The optical sensitive detection of molybdate ions by layered europium hydroxides

Abstract A mild and effective way working over a wide pH range (from 2 to 12) to detect selectively trace amounts of molybdate ions in aqueous solutions in a short time was realized by the antenna effect between the molybdate ions and the layered europium hydroxide (LEuH). The efficient energy transfer from molybdate ions to LEuH allowed 0.1 g LEuH to detect concentration as low as 100 ppm in 30 min. According to the exploration of different experimental conditions, the photoluminescence (PL) intensity of Eu3+ is gradually enhanced with the increased adsorption for molybdate ions. When the quantity of molybdenum adsorbed is within a certain range, the multiple of PL increase has an exponential function relation with the adsorption quantity providing a new idea to detect molybdate ions in industry.