▎ 摘　　要

NOVELTY - Rare earth phosphor comprises calcium- carbon trioxide-europium-potassium complex represented by formula (I), comprising calcium nitrate tetrahydrate, potassium carbonate, europium nitrate hexahydrate, graphene oxide, carbon quantum dots, where the molar ratio of calcium nitrate tetrahydrate to potassium carbonate is 0.70-0.90:0.05-0.20, the molar ratio of calcium nitrate tetrahydrate to europium nitrate hexahydrate is 0.70-0.90:0.05-0.20 and the mass ratio of graphene oxide to carbon quantum dots is 1-2:1-4. USE - Used as rare earth phosphor. ADVANTAGE - The phosphor has simple method, realizes the initial improvement of luminous efficiency and improves the stability. DETAILED DESCRIPTION - The rare earth phosphor is calcium- carbon trioxide-europium-potassium complex represented by formula Ca(1-2x)CO3:x (Eu3+, K+) (I), comprising calcium nitrate tetrahydrate, potassium carbonate, cerium nitrate hexahydrate, graphene oxide, carbon quantum dots, where the molar ratio of calcium nitrate tetrahydrate to potassium carbonate is 0.70-0.90:0.05-0.20, the molar ratio of calcium nitrate tetrahydrate to cerium nitrate hexahydrate is 0.70-0.90:0.05-0.20 and the mass ratio of graphene oxide to carbon quantum dots is 1-2:1-4. INDEPENDENT CLAIM are also included for: (1) preparing rare earth phosphor comprising (i) accurately providing calcium nitrate tetrahydrate and potassium carbonate, completely dissolving with deionized water, (ii) accurately measuring 0.05-0.20 mol of cerium nitrate hexahydrate solution into calcium nitrate tetrahydrate solution, stirring and mixing evenly, (iii) adding dropwise potassium carbonate solution to the calcium nitrate tetrahydrate solution, completely precipitating calcium ions and cesium ions together, (iv) filtering above solution, using a suction filtration device, and washing the precipitate with deionized water, (v) placing precipitate in a constant temperature drying oven for drying at 60-120 degrees C for 120-300 minutes to obtain rare earth phosphor powder precursor, (vi) accurately providing potassium carbonate into precursor, adding a small amount of deionized water, mixing, grinding evenly, transferring to crucible, placing it into a high temperature furnace, roasting at 150-550 degrees C for 180-480 minutes and (vii) grinding calcined product to obtain rare earth phosphor sample; and (2) preparing graphene phosphor comprising (I) accurately providing rare earth phosphor and reduced graphene oxide-carbon quantum dot composite with a mass ratio of 1:0.0005-0.005, placing it in a mortar, adding deionized water, making the sample paste, mixing and grinding to make it uniform, (II) placing mixed and ground sample in a constant temperature drying oven, drying at 60-240 degrees C for 2-8 hours, (III) grinding sample and collecting to obtain graphene phosphor.