Molybdate-based red phosphor for ultraviolet-excited white light LED (light-emitting diode) and preparation method of molybdate-based red phosphor

[0018] Example 1

[0019] Weigh 1.96 mmol Y(NO 3 ) 3 · NH 2 O is dissolved in deionized water, and 0.02 mmol Eu 2 O 3 Dissolved in concentrated nitric acid and heated to evaporate to remove excess nitric acid, Eu(NO 3 ) 3 · 6H 2 O is soluble in Y(NO 3 ) 3 In the solution and magnetically stirred, then 0.143 mmol (NH 4 ) 6 Mo 7 O 24 ·4H 2 O was dissolved in deionized water, and then (NH 4 ) 6 Mo 7 O 24 ·4H 2 O solution is slowly added to the Y(NO 3 ) 3 And Eu(NO 3 ) 3 Then add ammonia water dropwise to adjust the pH to about 9 to obtain a mixed solution containing white precipitation of molybdate, and then put it into a polytetrafluoroethylene reactor for hydrothermal reaction at 160 ℃ for 36 h. The resulting product is washed with water , Centrifuge to remove impurities, then dry in an oven at 85 ℃ for 20 hours, and finally roast the product in a muffle furnace at 800 ℃ for 8 hours to obtain the final product.

[0020] Example 2

[0021] Weigh 1.96 mmol Y(NO 3 ) 3 · NH 2 O and 0.04 mmol Eu(NO 3 ) 3 · 6H 2 O was dissolved in deionized water and stirred magnetically, then 0.143 mmol (NH 4 ) 6 Mo 7 O 24 ·4H 2 O is dissolved in deionized water, and then (NH 4 ) 6 Mo 7 O 24 ·4H 2 O solution is slowly added to the Y(NO 3 ) 3 And Eu(NO 3 ) 3 Then add ammonia water dropwise to adjust the pH to about 9 to obtain a mixed solution containing white precipitate of molybdate, and then put it into a polytetrafluoroethylene reactor for hydrothermal reaction at 180 ℃ for 24 h, and the resulting product is washed with water , Centrifuge to remove impurities, then dry in an oven at 80 ℃ for 24 hours, and finally roast the product in a muffle furnace at 900 ℃ for 2 hours to obtain the final product.

[0022] figure 1 It is a red pink Y synthesized after hydrothermal reaction at 180 ℃ for 24 hours and roasting 2 MoO 6 :Eu 3+ X-ray powder diffraction pattern. The phase search found that the resulting product

[0026] Example 3

[0027] Weigh 0.98 mmol Y 2 O 3 And 0.02 mmol Eu 2 (CO 3 ) 3 Dissolve in excess dilute nitric acid, adjust the pH to near neutral with ammonia water, and dissolve 0.143 mmol (NH 4 ) 6 Mo 7 O 24 ·4H 2 The O solution was slowly added dropwise to the above-mentioned solution being stirred, and then ammonia water was added dropwise to adjust the pH to about 8 to obtain a mixed solution containing white precipitate of molybdate, and then put it into the polytetrafluoroethylene reactor at 170 ℃ After 30 hours of hydrothermal reaction, the resulting product was washed with water and centrifuged to remove impurities, and then dried in an oven at 70°C for 24 hours. Finally, the product was roasted in a muffle furnace at 850°C for 6 hours to obtain the final product.