Graphitization and Raman Measurement Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Download our mobile app to listen on the go

Get App

Questions and Answers

What is the nitrogen content of the resulting carbon sheets?

3.06 wt%

What is the specific surface area of the resulting carbon sheets?

1997.5 m2 g$^{-1}$

What is the specific capacitance of the NACS electrode?

312 F g$^{-1}$

What is the mass ratio of glucose to melamine in the synthesis of N-doped carbon sheets?

1:1 Signup and view all the answers

What is the purpose of the chemical blowing process?

To form sheet-like precursors and introduce nitrogen element. Signup and view all the answers

What happens to the sheet-like precursors as the temperature increases?

They are further carbonized to form NCS. Signup and view all the answers

What is the thickness of NACS?

Several 10 nm. Signup and view all the answers

What is the speciﬁc surface area of NACS?

1997.5 m2 g^-1. Signup and view all the answers

What method was used to estimate the pore size distributions?

density functional theory (DFT) method Signup and view all the answers

What type of microscope was used to observe the morphologies?

FEI Tecnai G2 20 transmission electron microscope (TEM) Signup and view all the answers

What is the formula for calculating the specific energy density (E) for a symmetric supercapacitor?

E = \frac{1},{2}CV^2 Signup and view all the answers

What is the formula for calculating the specific power density (P)?

P = Et Signup and view all the answers

What is the maximum specific capacitance of the material at a current density of 0.5 A g^{-1}?

312 F g^{-1} Signup and view all the answers

What is the specific capacitance of the material at a current density of 30 A g^{-1}?

246 F g^{-1} Signup and view all the answers

What is the retention rate of the cycle stability after 4000 galvanostatic charge-discharge cycles?

91.3% Signup and view all the answers

What is the maximum energy density of the assembled NACS-based symmetric capacitor?

20.2 Wh kg^{-1} Signup and view all the answers

What is the purpose of the study?

The purpose of the study is to synthesize N-doped activated carbon sheets for supercapacitor application. Signup and view all the answers

What is the method used to synthesize the N-doped activated carbon sheets?

The N-doped activated carbon sheets are synthesized using glucose as a carbon source via melamine-assisted chemical blowing and sequent KOH-activation method. Signup and view all the answers

What are the properties of the obtained carbon material?

The obtained carbon material possesses a sheet-like morphology with ultrathin thickness, hierarchical micro/mesoporous structure, high specific surface area (up to 1997.5 m^2 g^-1), and high pore volume (0.94 cm^3 g^-1). Signup and view all the answers

What is the nitrogen content of the NACS material?

The nitrogen content of the NACS material is 3. Signup and view all the answers

What is the characteristic peak observed in the Raman spectra?

The characteristic peak observed in the Raman spectra is at approximately 1356 cm^{-1}, corresponding to the D-band. Signup and view all the answers

What does the peak at about 1596 cm^{-1} in the Raman spectra indicate?

The peak at about 1596 cm^{-1} in the Raman spectra indicates the presence of the G-band, which denotes the ordered graphite lattice of carbon material. Signup and view all the answers

What is the calculated intensity ratio of D and G bands (ID/IG)?

The calculated intensity ratio of D and G bands (ID/IG) is 0.92, indicating a low crystallinity of the obtained NACS. Signup and view all the answers

What are the four different types of nitrogen functionalities observed in the high resolution N1s spectrum of NACS?

The four different types of nitrogen functionalities observed in the high resolution N1s spectrum of NACS are pyridinic-N (N6) at 398.3 eV, pyrrolic-N (N-5) at 400.2 eV, quaternary-N (N-Q) at 401.4 eV, and pyridine-N-oxide (N-X) at 403.0 eV. Signup and view all the answers

What is the speciﬁc capacitance of NACS at 0.5 A g^-1?

312 F g^-1 Signup and view all the answers

What is the speciﬁc capacitance of NACS at a high current density of 30 A g^-1?

246 F g^-1 Signup and view all the answers

What are the reasons for the high speciﬁc capacitance and excellent rate performance of NACS?

<ol> <li>The sheet-like morphology provides a large exposed area to electrolytes and a short diffusion distance for electrolyte ions into the inner pore walls. 2) Hierarchical micro/mesoporous structure with high speciﬁc surface area, microporous volume and uniform pore size distribution could accelerate ion transport process within the pore channels and provide abundant inner surface regions for ion accumulation. 3) Doping nitrogen groups don't only increase the surface wetting characters, but also improve the conductivity of carbon materials and introduce extra pseudocapacitance, thus further enhancing the capacity performance.</li> </ol> Signup and view all the answers

What are the advantages of the NACS compared to AC and NCS materials?

The speciﬁc capacitances of NACS at any current densities are much higher than those of AC and NCS materials. Signup and view all the answers

What does the high speciﬁc capacitance and excellent rate performance of NACS demonstrate?

The high speciﬁc capacitance and excellent rate performance of NACS demonstrate its ability to maintain a high capacitance even at high current densities. Signup and view all the answers

What is the effect of the chemical blowing agent percentage on the ele?

The effect of the chemical blowing agent percentage on the ele is not mentioned in the given text. Signup and view all the answers

Flashcards are hidden until you start studying