Synthesis and Characterization of Graphitic Carbon Nanostructures from Cellulose Extraction of Durian Peel Waste

The synthesis of graphitic carbon nanostructures from cellulose extraction of durian peel waste has been successfully carried out in this study. This study aim to produce the graphitic carbon nanostructures to give innovative solutions to the renewable energy storage challenge. Durian peel cellulose was synthesized into graphitic carbon nanostructures through catalytic graphitization method. 4.8 grams of durian peel cellulose was hydrocharred at 200°C for 4 hours, then impregnated using Fe(NO3).9H2O and ethanol for 90 minutes. The sample was then precipitated for 12 hours and dried at 60°C. The sample was pyrolysed at 900°C for 3 hours. Characterization was carried out using TEM and XRD. Characterization TEM showed the morphological characteristics of graphitic carbon nanostructures in the form of coils in uneven amounts with the avarage diameter size is 24.9134 nm. In addition, the XRD characterization results also strengthen the characteristic phase of graphitic carbon nanostructures at 2θ 26.5° and 44.7°, although nanoparticles from Fe catalysis are visible in the sample due to the absence of reflux.


Introduction
The use of portable electronic gadgets has increased dramatically in recent decades.This is corelated to the use of rechargeable batteries as a source of energy [1,2].The lithium ion battery is the most common rechargeable battery used in portable electronic devices nowadays [3].However, as its resources are depleted, the cost of lithium raw materials is rising.As an alternative, sodium ion batteries exhibit characteristics that are similar to lithium ion batteries [2,4,5].However, sodium ion batteries are less likely to overheat than lithium ion batteries and high abundance of resources [6].
Sodium ion batteries, like lithium ion batteries, are made up of four components: a cathode, an anode, a separator, and an electrolyte [7].Essentially, careful selection of these components can boost the energy density of sodium ion batteries.However, carbon-based filler materials must also be addressed in order to improve the conductivity of sodium ion batteries.Carbon filler compounds improve cycle stability and performance in ion batteries compared to those without them [8][9][10].
Acetylene black is the most commonly used carbon filler ingredient in ion batteries.However, when compared to graphite fillers, graphite fillers outperform acetylene black [10].Graphite is classified into natural graphite and synthetic graphite.Natural graphite resources are scarce, however synthetic graphite is abundant and can be produced from biomass waste [11].Cellulose, hemicellulose, and lignin are all components of synthesis graphite made from biomass waste.Biomass utilized in the creation of synthetic graphite is often derived from bagasse, wood, grass, rice husk, banana peel, coconut shell, and other sources [12][13][14][15][16][17].
Graphitic carbon nanostructures are nanosized carbon materials with a graphite structure.Graphitic carbon nanostructures are appealing due to their high electrical conductivity and surface area, making them ideal for energy storage applications [8,16].Graphitic carbon nanostructures can be synthesized utilizing the catalytic graphitization method with biomass waste as the primary raw material.The catalytic graphitization method is an effective procedure for creating graphitic carbon nanostructures.Hydrochar, impregnation, and pyrolysis are the three steps in the catalytic graphitization process.However, before beginning the hydrochar process, cellulose must be recovered from biomass waste, which serves as the raw material for graphitic carbon nanostructures [16].
Medan City has one of the highest durian consumption rates in Indonesia [18].However, the use of durian peel waste in Medan City as a source of biomass graphitic carbon nanostructures has not been investigated.Meanwhile, durian peel waste has 31-35% cellulose, 10-11% lignin, and 15-18% hemicellulose [19].This shows that durian peel waste could be used to make graphitic carbon nanostructures.
In this study, graphitic carbon nanostructures were synthesized using durian peel waste as a raw material by a catalytic graphitization process [16].The objective of this study is to create graphitic carbon nanostructures from cellulose extract of durian peel waste and bring value to durian peel waste in Indonesia, namely in Medan City.Furthermore, the graphitic carbon nanostructures created can be used as filler materials to improve the conductivity of sodium ion batteries.As a result, it has the potential to give innovative solutions to the renewable energy storage challenge.

Materials and Methods
This section will explain about materials, methods and characterization were carried out in this study.

Methods
In this study, graphitic carbon nanostructures are synthesized in two steps using cellulose extracted from durian peel waste.The first stage involves the production of durian peel cellulose from durian peel waste using alkaline hydrolysis and bleaching techniques.The durian peel waste from Medan City was cut into small pieces, washed, and dried at 100℃.The durian peel was then processed into powder using a blender.Durian peel powder was base hydrolyzed with 4M NaOH at 80℃ for 4 hours.Following base hydrolysis, samples are dried at 60℃.Bleaching was done using 2.5% NaOCl at 70℃ for 30 minutes.After bleaching, the samples were dried at 60℃.Furthermore, durian peel cellulose samples were characterized.In the second stage, graphitic carbon nanostructures were synthesized by extracting durian peel cellulose using the catalytic graphitisation process.4.8 grams of durian peel cellulose were dissolved in 60 mL of distilled water and agitated for 4 hours with a magnetic stirrer.Next, the solution was transferred to teflon and placed in an autoclave.The autoclave was placed in a furnace set to 200℃ for 4 hours, a process known as hydrochar.The material was filtered, rinsed with distilled water, and dried at 120℃ for 4 hours.The next step was to impregnate the iron nitrate nanohydrate catalyst [Fe(NO3)3.9H2O] in ethanol solution (~6 mmol metal.g - C) and mix for 90 minutes.The product was precipitated for 12 hours and dried at 60℃.The final step is pyrolysis at 900℃ for 3 hours.Futhermore, the samples of durian peel graphitic carbon nanostructures were characterized.

Characterization
Durian peel cellulose samples were characterized using FTIR (Shimadzu-Prestige21) to identify functional groups and XRD (Phillips Analytical PW1710) to assess phase formation.While the samples of durian peel graphitic carbon nanostructures were characterized using TEM (JEM-1400 120 kV) to characterized morphological and using XRD (Phillips Analytical PW1710) to determinate phase.

Figure 1. FTIR spectrum of durian peel waste cellulose extraction.
The signal at 3408 cm -1 represents the presence of the -OH functional group in the cellulose sample [20,21].The peak at 2900 cm -1 suggests C-H stretching vibrations in the cellulose and hemicellulose structures [20,21].The peak at 1633 cm -1 corresponds to the vibration of -OH by abdorbed water in the cellulose structure [20,21].The 1427 cm -1 wave number peak is created by bending vibrations of H-C-H and O-C-H.The 1373 cm -1 and 1317 cm -1 peaks are impacted by C-OH vibration and C-H asymmetric deformation in the cellulose structure [20,21].The peak at 1239 cm -1 can be attributed to carbonyl groups C=O [22].The peak at 1161 cm -1 is corresponds to the C-O-C stretching group [20,21,23].The peak at 1060 cm -1 is indicated the stretching vibration of the CO group.
The peak at 896 cm -1 is formed by a glycosidic chain between glucose units in cellulose, but the peaks at 669 cm -1 and 613 cm -1 suggest out-of-plane bending of -OH.The FTIR results of the sample show as well as FTIR patterns similar to commercial cellulose, implying that cellulose from durian peel waste was successfully extracted through alkaline hydrolysis and bleaching processes.
Figure 2 shows the findings of phase characterization of durian peel cellulose with XRD, which is used to determine crystalline behavior.Cellulose in the molecular structure is partially amorphous and partially crystalline, therefore the cellulose chain is dominated by reciprocal H-bonds in the crystalline region, but there are no H-bonds in the amorphous section of the durian skin cellulose chain.Figure 2 shows two peaks of 16.5°, 22.5°, and 34.6° in the (1 1 0), (2 0 0), and (0 0 4) planes.These peaks correlate to the typical peaks of the cellulose structure [19,23].These results reinforce the FTIR analysis of the previous durian peel cellulose extraction, that durian peel waste has been successfully extracted into durian peel cellulose.As previously stated, cellulose satisfactorily recovered from durian peel waste is used to synthesize graphitic carbon nanostructures.Following synthesis, samples of graphitic carbon nanostructures derived from durian peel waste were characterized using TEM and XRD.catalyst nanoparticles across the surface of amorphous carbon, leaving traces of graphitic carbon nanostructures.The nanoparticles of the Fe catalyst are solid black and spherical to oval in shape [16].4 shows the analysis results of diameter size distribution from graphitic carbon nanostructures of durian peel waste representative in TEM micrograph at Figure 3 (a).Based on analysis using Image-J and Origin Software, the avarage diameter size of graphitic carbon nanostructures from durian peel waste is 24.9134 nm.This results support the morphologycal caharcteristic of graphitic carbon nanostructures of durian peel waste was shown on figure 3. Futhermore, the results also convinced that the sample was formed on nanoscale.
Figure 5 shows the XRD diffraction spectrum of the sample of graphitic carbon nanostructures made from durian peel waste.According to PDF2 number 00-075-1621, peak 2 26.5° corresponds to the graphite phase with a hexagonal structure in the main crystal plane (002) [24].In addition, based on PDF2 number 03-065-6329, there are two more peaks, namely 2 44.7° and 60°.These are carbon phases according to the main crystal plane (002) with a cubic carbon structure [24].PDF2 numbers 350772 and 060696 show the presence of Fe and Fe3C phases at 2 44.7 °.This is further supported by the TEM data (Figure 3), which show the presence of Fe in the durian skin graphitic carbon nanostructures sample.The existence of Fe in the sample is most likely due to the absence of reflux.The reflux procedure can remove Fe catalyst nanoparticles [16].

Conclusion
In this study, cellulose from durian peel waste was successfully recovered, as evidenced by FTIR data showing the existence of -OH, CO, C-H, C-OH, C-O-C, and C=O functional groups.The XRD analysis of durian peel waste cellulose samples confirmed their cellulose content, with peaks indicating cellulose structures at 2θ = 16.5°,22.5°, and 34.6°.Similarly, graphitic carbon nanostructures from cellulose extraction of durian peel waste were successfully synthesized in this research.This is showed by the TEM data, which indicate the morphological properties of graphitic carbon nanostructures in the shape of coils in uneven numbers with the avarage diameter size is 24.9134 nm.XRD analysis confirms that graphitic carbon nanostructures exhibit phase features at 2θ 26.5° and 44.7°.However, the nanoparticles produced by Fe catalysis are black in colour and spherical to oval in shape.

Figure 3 .
Figure 3. (a) TEM micrograph of graphitic carbon nanostructures of durian peel waste and (b) the mapping of distribution of FeK element (orange) and C K element (purple) in the graphitic carbon nanostructures from durian peel waste.

Figure 3 (
Figure 3 (a) shows TEM characterization of graphitic carbon nanostructures from durian peel waste and Figure 3 (b) shows the mapping of distribution of FeK element (orange) and C K element (purple) in the graphitic carbon nanostructures from durian peel waste.Coil-shaped morphology of graphitic carbon nanostructures in varying proportions.The shape generated is the result of the movement of Fe

Figure 4 .
Figure 4. Diameter size distribution from graphitic carbon nanostructures of durian peel waste representative in TEM micrograph.

Figure 5 .
Figure 5. XRD diffraction spectra of graphitic carbon nanostructures of durian peel waste.