Parametric study of waste chicken fat catalytic chemical vapour deposition for controlled synthesis of vertically aligned carbon nanotubes

Figures & data

Figure 1. FESEM images of CNTs synthesised at precursor vaporisation temperatures of (a) 370, (b) 420, (c)–(d) 470, (e)–(f) 520, (g)–(h) 570, (i)–(j) 670 and (k)–(l) 770°C at different magnification.

Figure 2. Micro-Raman spectra of the samples synthesised at different vaporisation temperatures of 370–770°C with enlarged spectrum of 2D peak.

Table 1. The I_D/I_G ratio of the CNTs samples synthesised at different vaporisation temperatures of 370–770°C

Sample (°C)	D peak (cm^−1)	G peak (cm^−1)	G′ width (cm^−1)	ID/IG ratio
370	1,370.6	1,581.2	73.0	0.73
420	1,346.8	1,578.2	90.0	0.66
470	1,344.7	1,576.1	66.3	0.60
520	1,350.0	1,579.2	69.7	0.52
570	1,348.9	1,580.4	60.9	0.39
670	1,347.9	1,581.9	71.6	0.54
770	1,346.8	1,579.2	76.1	0.67

Table 2. The curve fitting results for second-order Raman peak using the Lorentzian distribution function

Sample (°C)	2D1		2D2		I2D1/I2D2 ratio	2D2–2D1 (cm^−1)
	Position (cm^−1)	Width (cm^−1)	Position (cm^−1)	Width (cm^−1)
370	2,703.3	46.2	2,707.9	76.0	0.12	4.6
420	2,669.7	81.2	2,694.5	83.4	0.40	24.8
470	2,683.0	55.7	2,706.2	58.8	0.69	23.2
520	2,673.3	57.6	2,704.6	61.8	0.23	31.3
570	2,703.9	37.6	2,729.2	56.3	0.24	25.3
670	2,687.4	68.8	2,703.1	78.9	0.13	15.7
770	2,701.1	35.1	2,716.5	77.0	0.10	15.4

Table 3. Diameter, length and the growth rate of the CNTs synthesised using different catalyst concentration of 1.33–10.33 wt%

Sample (wt%)	Diameter (nm)	Average length (μm)	Growth rate (μm min^−1)
1.33	30.2–70.7	–	–
3.33	29.5–66.5	19.5	0.33
4.33	25.3–35.7	24.5	0.41
5.33	18.1–31.2	65.5	1.09
6.33	29.5–37.5	37.6	0.63
7.33	36.4–41.3	36.6	0.61
10.33	32.7–75.4	19.8	0.33

Figure 4. Micro-Raman spectra of the sample synthesised using different catalyst concentration of 1.33–10.33 wt%.

Table 4. The D and G peaks position and the I_D/I_G ratio of the sample synthesised using catalyst concentration of 1.33–10.33 wt%.

Sample (wt%)	D peak (cm^−1)	D peak width (cm^−1)	G peak (cm^−1)	G peak width (cm^−1)	ID/IG ratio
1.33	1,342.6	166.9	1,590.4	75.6	0.96
3.33	1,346.8	154.3	1,577.1	75.6	0.73
4.33	1,345.7	62.4	1,578.2	57.7	0.71
5.33	1,348.9	54.5	1,580.2	31.6	0.39
6.33	1,347.9	72.6	1,576.1	58.6	0.70
7.33	1,347.9	65.3	1,580.2	58.9	0.82
10.33	1,352.7	73.0	1,582.4	62.3	0.89

Table 5. The weight % of element content at different part of VACNTs

Area	Element	Wt%
Spectrum 1—Boundary line	C K	93.16
	Fe K	6.84
Spectrum 2—Point on boundary line	C K	93.74
	Fe K	6.26
Spectrum 3—Lower part of the boundary	C K	108.89
	Fe K	−8.89

Table 6. Diameter, length and the growth rate of the nanotubes synthesised by synthesis time of 5–90 min

Synthesis time (min)	Average CNTs length (μm)	Secondary growth length (μm)	Growth rate (μm min^−1)	Diameter (nm)
5	2.9	5.2	0.57	45.6–51.6
30	13.8	3.9	0.46	42.4–50.1
40	5.7	3.0	0.14	39.1–46.6
50	5.3	3.7	0.11	22.3–35.6
60	65.5	5.7	1.09	18.1–31.2
70	15.3	2.9	0.22	23.2–35.1
80	7.7	3.9	0.10	25.7–36.4
90	7.2	2.5	0.08	26.9–37.1

Figure 6. Micro-Raman spectra of the samples synthesised at various synthesis time of 5–90 min.

Table 7. The D, G and G′ peaks width and the I_D/I_G ratio of the sample synthesised by synthesis time of 5–90 min

Synthesis time	D peak (cm^−1)	D width (cm^−1)	G peak (cm^−1)	G width (cm^−1)	G′ peak (cm^−1)	G′ width (cm^−1)	ID/IG ratio
5	1,348.9	168.4	1,585.3	72.6	2,697.4	113.2	0.84
30	1,350.8	185.7	1,586.1	77.8	2,694.8	99.8	0.75
40	1,352.4	189.6	1,588.6	70.0	2,708.6	78.7	0.73
50	1,355.9	146.4	1,585.3	59.2	2,706.8	65.3	0.52
60	1,352.2	54.5	1,582.5	31.6	2,708.6	60.9	0.39
70	1,348.6	59.7	1,581.0	51.9	2,698.2	86.3	0.64
80	1,349.8	173.3	1,579.6	65.0	2,700.8	78.4	0.59
90	1,351.1	148.2	1,580.4	59.7	2,699.1	72.1	0.58

Figure 7. TGA and DTGA curves of VACNTs synthesised using optimum parameters.

Figure 8. (a) Typical J-E curves, (b) F-N plot and HR-TEM images of the VACNTs from waste chicken fats by (c) 30 and (d) 60 min.

Note: Red arrows indicate the defects in the nanotube.