Preparation method of environment-friendly economic luminescent carbon quantum dot

[0034] Example 1: Weigh 1 g of bagasse and add it to 20 ml of double distilled water. The reaction solution was put into a stainless steel reaction kettle lined with 50ml PTFE, heated in an electric oven at a constant temperature of 180°C for 1h to obtain a light yellow solution containing carbon quantum dots. After the solution is naturally cooled, filter with medium-speed filter paper to remove insoluble black precipitates, centrifuge at 15000g to remove large particles, collect the supernatant and inject it into a dialysis bag with a molecular cut-off of 1000Da for dialysis. The dialysis time is 72h, and it is changed every 12h. water. The dialysis product was subjected to rotary evaporation to obtain a concentrated solution. The concentrated solution was freeze-dried to powder at -50°C with a yield of 0%.

[0035] Example 2: Weigh 1g of bagasse and add it to 20ml of 0.6M sodium hydroxide aqueous solution. The reaction solution was put into a stainless steel reaction kettle lined with 50ml PTFE, heated in an electric oven at a constant temperature of 180°C for 1h to obtain a light yellow solution containing carbon quantum dots. After the solution is naturally cooled, filter with medium-speed filter paper to remove insoluble black precipitates, centrifuge at 15000g to remove large particles, collect the supernatant and inject it into a dialysis bag with a molecular cut-off of 1000Da for dialysis. The dialysis time is 72h, and it is changed every 12h. water. The dialysis product was subjected to rotary evaporation to obtain a concentrated solution. The concentrated solution was freeze-dried to powder at -50°C to obtain carbon quantum dots with high fluorescence performance. The yield was 2.17%.

[0036] Example 3: Weigh 1g of bagasse and add it to 20ml of 0.8M sodium hydroxide aqueous solution. The reaction solution was put into a stainless steel reaction kettle lined with 50ml PTFE, heated in an electric oven at a constant temperature of 180°C for 2h to obtain a light yellow solution containing carbon quantum dots. After the solution is naturally cooled, filter with medium-speed filter paper to remove insoluble black precipitates, centrifuge at 15000g to remove large particles, collect the supernatant and inject it into a dialysis bag with a molecular cut-off of 1000Da for dialysis. The dialysis time is 72h, and it is changed every 12h. water. The dialysis product was subjected to rotary evaporation to obtain a concentrated solution. The concentrated solution was freeze-dried to powder at -50°C to obtain carbon quantum dots with high fluorescence performance, with a yield of 3.24%.