method and Correlation among Compositional, Vibrational, and Electrical Properties

“…The Raman spectra of the GOF samples obtained by varying the T CA from 773 to 1273 K are shown in in 33 , its height depends on the number of the sp 3 carbon atoms of graphene surface and the number of the defects of the graphene 42 , while the G-band is caused by the formation of the stretching vibration sp 2 carbon atoms and represents the graphitized carbon 42 . These bands are characteristic of the Raman spectrum of GO, corresponding to the symmetry A1g and the vibrational mode of E2g, respectively 58 , and overtone bands at high Raman shift of (2D band), (D + G band), and (2D' band), according to data reported in 25 . Broadening of these bands is related with the stacking effect of GO monolayers with edges, defects, and sp 2 regions 25 .…”

“…This aspect promotes RH as an alternative precursor in the production of graphite oxide materials 1,4,5 . Also, these materials are important in applications, such as green nanocomposites 10 , supercapacitors 4,13−16 , conductive materials 17 , adsorbent materials 1,18 , nanomaterials in biomedical applications 9,19,20 , batteries 21,22 , electronic devices 20,23 , solar cells 24 , and sensors 16,25,26 , among others. nitrogen ow through the system and the pump exerts the suction action of the gases present, including the nitrogen.…”