Lanthanum hydroxide /lanthanum oxide/calcium silicate/graphitic carbon nitride particulate crystalline nanocomposite

Patent metadata

Field	Value
Publication number	US-12486177-B1
Application number	US-202519221146-A
Country	US
Kind code	B1
Filing date	May 28, 2025
Priority date	May 28, 2025
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

A La(OH)3/La2O3/CaSiO3/g-C3N4 particulate crystalline nanocomposite including: a hexagonal lanthanum hydroxide (La(OH)3) crystalline phase; a lanthanum oxide (La2O3) crystalline phase; a monoclinic calcium silicate (CaSiO3) crystalline phase; and, a graphitic carbon nitride (g-C3N4) crystalline phase, wherein at least a fraction of the g-C3N4 is in the form of mesoporous nanosheets.

First claim

The invention claimed is:

1 . A particulate crystalline nanocomposite comprising:
a hexagonal lanthanum hydroxide (La(OH) 3 ) crystalline phase; a lanthanum oxide (La 2 O 3 ) crystalline phase; a monoclinic calcium silicate (CaSiO 3 ) crystalline phase; and, a graphite carbon nitride (g-C 3 N 4 ) crystalline phase, wherein at least a fraction of the graphitic-C 3 N 4 is in the form of mesoporous nanosheets.

2 . The particulate crystalline nanocomposite according to claim 1 , wherein the ratio by weight of CaSiO 3 to g-C 3 N 4 to the sum of La(OH) 3 and La 2 O 3 in the particulate crystalline nanocomposite is about (0.8-1.2):(0.8-1.2):(0.8-1.2).

3 . The particulate crystalline nanocomposite according to claim 1 , wherein the particulate crystalline nanocomposite comprises acicular particles of La(OH) 3 , La 2 O 3 and CaSiO 3 .

4 . The particulate crystalline nanocomposite according to claim 1 , wherein the particulate crystalline nanocomposite comprises acicular particles of La(OH) 3 , La 2 O 3 and CaSiO 3 having a median length of from about 40 to about 100 nanometers (nm), as determined by transmission electron microscopy (TEM).

5 . The particulate crystalline nanocomposite according to claim 1 , wherein the particulate crystalline nanocomposite comprises aggregates of the mesoporous nanosheets of g-C 3 N 4 with nanoparticles of La(OH) 3 , La 2 O 3 and CaSiO 3 .

6 . The particulate crystalline nanocomposite according to claim 1 , wherein at least about 80 weight percent (wt. %) of the g-C 3 N 4 is in the form of mesoporous nanosheets.

7 . The particulate crystalline nanocomposite according to claim 1 , wherein the particulate crystalline nanocomposite has a surface area of from about 60 to about 100 m 2 /g, as determined by Brunauer-Emmett-Teller (BET) analysis.

8 . The particulate crystalline nanocomposite according to claim 1 , wherein the particulate crystalline nanocomposite has a surface area of from about 70 to about 90 m 2 /g, as determined by BET analysis.

9 . The particulate crystalline nanocomposite according to claim 1 , wherein the particulate crystalline nanocomposite has an average pore diameter of from about 10 to about 25 nm, as determined by Barrett-Joyner-Halenda (BJH) desorption analysis.

10 . The particulate crystalline nanocomposite according to claim 1 , wherein the particulate crystalline nanocomposite has a pore volume of from about 0.1 to about 0.4 cm 3 /g, as determined by BJH desorption analysis.

11 . The particulate crystalline nanocomposite according to claim 1 , wherein the particulate crystalline nanocomposite has a pore volume of from about 0.1 to about 0.3 cm 3 /g, as determined by BJH desorption analysis.

12 . The particulate crystalline nanocomposite according to claim 1 , wherein the particulate crystalline nanocomposite has a hysteresis loop of Type H3 (International Union of Pure and Applied Chemistry (IUPAC) Classification), as determined by N 2 adsorption-desorption analysis at 77 Kelvin (K).

13 . A method of preparing the particulate crystalline nanocomposite as defined in claim 1 , the method comprising:
forming a solution of a calcium salt and an alkali metal silicate in a solvent including water and a C 1 -C 4 alkanol; heating the solution at a temperature of from about 150 to about 250 degrees Celsius (° C.) to form a dry product of CaSiO 3 ; forming g-C 3 N 4 by heating urea in a closed vessel at a temperature of from about 500 to about 700° C.; dispersing the CaSiO 3 , g-C 3 N 4 , and La 2 O 3 in a polar protic solvent and heating the dispersion at a temperature of from about 150 to about 250° C. at a pressure of from about 2 to about 8 bar; and, separating the solid crystalline nanocomposite from the heated dispersion.

14 . The method according to claim 13 , wherein the calcium salt is selected from the group consisting of calcium sulfate (CaSO 4 ), calcium nitrate (Ca(NO 3 ) 2 ), calcium chloride (CaCl 2 ), and calcium acetate (Ca(CH 3 COO) 2 ).

15 . The method according to claim 14 , wherein the calcium salt is calcium nitrate (Ca(NO 3 ) 2 ).

16 . The method according to claim 13 , wherein the alkali metal silicate is selected from the group consisting of lithium metasilicate (Li 2 SiO 3 ), sodium metasilicate (Na 2 SiO 3 ), potassium metasilicate (K 2 SiO 3 ), and mixtures thereof.

17 . The method according to claim 13 , wherein the solution of a calcium salt and an alkali metal silicate is formed in a solvent including water and a C 1 -C 2 alkanol, wherein the ratio by weight of water to the C 1 -C 2 alkanol is from about 0.5:1 to about 2:1.

18 . The method according to claim 13 , wherein the polar protic solvent is selected from the group consisting of mono(C 1 -C 4 )alkyl ethers of ethylene glycol.

19 . The method according to claim 13 , wherein dispersing the CaSiO 3 , graphitic-C 3 N 4 , and La 2 O 3 in the polar protic solvent comprises:
forming a mixture of the CaSiO 3 , g-C 3 N 4 , La 2 O 3 , and the polar protic solvent; and, sonicating the mixture.

20 . The method according to claim 13 , wherein the dispersion is heated at a temperature of from about 150 to about 250° C. and at a pressure of from about 3 to about 6 bar.

Assignees

• Imam Mohammad Ibn Saud Islamic Univ

Inventors

• Abdulkhair Babiker Yagoub Elhadi
• Omran Mohamed Khairy Abdel Fattah

Classifications

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title

• C01P2004/04

  obtained by TEM, STEM, STM or AFM · CPC title

• C01P2006/14

  Pore volume · CPC title

• C01P2002/76

  by a space-group or by other symmetry indications · CPC title