▎ 摘　　要

NOVELTY - Preparing graphitic carbon nitride (g-C3N4) based metal free nanocomposites involves grounding, melamine (5 g) powder in mortar and pestle and placing into a ceramic crucible, then covering with a lid, and placing the crucible containing melamine in a muffle furnace and heated at different temperature with ramping rate of 20-550℃ for 4 hours. The resultant yellowish material is collected and cooled naturally at room temperature to obtained graphitic carbon nitride and grounded into fine light yellow powder. The graphitic carbon nitride is phosphorus doped by using 1-butyl-3-methylimidazolium hexafluorophosphate as a phosphorous source to obtain a phosphorous doped g-C3N4. A graphitic oxide (GO) is synthesized by stirring 2 g of powdered flake graphite and 1 g of sodium nitrate (NaNO3) into 100 ml sulfuric acid (H2SO4), in an ice-bath, added 6 g of potassium permanganate (KMnO4) to a suspension. USE - Method for preparing graphitic carbon nitride based metal free nanocomposites. ADVANTAGE - The method uses graphene, that acts as sink for the generated electrons of g-C3N4and minimizes electron hole pair recombination, thus improves photocatalytic performance, and exceptional honeycomb carbon geometry forms exceptional physicochemical properties and led to intense interest from different scientific disciplines. DETAILED DESCRIPTION - Preparing graphitic carbon nitride (g-C3N4) based metal free nanocomposites involves grounding, melamine (5 g) powder in mortar and pestle and placing into a ceramic crucible, then covering with a lid, and placing the crucible containing melamine in a muffle furnace and heated at different temperature with ramping rate of 20-550℃ for 4 hours. The resultant yellowish material is collected and cooled naturally at room temperature to obtained graphitic carbon nitride and grounded into fine light yellow powder. The graphitic carbon nitride is phosphorus doped by using 1-butyl-3-methylimidazolium hexafluorophosphate as a phosphorous source to obtain a phosphorous doped g-C3N4. A graphitic oxide (GO) is synthesized by stirring 2 g of powdered flake graphite and 1 g of sodium nitrate (NaNO3) into 100 ml sulfuric acid (H2SO4), in an ice-bath, added 6 g of potassium permanganate (KMnO4) to a suspension over a period of 2 hours on ice bath, then ultrasonicated for 25 minutes and allowed to react at room temperature for 2 hours. The temperature of the suspension is brought to 35℃ for 30 minutes, and added reaction mixture to a flask containing 100 ml distilled water and is heated at 70℃ for 15 minutes. The diluted suspension appears brown in color. The suspension is diluted to approximately 400 ml warm distilled water and treated with hydrogen peroxide (H2O2) to reduce the residual permanganate and manganese dioxide to colorless soluble manganese sulfate, and on treating with peroxide, suspension turn bright yellow and obtained graphitic oxide. The resultant mixture is centrifuged at 3500 revolutions/minute for 10 minutes and washed thoroughly with 5% hydrogen chloride (HCl) twice followed by washing with double distilled water until pH 6. The mixture is washed, and centrifuged at 4500 revolutions/minute for 10 minutes and dispersed in methanol followed by ultrasonication for 30 minutes. The final product is dried in oven at 50℃ for 48 hours, and prepared graphitic oxide (GO) is exfoliated by ethanol (70%) and dried again at 50℃, and dried GO is dissolved in 50 ml distilled water and added ammonia to maintain 10 pH and added 40 ml hydrazine and ultrasonicated for 2 hours. A resultant is centrifuged and dried at 50℃ to obtain a graphene (G) and the graphene oxide (GO), where 100 mg phosphorous doped g-C3N4is dissolved in 80 mL distilled water, while 1.0 mg GO or G is mixed with 20 mL distilled water. The two solutions are ultrasonicated separately for 1 hours and mixed GO or G and g-C3N4 dispersions and ultrasonicated for 2 hours. The product is obtained after freeze-drying and labelled as a phosphorous doped g-C3N4/GO and a phosphorous doped g-C3N4/G.