Production method of low dimensional nano-material

Abstract

A production method of low dimensional nano-material comprises steps of: introducing a layered material; adding an intercalating agent into the layered material; and exfoliating the layered material by ball-milling to form the low dimensional material. Mechanochemical approaches for low dimensional nano-material like graphene quantum dots synthesis offer a promise of new reaction pathways, and greener and more efficient syntheses, making them potential approaches for low cost production.

Claims

1. A production method of low dimensional nano-material comprising steps of: introducing a layered material; adding a intercalating agent into the layered material; and exfoliating the layered material by ball-milling to form the low dimensional material; wherein: a rotational speed of ball-milling is at a range of 500 rpm to 1250 rpm; an energy of ball-milling is at a range of 15 GJ to 585.94 GJ, and a process time of ball-milling is at a range of 2 hours to 5 hours.

2. The production method of low dimensional nano-material as claimed in claim 1, wherein: the layered material contains graphite, graphene or molybdenum disulfide.

3. The production method of low dimensional nano-material as claimed in claim 1, wherein: the intercalating agent comprises potassium carbonate, lithium carbonate, potassium hydroxide, potassium phosphate, sodium carbonate, sodium hydroxide, lithium hydrate, sodium bicarbonate, potassium nitrate, potassium bicarbonate or potassium sulphate.

4. The production method of low dimensional nano-material as claimed in claim 2, wherein: the intercalating agent comprises potassium carbonate, lithium carbonate, potassium hydroxide, potassium phosphate, sodium carbonate, sodium hydroxide, lithium hydrate, sodium bicarbonate, potassium nitrate, potassium bicarbonate or potassium sulphate.

5. The production method of low dimensional nano-material as claimed in claim 1, wherein: a yield of the low dimensional nano-material is at a range of 0.88% to 100%; and a quantum luminous efficiency of the low dimensional nano-material is at a range of 1.06% to 7.4%.

6. The production method of low dimensional nano-material as claimed in claim 2, wherein: a yield of the low dimensional nano-material is at a range of 0.88% to 100%; and a quantum luminous efficiency of the low dimensional nano-material is at a range of 1.06% to 7.4%.

7. The production method of low dimensional nano-material as claimed in claim 3, wherein: a yield of the low dimensional nano-material is at a range of 0.88% to 100%; and a quantum luminous efficiency of the low dimensional nano-material is at a range of 1.06% to 7.4%.

8. The production method of low dimensional nano-material as claimed in claim 4, wherein: a yield of the low dimensional nano-material is at a range of 0.88% to 100%; and a quantum luminous efficiency of the low dimensional nano-material is at a range of 1.06% to 7.4%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The steps and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings.

(2) FIG. 1 is a flow chart of production method of a low dimensional nano-material in accordance with the present invention.

(3) FIG. 2 is an illustration of layered material being exfoliated into the low dimensional nano-material in accordance with the present invention.

(4) FIG. 3a3f is a series of TEM figures of the low dimensional nano-materials in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. It is not intended to limit the method by the exemplary embodiments described herein. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to attain a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. As used in the description herein and throughout the claims that follow, the meaning of a, an, and the may include reference to the plural unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the terms comprise or comprising, include or including, have or having, contain or containing and the like are to be understood to be open-ended, i.e., to mean including but not limited to. As used in the description herein and throughout the claims that follow, the meaning of low-dimensional will be understood as the material is in a form of particle or dot like with zero-dimension. As used in the description herein and throughout the claims that follow, the meaning of high like high production rate or high yield will be understood as not particularly to only 80 to 100%, but also referred to a relatively high quantity compared to conventional methods under similar conditions or with utilizing same materials.

(6) With reference to FIG. 1 to FIG. 2, a production method of low dimensional nano-material comprises:

(7) Step 1: introducing a layered material 10;

(8) Step 2: adding an intercalating agent 20 into the layered material 10; and

(9) Step 3: exfoliating the layered material 10 into a low dimensional nano-material by ball-milling the layered material 10 and the intercalating agent 20.

(10) The aforementioned layered material 10 has multiple layers and may be but not limited to graphite, graphene or molybdenum disulfide (MoS.sub.2). The said intercalating agent 20 is able to reduce or eliminate an attraction or a binding force like Van Der Waals Force between layers of the layered material 10.

(11) The intercalating agent 20 is preferred to be a powdered compound containing alkali metals, more preferred to be potassium carbonate (K.sub.2CO.sub.3), lithium carbonate (Li.sub.2CO.sub.3), potassium hydroxide (KOH), potassium phosphate (K.sub.3PO.sub.4), sodium carbonate (Na.sub.2CO.sub.3), sodium hydroxide (NaOH), lithium hydrate (LiOH), sodium bicarbonate (NaHCO.sub.3), potassium nitrate (KNO.sub.3), potassium bicarbonate (KHCO.sub.3) or potassium sulphate (K.sub.2SO.sub.4). The intercalating agent 20 containing alkali metals is able to produce cationic ions with a larger ionic diameter in the ball-milling step. When the cationic ions with a larger size intercalated into the layered material 10, spaces between layers of the layered material 10 will become larger or wider which may effectively decrease the attraction or the bonding force within those layers. Hence, the layered material 10 will be exfoliated more easily and efficiently.

(12) The above described low dimensional nano-material is referred to as a zero-dimensional material including quantum dots (QDs), graphene quantum dots (GQDs), carbon quantum dots (CQDs) or molybdenum disulfide quantum dots (MoS.sub.2QDs).

(13) With reference to chart 1 and chart 2 below, the present invention provides a first embodiment with several examples as follows. The layered material is graphite in the first embodiment. By using different intercalating agents and different rotational speed, process time and energy in the ball-milling process, the present invention is able to provide high quality GQDs with high quantum luminous efficiency and yields. The emitting wavelength of GQDs is at a range of 439 nm to 465 nm in the first embodiment of the present invention.

(14) TABLE-US-00001 CHART 1 Intercalating Process Ball Inter- agent: Rotational time milling calating Graphite speed of ball energy agent Solvent (g:g) (rpm) milling (hr) (GJ) K.sub.2CO.sub.3 Not exist 2:1 1250 5 585.94 Li.sub.2CO.sub.3 Not exist 2:1 1250 5 585.94 KOH Not exist 2:1 600 4 51.84 K.sub.3PO.sub.4 Not exist 2:1 1250 4 468.75 Na.sub.2CO.sub.3 Not exist 2:1 500 4 30 NaOH Not exist 2:1 500 4 30 LiOH Not exist 2:1 750 2 50.63 NaHCO.sub.3 Not exist 2:1 1000 4 240 KNO.sub.3 Not exist 2:1 750 2 50.63 KHCO.sub.3 Not exist 2:1 750 2 50.63 K.sub.2SO.sub.4 Not exist 2:1 750 2 50.63

(15) TABLE-US-00002 CHART 2 Quantum luminous Emitting Intercalating Yields efficiency wavelength agent of GQDs (%) (%) (nm) K.sub.2CO.sub.3 100 2.29 452 Li.sub.2CO.sub.3 51.15 2.16 453 KOH 6.64 2.18 440 K.sub.3PO.sub.4 6.37 1.30 441 Na.sub.2CO.sub.3 5.85 1.24 442 NaOH 5.60 1.36 440 LiOH 4.15 1.10 442 NaHCO.sub.3 2.80 2.23 438 KNO.sub.3 2.79 1.06 439 KHCO.sub.3 1.82 1.86 439 K.sub.2SO.sub.4 0.88 4.46 465

(16) With reference to chart 3 and chart 4 below, the present invention provides a second embodiment with several examples as follows. The layered material is molybdenum disulfide (MoS.sub.2) in the second embodiment. By using different intercalating agents and different rotational speed, process time and energy in the ball-milling process, the present invention is able to provide high quality MoS.sub.2QDs with high quantum luminous efficiency and yields. The emitting wavelength of MoS.sub.2QDs is at a range of 375 nm to 425 nm in the second embodiment of the present invention.

(17) TABLE-US-00003 CHART 3 Process Ball Inter- Intercalating Rotational time milling calating agent:MoS.sub.2 speed of ball energy agent Solvent (g:g) (rpm) milling (hr) (GJ) K.sub.2CO.sub.3 Not exist 2:1 1250 4 468.75 Li.sub.2CO.sub.3 Not exist 2:1 1250 4 468.75 KOH Not exist 2:1 1250 4 468.75 K.sub.3PO.sub.4 Not exist 2:1 1250 4 468.75 Na.sub.2CO.sub.3 Not exist 2:1 1250 4 468.75 NaOH Not exist 2:1 1250 4 468.75 NaHCO.sub.3 Not exist 2:1 1250 4 468.75 KHCO.sub.3 Not exist 2:1 1250 4 468.75

(18) TABLE-US-00004 CHART 4 Quantum luminous Emitting Intercalating Yields efficiency wavelength agent of GQDs (%) (%) (nm) K.sub.2CO.sub.3 24.02 7.4 395 Li.sub.2CO.sub.3 26.72 6.08 430 KOH 14.1 7.04 420 K.sub.3PO.sub.4 4.3 6.21 425 Na.sub.2CO.sub.3 35.96 7.32 420 NaOH 43.06 7.26 415 NaHCO.sub.3 4.02 6.25 395 KHCO.sub.3 2.04 7.08 375

(19) With reference to chart 5 below and FIG. 3a3f, the present invention is able to produce the low dimensional nano-material with a united size. Chart 5 illustrates the size of the low dimensional nano-material produced by different intercalating agents.

(20) TABLE-US-00005 CHART 5 Intercalating agent Size (nm) KHCO.sub.3 4.72 1.77 Li.sub.2CO.sub.3 4.46 1.27 K.sub.2CO.sub.3 7.54 2.78 LiOH 2.77 1.33 NaOH 3.85 1.11 KOH 2.99 1.25

(21) The above specification, examples, and data provide a complete description of the present disclosure and use of exemplary embodiments. Although various embodiments of the present disclosure have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those with ordinary skill in the art could make numerous alterations or modifications to the disclosed embodiments without departing from the spirit or scope of this disclosure.