Description:Form 2

THE PATENT ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

“A PROCESS OF RAPID, INNOVATIVE AND HIGH YIELD GRAPHENE QUANTUM DOTS SYNTHESIS BY MICROWAVE PYROLYSIS”

in the name of KOTHARI SUGARS AND CHEMICALS LTD an Indian National having address at KOTHARI BUILDINGS, 115 MAHATMA GANDHI ROAD, NUNGAMBAKKAM, CHENNAI, CHENNAI – 600034, TAMIL NADU, INDIA.

The following specification particularly describes the invention and the manner in which it is to be performed.

SOURCE AND GEOGRAPHICAL ORIGIN OF THE BIOLOGICAL MATERIAL:

SL.
NO COMMON NAME SCIENTIFIC NAME PART OF BIOLOGICAL SOURCES SOURCE OF ACCESS DETAILS OF GEOGRAPHICAL LOCATION
1. Sugarcane Saccharum officinarum Culm (Bagasse or pith) Trader (i) Name of the Trader:
Kothari sugars and chemicals Ltd

(ii) Contact details: Sathamangalam village,
Vettriyur post, Ariyalur district – 621707.
2. Lemon Citrus limon Fruit Trader (i) Name of the trader:
Sigma Aldrich.

(ii) Contact details:
No.12,
Bommasandra Jigani
Link Rd, Bommasandra
Industrial Area,
Bengaluru,
Bommasandra,
Karnataka-560099.

FIELD OF THE INVENTION:

The present invention generally relates to a process for synthesizing graphene quantum dots. More particularly, the present invention relates to a process for synthesizing graphene quantum dots from sugarcane bagasse or sugarcane bagasse pith and product thereof.

BACKGROUND OF THE INVENTION:

The emergence of a new biomass-based product is a uniting goal for the world in order to address conflicts caused by environmental pollution and the energy concerns (Chai et al., 2019). Graphene Quantum Dots (GQDs) are a new class of carbon-based nanomaterial, developed in 2008, typically having a diameter of less than 20 nm.

Various methods including top-down and bottom-up approaches are used to synthesize Graphene Quantum Dots. Top-down methods include acidic oxidation, hydrothermal method, electrochemical oxidation and exfoliation were used to synthesize Graphene Quantum Dots from larger sp2 or sp3 carbon allotropes of graphene, carbon fibers, graphene oxide or carbon black. The bottom-up approach uses small molecules as the basic components to synthesize Graphene Quantum Dots. This method involves the controlled synthesis of carbon sp2 structures from organic polymers.

Top-down and bottom-up traditional methods exhibit disadvantages.The top-down approach is primarily reliant on costly non-renewable raw materials such as graphene oxide, carbon nanotubes (CNTs), graphene and other precursors based on graphene. Moreover, hazardous chemicals and strong acidic treatments are required in the synthesis of these compounds from bulk graphite. Also, significant drawbacks of the top-down method include low yields, irregular sizes and dissimilar morphologies. The bottom-up approach indicates the organic molecule’s sequential reaction mechanism to be a difficult process under harsh conditions.

There are reports available in the state of the art relating to methods for synthesizing graphene quantum dots.

US9725324B2 discloses a graphene quantum dots synthesis method, comprising:fixing a graphene aqueous solution on a spin coater to spin the graphene aqueous solution, and the graphene aqueous solution includes deionized water and multiple graphene sheets; irradiating a pulsed laser outputted from a laser source to focus on the spinning of the graphene aqueous solution;exfoliating the multiple graphene sheets of the graphene aqueous solution; andforming multiple quantum dots with nano-size in the graphene aqueous solution.

US20210316995A1 discloses a method of preparing graphene quantum dots, comprising:a process of introducing a carbon-based layered structure into a reactor containing a solvent;a process of forming an intercalation composite by inserting an intercalant between layers of the carbon-based layered structure;a process of placing and heat-treating the intercalation composite on a substrate to weaken the interlayer attractive force of the intercalation composite; and a process of exfoliating the intercalation composite by applying a voltage to the substrate to obtain graphene quantum dots.

US9272911B2 discloses a method of producing a plurality of graphene particulates comprising: providing a source of graphite and determining the crystallographic orientation of said source of graphite; using the determined crystallographic orientation of said source of graphite to determine a cutting angle for said source of graphite; cutting a plurality of graphite blocks from said source of graphite utilizing a cutting mechanism, said source of graphite being oriented relative to said cutting mechanism such that said cutting mechanism cuts said source of graphite at said cutting angle, wherein said graphite blocks have at least one dimension of less than 100 nm; and exposing said plurality of graphite blocks to an acid and causing said graphite blocks to exfoliate into a plurality of substantially uniform, electrically semiconductive graphene particulates having an armchair edge crystallographic orientation and a band gap, said cutting angle being set so as to provide said graphene particulates having said armchair edge crystallographic orientation upon exfoliation of said graphite blocks.

Though, conventional methods for synthesizing graphene quantum dots exhibits advantages in the prior arts they do have disadvantages such as use of expensive and non-renewable raw materials, involving complex operation processes, use of hazardous chemicals and harsh acidic processes raises issues with the environment and public health, the process utilizes high-pressure, high-temperature equipment, which adds to their complexity and energy requirements while frequently producing low yields and limiting their capacity to scale.

Thus, there exists a need in the state of art for developing an alternative method for synthesizing graphene quantum dots.

Hence an attempt has been made to develop a simple, cost effective, sustainable and environmental friendly method for synthesizing graphene quantum dots overcoming the above said drawbacks.

References:

Abbas, A., Mariana, L.T., Phan, A.N., 2018. Biomass-waste derived graphene quantum dots and their applications. Carbon N Y 140, 77–99. https://doi.org/10.1016/j.carbon.2018.08.016

Agarwal, N.K., Kumar, M., Pattnaik, F., Kumari, P., Vijay, V.K., Kumar, V., 2023. Exploring the Valorization Potential of Sugarcane Bagasse Pith: a Review. Bioenergy Res 16, 1280–1295. https://doi.org/10.1007/s12155-023-10632-4

Alves, M., Ponce, G.H.S.F., Silva, M.A., Ensinas, A. V., 2015. Surplus electricity production in sugarcane mills using residual bagasse and straw as fuel. Energy 91, 751–757. https://doi.org/10.1016/j.energy.2015.08.101

Arshad, M., Ahmed, S., 2016. Cogeneration through bagasse: A renewable strategy to meet the future energy needs. Renewable and Sustainable Energy Reviews 54, 732–737. https://doi.org/10.1016/j.rser.2015.10.145

Ashraf, H., Solla, P., Sechi, L.A., 2022. Current Advancement of Immunomodulatory Drugs as Potential Pharmacotherapies for Autoimmunity Based Neurological Diseases. Pharmaceuticals 15, 1077. https://doi.org/10.3390/ph15091077

Batista, G., Souza, R.B.A., Pratto, B., dos Santos-Rocha, M.S.R., Cruz, A.J.G., 2019. Effect of severity factor on the hydrothermal pretreatment of sugarcane straw. BioresourTechnol 275, 321–327. https://doi.org/10.1016/j.biortech.2018.12.073

Chai, X., He, H., Fan, H., Kang, X., Song, X., 2019. A hydrothermal-carbonization process for simultaneously production of sugars, graphene quantum dots, and porous carbon from sugarcane bagasse. BioresourTechnol 282, 142–147. https://doi.org/10.1016/j.biortech.2019.02.126

Chen, W., Li, D., Tian, L., Xiang, W., Wang, T., Hu, W., Hu, Y., Chen, S., Chen, J., Dai, Z., 2018. Synthesis of graphene quantum dots from natural polymer starch for cell imaging. Green Chemistry 20, 4438–4442. https://doi.org/10.1039/C8GC02106F

Devi, M.S., Thangadurai, T.D., Manjubaashini, N., Nataraj, D., 2023. Walnut shell biomass waste derived excitation-dependent CQDs for toxic insecticide sensing and protein denaturation inhibition – An ecofriendly and sustainable approach. DiamRelat Mater 136, 110021. https://doi.org/10.1016/j.diamond.2023.110021

Elumalai, D., Hemavathi, M., Mary, D., Remya, R.R., Naima, H., Stalin, A., Keerthiga, R., Suman, T.Y., 2023. Ecofriendly biofunctionalized gold nanoparticles using naturally available extract and evaluation of antioxidant, anticancer, antimicrobial and their toxicity in brine shrimp. Biocatal Agric Biotechnol 54, 102906. https://doi.org/10.1016/j.bcab.2023.102906

Gao, X., Zhou, X., Ma, Y., Qian, T., Wang, C., Chu, F., 2019. Facile and cost-effective preparation of carbon quantum dots for Fe3+ ion and ascorbic acid detection in living cells based on the “on-off-on” fluorescence principle. Appl Surf Sci 469, 911–916. https://doi.org/10.1016/j.apsusc.2018.11.095

Gudimella, K. kanthi, Gedda, G., Kumar, P.S., Babu, B.K., Yamajala, B., Rao, B.V., Singh, P.P., Kumar, D., Sharma, A., 2022. Novel synthesis of fluorescent carbon dots from bio-based Carica Papaya Leaves: Optical and structural properties with antioxidant and anti-inflammatory activities. Environ Res 204, 111854. https://doi.org/10.1016/j.envres.2021.111854
Hao, Y.-N., Guo, H.-L., Tian, L., Kang, X., 2015. Enhanced photoluminescence of pyrrolic-nitrogen enriched graphene quantum dots. RSC Adv 5, 43750–43755. https://doi.org/10.1039/C5RA07745A

Iravani, S., Varma, R.S., 2020. Green synthesis, biomedical and biotechnological applications of carbon and graphene quantum dots. A review. Environ Chem Lett 18, 703–727. https://doi.org/10.1007/s10311-020-00984-0

Kalluri, A., Debnath, D., Dharmadhikari, B., Patra, P., 2018. Graphene Quantum Dots: Synthesis and Applications. pp. 335–354. https://doi.org/10.1016/bs.mie.2018.07.002

M, A., I, M.A., Ramalingam, K., S, R., 2023. Evaluation of the Anti-inflammatory, Antimicrobial, Antioxidant, and Cytotoxic Effects of Chitosan Thiocolchicoside-Lauric Acid Nanogel. Cureus. https://doi.org/10.7759/cureus.46003

Murugesan, B., Sonamuthu, J., Pandiyan, N., Pandi, B., Samayanan, S., Mahalingam, S., 2018. Photoluminescent reduced graphene oxide quantum dots from latex of Calotropis gigantea for metal sensing, radical scavenging, cytotoxicity, and bioimaging in Artemia salina: A greener route. J PhotochemPhotobiol B 178, 371–379. https://doi.org/10.1016/j.jphotobiol.2017.11.031

Nirala, N.R., Khandelwal, G., Kumar, B., Vinita, Prakash, R., Kumar, V., 2017. One step electro-oxidative preparation of graphene quantum dots from wood charcoal as a peroxidase mimetic. Talanta 173, 36–43. https://doi.org/10.1016/j.talanta.2017.05.061

Pan, D., Guo, L., Zhang, J., Xi, C., Xue, Q., Huang, H., Li, J., Zhang, Z., Yu, W., Chen, Z., Li, Z., Wu, M., 2012. Cutting sp2 clusters in graphene sheets into colloidal graphene quantum dots with strong green fluorescence. J Mater Chem 22, 3314. https://doi.org/10.1039/c2jm16005f

Peng, J., Gao, W., Gupta, B.K., Liu, Z., Romero-Aburto, R., Ge, L., Song, L., Alemany, L.B., Zhan, X., Gao, G., Vithayathil, S.A., Kaipparettu, B.A., Marti, A.A., Hayashi, T., Zhu, J.-J., Ajayan, P.M., 2012. Graphene Quantum Dots Derived from Carbon Fibers. Nano Lett 12, 844–849. https://doi.org/10.1021/nl2038979

Ravichandran, P.K., Munusamy, C., 2022. Optimization of reduced Graphene oxide synthesis using central composite design analysis—A waste to value approach. Environmental Science and Pollution Research 30, 28259–28273. https://doi.org/10.1007/s11356-022-24018-0

Shinde, D.B., Pillai, V.K., 2012. Electrochemical Preparation of Luminescent Graphene Quantum Dots from Multiwalled Carbon Nanotubes. Chemistry – A European Journal 18, 12522–12528. https://doi.org/10.1002/chem.201201043

Singh, S., Prasad, A.S., Rajeshkumar, S., 2023. Cytotoxicity, antimicrobial, anti-inflammatory and antioxidant activity of camellia sinensis and citrus mediated copper oxide nanoparticle—An in vitro study. J Int Soc Prev Community Dent 13, 450–457. https://doi.org/10.4103/jispcd.JISPCD_76_23

Sohal, N., Singla, S., Malode, S.J., Basu, S., Maity, B., Shetti, N.P., 2023. Bioresource-Based Graphene Quantum Dots and Their Applications: A Review. ACS Appl Nano Mater 6, 10925–10943. https://doi.org/10.1021/acsanm.3c02185

Wang, X., Sun, G., Li, N., Chen, P., 2016. Quantum dots derived from two-dimensional materials and their applications for catalysis and energy. Chem Soc Rev 45, 2239–2262. https://doi.org/10.1039/C5CS00811E

Ye, R., Xiang, C., Lin, J., Peng, Z., Huang, K., Yan, Z., Cook, N.P., Samuel, E.L.G., Hwang, C.-C., Ruan, G., Ceriotti, G., Raji, A.-R.O., Martí, A.A., Tour, J.M., 2013. Coal as an abundant source of graphene quantum dots. Nat Commun 4, 2943. https://doi.org/10.1038/ncomms3943

Zeng, Z., Chen, S., Tan, T.T.Y., Xiao, F.-X., 2018. Graphene quantum dots (GQDs) and its derivatives for multifarious photocatalysis and photoelectrocatalysis. Catal Today 315, 171–183. https://doi.org/10.1016/j.cattod.2018.01.005

Zhao, L., Wang, Y., Li, Y., 2019. Antioxidant Activity of Graphene Quantum Dots Prepared in Different Electrolyte Environments. Nanomaterials 9, 1708. https://doi.org/10.3390/nano9121708.

OBJECT OF THE INVENTION:

The main object of the present invention is to develop a process of synthesis of graphene quantum dots.

Another object of the present invention is to develop a process of synthesis of graphene quantum dots from sugarcane bagasse or sugarcane bagasse pith.

Yet another object of the present invention is to synthesize graphene quantum dots employing carbonized sugarcane bagasse or carbonized sugarcane bagasse pith, citric acid and deionized water.
Further object of the present invention is to utilize the synthesized graphene quantum dots in various biomedical applications.

BRIEF DESCRIPTION OF DRAWINGS:

Figure 1 depicts a pictorial representation for process of synthesis of graphene quantum dots of the present invention.

Figure 2 depicts UV-Visible spectrum and PL spectra of GQDs-SB and GQDs-SBP under different excitation wavelength.
(a) UV-Visible spectrum of GQDs-SB and GQDs-SBP.
(b) PL spectra of GQDs-SB.
(c) PL spectra of GQDs-SBP.

Figure 3 depicts FT-IR Analysis of GQDs-SB and GQDs-SBP of the present invention.

Figure 4 depicts High resolution transmission electron microscope HR-TEM analysis of graphene quantum dots of the present invention.
(a-c) GQDs-SB and
(d-f) GQDs-SBP.

SUMMARY OF THE INVENTION:

The present invention discloses a process of synthesis of graphene quantum dots from sugarcane bagasse or sugarcane bagasse pith comprises of following steps;
a. carbonizing dried and powdered sugarcane bagasse or sugarcane bagasse pith to form carbonized substance;
b. dissolving citric acid in deionized water followed by adding the carbonized substance to form a solution;
c. sonicating the solution to form a mixture;
d. subjecting the mixture to microwave pyrolysis followed by filtration and dialysis to obtain graphene quantum dots.
The present invention also a graphene quantum dots prepared by the process as described above.

DETAILED DESCRIPTION OF THE INVENTION:

The present invention discloses a process of synthesis of graphene quantum dots from sugarcane bagasse or sugarcane bagasse pith and product thereof.

The present invention uses sugarcane bagasse and sugarcane bagasse pith as the starting materials which are easily available and renewable resources. The present invention offers a transformation from waste to value-added products.

Sugarcane bagasse and sugarcane bagasse pith were collected from the industry, Kothari sugars and Chemicals Ltd, Sathamangalam Village, Vettriyur Post, Ariyalur District, 621707, Tamil Nadu. Citric Acid was purchased at Sigma Aldrich.

The present invention comprises of following steps: Initially, sugarcane bagasse is collected, rinsed using distilled water for multiple times and dried in a hot air oven at 80oC, and then processed into a fine powder. Burning the powdered bagasse in a muffle furnace at 600oC for 1h to obtain carbonized bagasse. Then, dissolving the citric acid in deionized water followed by adding the carbonized bagasse to form a solution. Sonicating the solution in an ultrasonic bath for 30 min to form a mixture. Then, subjecting the mixture to microwave pyrolysis at 750 watts for 30 minutes. Finally, filtering the solution via Whatmann filter paper No.1 and dialyzing the filtered solution for one day to obtain graphene quantum dots (Figure 1).

The same procedure has to be followed for sugarcane bagasse pith to synthesize graphene quantum dots. Sugarcane bagasse pith is collected, rinsed using distilled water for multiple times and dried in a hot air oven at 80oC, and then processed into a fine powder. Burning the powdered bagasse pith in a muffle furnace at 600oC for 1 h to obtain carbonized pith. Then, dissolving the citric acid in deionized water followed by adding the carbonized pith to form a solution. Sonicating the solution in an ultrasonic bath for 30 min to form a mixture. Then, subjecting the mixture to microwave pyrolysis at 750 watts for 30 minutes. Finally, filtering the solution via Whatman filter paper No.1 and dialyzing the filtered solution for one day to obtain graphene quantum dots (Figure 1).

Composition of graphene quantum dots of the present invention:

S. No. Ingredients Quantity
1. Carbonized substance 1 g
2. Citric acid 1gm
3. Deionized water 50mL

The prepared graphene quantum dots of the present invention were then subjected to characterization by UV-visible spectrophotometer analysis, photoluminescence spectra analysis, FTIR Analysis and high-resolution transmission electron microscope (HRTEM) analysis.

UV-Visible Spectroscopy:

The electronic transition of GQDs-SB and GQDs-SBP were performed on HITACHI U-2900 Spectrophotometer.

The UV-Visible spectrum of the obtained GQDs-SB and GQDs-SBP is illustrated in Figure 2(a). The absorption peak at 248 nm for GQDs-SB and 243 nm for GQDs-SBP corresponds to p-p* transition of the aromatic sp2 domains and shoulder peak at 370 nm for both GQDs-SB and GQDs-SBP corresponds to n-p* transition which is a characteristic peak for GQDs (Iravani and Varma, 2020).

Photoluminescence spectra:

The photoluminescence characteristics of the synthesized GQDs-SB and GQDs-SBP were examined using the fluorescent spectrophotometer. The specific photoluminescence setup a Fluorolog HORIBA was used to analyze the photoluminescence properties of GQDs-SB and GQDs-SBP in an aqueous solution. By exciting the GQDs-SB and GQDs-SBP with a particular wavelength and monitoring the fluorescence that was released, the photoluminescence spectra were recorded.

As shown in Figure 2(b) and 2(c), the Photoluminescence spectra of GQDs-SB and GQDs-SBP at different excitation wavelength was analyzed. Both GQDs-SB and GQDs-SBP show the excitation independent photoluminescence behavior and had fluorescence peaks at roughly 450 nm and the emission intensity improved as the excitation wavelength increased from 250 nm to 340 nm. The highest emission intensity was observed at the excitation wavelength of 340 nm for both GQDs-SB and GQDs-SBP (Nirala et al., 2017).

FTIR analysis:

The surface functional groups of GQDs-SB and GQDs-SBP were determined using the FTIR technique. The size, shape and structural characteristics of the synthesized GQDs-SB and GQDs-SBP were studied using a JEOL Japan, JEM-2100 Plus. The copper grid was coated with a drop of GQDs-SB and GQDs-SBP solution, and it was then dried over a hot plate and analyzed.

The absorbance peak of GQDs-SB and GQDs-SBP varied between 500 and 4000 cm-1 based on FTIR measurements. The existence of the hydroxyl (O-H) functional groups is shown by broad absorption band at 3307 cm-1 for GQDs-SBP as well as GQDs-SB and the existence of the C=O functional group is shown by an intense band at 1640 cm-1 for both GQDs-SB and GQDs-SBP (Kalluri et al., 2018). FTIR analysis (JASCO FTIR-4700, Japan) confirms the existence of functional groups in GQDs-SB and GQDs-SBP in the wavelength region 4000–500 cm-1 (Figure 3).

HR-TEM Analysis:

The size and structures of the developed GQDs-SB and GQDs-SBP were examined and characterized using HR-TEM analysis as shown in Figure 4.

The average size of GQDs-SB was approximately 7 nm and GQDs-SBP was 5 nm, respectively. HR-TEM images highlighted the precise crystalline structures of the synthesized GQDs-SB and GQDs-SBP (Figure 4) with a distinct lattice spacing of about 0.24 nm for both GQDs-SB and GQDs-SBP that was in line with the sp2 graphitic carbon diffraction planes (1120), suggesting that the crystalline state of GQDs-SB and GQDs-SBP was identical to that of graphene. Both the dimension and the lattice spacing of the GQDs-SB and GQDs-SBP are in good alignment with the HR-TEM result that was obtained through different methods (Hao et al., 2015).
In the present study, an innovative approach to prepare graphene quantum dots using agricultural waste sugarcane bagasse and sugarcane bagasse pith was reported. The optical property of the prepared GQDs-SB and GQDs-SBP were analyzed by UV-Visible and Photoluminescence spectroscopy. The size and crystalline state of GQDs-SB and GQDs-SBP were determined by HR-TEM analysis. Thus, the present method provides a sustainable way to develop value-added graphene quantum dots using agricultural waste, sugarcane bagasse or sugarcane bagasse pith as a raw material.

Advantages:

• The process of the present invention is economical, environmentally friendly, sustainable, and solving pollution issues globally.
• The process of the present invention is quicker and simpler, which reduces complexity and energy usage.
• The process of the present invention is sustainably transforming agricultural waste sugarcane bagasse or sugarcane bagasse pith into value-added graphene quantum dots.
• Sugarcane bagasse or sugarcane bagasse pith, an often-discarded agricultural residue is repurposed as a potential source of carbon for the synthesis of graphene quantum dots thereby minimizing waste and maximizing resource utilization.

Thus, from the above it is concluded that the prepared graphene quantum dots by the process of the present invention be a suitable candidate for use in biomedical applications as the process is simple and cost-effective than the existing ones.

In one of the preferred embodiments, the present invention shall disclose a process of synthesis of graphene quantum dots from sugarcane bagasse or sugarcane bagasse pith comprises of following steps;

a. carbonizing dried and powdered sugarcane bagasse or sugarcane bagasse pith to form carbonized substance;
b. dissolving citric acid in deionized water followed by adding the carbonized substance to form a solution;
c. sonicating the solution to form a mixture;
d. subjecting the mixture to microwave pyrolysis followed by filtration and dialysis to obtain graphene quantum dots.

In another preferred embodiment, the present invention shall disclose a graphene quantum dots prepared by the process as described above.

In yet another preferred embodiment, the present invention shall disclose a process of synthesis of graphene quantum dots from sugarcane bagasse or sugarcane bagasse pith comprises of following steps;

a. carbonizing dried and powdered sugarcane bagasse or sugarcane bagasse pith in muffle furnace at 600oC for 1 h to form carbonized substance;
b. dissolving 1gm of citric acid in 50mL of deionized water followed by adding 1 g of the carbonized substance to form a solution;
c. sonicating the solution in an ultrasonic bath for 30 min to form a mixture;
d. subjecting the mixture to microwave pyrolysis at 750 watts for 30minutes followed by filtration and dialysis for 1 day to obtain graphene quantum dots.

In further preferred embodiment, the present invention shall disclose a graphene quantum dots prepared by the process as described above.

Working example 1:

Process of synthesis of graphene quantum dots from sugarcane bagasse.

The dried and powdered sugarcane bagasse was carbonized in muffle furnace at 600oC for 1 h to form carbonized bagasse.1gm of citric acid was dissolved in 50mL of deionized water further 1 g of the carbonized bagasse was added to form a solution. The solution was sonicated in an ultrasonic bath for 30 min to form a mixture. The mixture was subjected to microwave pyrolysis at 750 watts for 30 minutes further filtered and dialyzed for 1 day to obtain graphene quantum dots.

Working example 2:

Process of synthesis of graphene quantum dots from sugarcane bagasse pith.

The dried and powdered sugarcane bagasse pith was carbonized in muffle furnace at 600oC for 1 h to form carbonized pith.1gm of citric acid was dissolved in 50mL of deionized water further 1 g of the carbonized pith was added to form a solution. The solution was sonicated in an ultrasonic bath for 30 min to form a mixture. The mixture was subjected to microwave pyrolysis at 750 watts for 30 minutes further filtered and dialyzed for 1 day to obtain graphene quantum dots.
Although the invention has now been described in terms of certain preferred embodiments and exemplified with respect thereto, one skilled in art can readily appreciate that various modifications, changes, omissions and substitutions may be made without departing from the scope of the following claims.
, Claims:WE CLAIM:

1. A process of synthesis of graphene quantum dots from sugarcane bagasse or sugarcane bagasse pith comprises of following steps;

a. carbonizing dried and powdered sugarcane bagasse or sugarcane bagasse pith to form carbonized substance;

b. dissolving citric acid in deionized water followed by adding the said carbonized substance to form a solution;

c. sonicating the said solution to form a mixture;

d. subjecting the said mixture to microwave pyrolysis followed by filtration and dialysis to obtain graphene quantum dots.

2. A graphene quantum dots prepared by the process as claimed in claim 1.

3. A process of synthesis of graphene quantum dots from sugarcane bagasse or sugarcane bagasse pith comprises of following steps;

a. carbonizing dried and powdered sugarcane bagasse or sugarcane bagasse pith in muffle furnace at 600oC for 1 h to form carbonized substance;

b. dissolving 1gm of citric acid in 50mL of deionized water followed by adding 1 g of the said carbonized substance to form a solution;
c. sonicating the said solution in an ultrasonic bath for 30 min to form a mixture;

d. subjecting the said mixture to microwave pyrolysis at 750 watts for 30 minutes followed by filtration and dialysis for 1 day to obtain graphene quantum dots.

4. A graphene quantum dots prepared by the process as claimed in claim 3.

Dated this 02nd day of APR 2024

For KOTHARI SUGARS AND CHEMICALS LTD
By its Patent Agent

Dr.B.Deepa
IN/PA 1477