Preparation of carbon dots using aminoquinoline as nitrogen source as full ultraviolet bands absorber and application of LED UV leakage protection

LED has the advantages of small size, low power consumption, instant lighting, etc., but there is a risk of ultraviolet leakage. Long-term exposure to ultraviolet rays can lead to skin pigmentation, photoaging and additional hazards. Carbon dots (CDs) are excellent material for UV-light absorber because of their multi-functional groups and extreme stability. In this paper, A-CDs which have wide absorption range from 200 to 500 nm were prepared by one-pot hydrothermal carbonization. Then, 3&4A-CDs is prepared in two ways, CDs mixing and raw material mixing, which with average and efficient absorption efficiency both in UVA bands and UVB bands. After 180 h of accelerated aging and switched the pH value, ultraviolet absorption intensity of 3&4A-CDs still remained above 97% and 99%, and the emission wavelength did not alter. Finally, 3&4A-CDs@CMC films were synthesized and the 0.45 wt% 3&4A-CDs@CMC film could reach 100% absorption in the full UV bond. After 180 h of accelerated aging experiments, ultraviolet absorption intensity of 3&4A-CDs@CMC film still remained above 95%. Due to the extremely excellent ultraviolet absorption efficiency of the 3&4A-CDs, the 0.45 wt% 3&4A-CDs@CMC film can effectively avoid the leakage of ultraviolet light without affecting the visible light emitting effect of LED. At present, the synthetic process of 3&4A-CDs is simple, low cost and environmentally friendly.