Rare Earth Phosphates Research Articles

A simple and fast strategy for rare earth doped phosphors prepared by 980 nm laser thermal effect

The phosphors synthesize by the sol-gel method show low cost and good homogeneity, but it also requires furnace annealing at high-temperatures. This report uses a 980 nm laser annealing strategy to replace the furnace annealing in the sol-gel combustion synthesis. The fast laser annealing can improve the preparation efficiency of rare earth doped phosphor. Er3+/Li+ co-doped Y2O3 nanocrystals are synthesized by laser annealing strategy. The structures and spectral properties of the phosphors prepared by laser annealing are studied. The phosphors prepared by laser annealing have the same crystal structure and spectral properties as those organized by furnace annealing. In addition, phosphors can be heated into crystals using a high-power 980 nm laser. Under 980 nm excitation, the crystal prepared by laser annealing shows a much stronger fluorescence intensity than phosphors.

Maximizing the exploitation of phosphogypsum wastes using soaking technique with citric acid, recovering rare-earth and residual phosphate contents

Maximizing the exploitation of phosphogypsum wastes using soaking technique with citric acid, recovering rare-earth and residual phosphate contents

Independent dual-responsive luminous composite fibers with controllable full-color emissions

Accumulated ultraviolet (UV) under high temperature is prone to cause photoaging, skin burns, and even induce skin cancers during outdoor activities. Fiber-based wearable sensors with color-tunable luminescent ability are urgently demanded for real-time monitoring of human health conditions to enhance personal awareness of these hazards. To achieve tunable full-color emission, a set of three primary colors (red, green, and blue) of rare-earth doped persistent luminescent phosphors are successfully synthesized. After simply mixing them with particular ratios, a tunable full-color emission system can be realized. Herein, by integrating the thermochromic dyes, photochromic dyes, and luminescent phosphors directly into polyacrylonitrile (PAN) matrix, novel thermo-UV-sensing composite fibers with color-tunable luminescent ability are prepared via the facile wet-spinning process. The obtained fibers can be switched among four different colors with brilliant reversible color changes in response to temperature and UV irradiation both independently and in combination. Besides, the fibers can emit tunable emissions under in full spectral range 365 nm excitation. This work paves the way for as-prepared fibers for diverse applications including energy-free, wearable real-time monitors of the temperature/UV, and high-level information encryption.

Selective separation of lanthanide group in spent NiMH battery acidic leaching solutions

A novel selective separation of lanthanide group (Ln) known as rare earth elements (REEs) from acidic leaching solutions of spent nickel metal hydride (NiMH) batteries was examined using precipitation at low pH with disodium phosphate, Na2HPO4, as precipitation agent. The acidic leaching solutions containing lanthanides (La, Ce, and Nd) and base metals (Ni, Cd, Mn, Fe, Al, and Zn) were from spent NiMH batteries subject to subcritical water extraction (SWE) process using 0.5 mol/L of HCl, HNO3, and H2SO4 solution, respectively. The effects of important parameters such as the molar ratio of lanthanides to phosphate ions, Ln/P, to form precipitates of lanthanide phosphates (Ln(PO4)), pH and temperature were investigated. The recovery efficiency of lanthanides increased when decreasing Ln/P, while increased with increasing pH and temperature. The decrease in the concentration of Ln remaining in HCl and HNO3 leaching solutions was proportional to the decrease in the P concentration in leaching solutions, while different results were found in the leaching solution of H2SO4 due to the formation of another insoluble lanthanide mineral, double sulfate (NaLn(SO4)2·H2O). This separation process demonstrated that the high-purity lanthanide group including La, Ce, and Nd from spent NiMH batteries could be obtained simply by adding phosphate ions at low pH. It is efficient, effective, and selective for critical rare metals recovery from spent NiMH batteries.

Thermally-induced structural phase transition in rare earth orthophosphate nanocrystals for highly sensitive thermal history paints

It was demonstrated that he temperature-driven irreversible structural phase transformations in the Eu3+ activated LaPO4, La0.5Y0.5PO4, and YPO4 nanocrystals can be used for the thermal history measurements over the 200oC-1000oC temperature range. Increase of the temperature caused significant changes in the Eu3+ local surroundings and, in consequence modified the intensity and the emission spectra. We showed that the intensity ratio of Eu3+ 5D0→ 7F2 to 5D0→7F1 emissions may serve as a highly-sensitive indicator of the highest temperature to which the nanocrystals were exposed to. The relative sensitivity of Y0.5La0.5PO4:2 %Eu3+ based thermal history paint was as high as 0.8 %/°C at 1000 °C. The thermal history surface map of the square steel plate covered with Y0.5La0.5PO4:2 %Eu3+ paint, heated locally at one of the corner is obtained as proof-of-concept experiment. The proposed ratiometric readout strategy facilitates measurement and enhances the accuracy of thermal history analysis.

Towards control facilities for mimicking plant growth optimum action spectrum: Efficient near-ultraviolet to far-red light-conversion in Cr3+-doped rare-earth aluminate phosphors

Phosphor-converted materials have recently become promising candidates for the next generation horticulture and agriculture owing to their ability to overcome the daily sunlight limitations. Here, Tb0.7La0.3ZnAl11O19:Cr3+ (TLZA:Cr3+) was prepared by a high-temperature solid state method, which showed high near-ultraviolet (NUV) and green light to far-red conversion efficiencies. In the optimized TLZA:6%Cr3+ phosphor, the energy transfer from the host to the dopant was carried out through a dipole-quadrupole interaction mechanism with an efficiency of 99.62 %. The phosphor-converted light-emitting diode (pc-LED) devices were fabricated by combining TLZA:6%Cr3+, blue and red phosphors with 380 nm NUV-chips, which modulated the optimum action spectrum for indoor plant growth. TLZA:6%Cr3+ luminescent film laminated glass (LFLG) adjusted the composition of the solar spectrum to red/blue light ratio of 3:1 and promoted plant growth in outdoor horticultural greenhouses. Therefore, the pc-LED and LFLG fabricated with the TLZA:6%Cr3+ phosphor in this work are excellent spectral control devices for indoor plant lighting and outdoor horticultural facilities, respectively.

Review of Rare-Earth Phosphate Materials for Nuclear Waste Sequestration Applications.

Several materials have or are currently being investigated for nuclear waste sequestration applications, including crystalline ceramic oxides, glasses, and glass-ceramic composites. Rare-earth phosphates have been investigated extensively for this application owing to the range of structures that the hydrous or anhydrous versions can adopt as well as the fact that naturally occurring rare-earth phosphates have been found to contain U or Th. The purpose of this mini-review is to discuss (generally) the properties that must be considered when identifying nuclear wasteform materials and (more specifically) the structure and properties of rare-earth phosphates with special attention being given to the resistance of these materials to radiation-induced structure damage. The last section of the mini-review contains an introduction to the development of glass-ceramic composite materials that contain rare-earth phosphate crystallites dispersed in a glass matrix. These composite materials have been suggested to be superior to using just glass or ceramic materials for nuclear waste sequestration applications owing to improved waste loading capabilities.

Effect of Eu3+, Bi3+, and Li+ doping on luminescent property of GdNbO4

We investigated the emission properties of Eu3+-doped GdNbO4-based oxide phosphors, aiming at improving the Eu3+ emission by codoping of Bi3+ and Li+. Eu3+ singly doped, Eu3+ and Bi3+ doubly doped, and Eu3+, Bi3+, and Li+ triply doped GdNbO4 were prepared using a high-temperature solid-state reaction method. The red-orange emissions from Eu3+ in the singly doped samples are significantly improved by the codoping of Bi3+, mainly due to the energy transfer from Bi3+ to Eu3+. The additional codoping of Li+ is found to increase the Eu3+ emission significantly. This improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity. A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+ in GdNbO4 does not change significantly with the codoping of Bi3+ and Li+. Our results indicate that Li+ doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4 phosphors.

Preparation of photoluminescent nanocomposite ink for detection and mapping of fingermarks.

Simple and efficient detection and mapping method based on a strong turn-on fluorescent pigment was developed for fingerprint analysis. We present a phosphor powder characterized by strong emission which is useful to achieve better fingerprint detection on multicolored or photoluminescent surfaces, such as currency notes characterized by optically changeable inks and highly fluorescent positions, because it offers better contrast and reduce the difficulty of background interference. Novel photochromic ink was prepared to establish a fingerprinted colorless film onto cellulose documents with green emission for anticounterfeiting applications as illustrated by photoluminescence spectra. Inorganic/organic nanoscale composite ink was prepared from rare-earth doped aluminate phosphor nanoparticles (PNPs; 27-49 nm) dispersed in a polyacrylic acid binding agent. PNPs were dispersed efficiently in polyacrylic acid to generate a colorless mark. The produced photochromic inks were spray-coated onto off-white paper sheets enclosing invisible fingermarks, and then exposed to thermofixation. Photochromic film was detected on paper surface presenting a transparent appearance under visible daylight and switchable to green under UV light. The CIE Lab parameters and photoluminescence spectra were studied under visible light and ultraviolet irradiation. The fingerprinted sheets showed fluorescence band at 517 nm upon excitation at 366 nm, showing a bathochromic shift and reversible photochromism without fatigue. The morphologies of pigment phosphor particles and fingerprinted sheets were inspected. The rheological properties of ink and mechanical behavior of the fingerprinted paper samples were explored. HIGHLIGHTS: Novel smart ink with alkaline-earth aluminate and polyacrylic acid was developed. Dual-mode fluorescent photochromism was presented for latent fingerprint analysis. Off-white fingerprinted films under daylight showed color change to green under UV. Fluorescence band monitored at 517 nm upon excitation at 366 nm. Fluorescent fingermark on paper sheets demonstrated good photostability.

Cost-effective micro-CT system for non-destructive testing of titanium 3D printed medical components

Micro-CT imaging can be used as an effective method for non-destructive testing (NDT) of metal 3D printed parts-including titanium biomedical components fabricated using laser powder-bed-fusion (LPBF). Unfortunately, the cost of commercially available micro-CT scanners renders routine NDT for biomedical applications prohibitively expensive. This study describes the design, manufacturing, and implementation of a cost-effective scanner tailored for NDT of medium-size titanium 3D printed biomedical components. The main elements of the scanner; which include a low-energy (80 kVp) portable x-ray unit, and a low-cost lens-coupled detector; can be acquired with a budget less than $ 11000 USD. The low-cost detector system uses a rare-earth phosphor screen, lens-coupled to a dSLR camera (Nikon D800) in a front-lit tilted configuration. This strategy takes advantage of the improved light-sensitivity of modern full-frame CMOS camera sensors and minimizes source-to-detector distance to maximize x-ray flux. The imaging performance of the system is characterized using a comprehensive CT quality-assurance phantom, and two titanium 3D-printed test specimens. Results show that the cost-effective scanner can survey the porosity and cracks in titanium parts with thicknesses of up to 13 mm of solid metal. Quantitatively, the scanner produced geometrically stable reconstructions, with a voxel size of 118 μm, and noise levels under 55 HU. The cost-effective scanner was able to estimate the porosity of a 17 mm diameter titanium 3D-printed cylindrical lattice structure, with a 0.3% relative error. The proposed scanner will facilitate the implementation of titanium LPBF-printed components for biomedical applications by incorporating routine cost-effective NDT as part of the process control and validation steps of medical-device quality-management systems. By reducing the cost of the x-ray detector and shielding, the scan cost will be commensurate with the overall cost of the validated component.

Facile development of novel photochromic luminescent composite fiber for anticounterfeiting and wearable UV detector

Photo-responsive fibers with persistent luminescence and reversible color switching properties are highly in demand owing to their potential application in information security, camouflage, optical sensors, and anticounterfeiting. Herein, a facile strategy to develop novel photochromic luminescent fiber (PLF) via a wet-spinning process was presented. The resulting fiber is composed of rare-earth luminescent phosphors SrAl2O4: Eu2+, Dy3+ (SAO) and Y2O2S: Eu3+, Mg2+, Ti4+ (YOS) as the luminescence sources, photochromic yellow microcapsules (PYM) as the reversible photochromic materials, and the matrix is polyacrylonitrile (PAN). The as-prepared fiber emits unique yellow luminescence with long afterglow under ultraviolet (UV) light. Furthermore, the fiber shows a quick and reversible color response to UV stimulation. Benefiting from the excellent reversible photochromic behavior, and persistent luminescence, the photochromic luminescent fiber can be adopted in various applications such as smart textiles, anticounterfeiting, and wearable UV detection devices.

Characterization of nano-minerals and nanoparticles in supergene rare earth element mineralization related to chemical weathering of granites

AbstractIon adsorption-type rare earth element (REE) ore deposits in South China are a major source of heavy rare earth elements (HREE) around the world, which are of considerable economic and strategic significance. In these ores, REE is enriched in the clay minerals, specifically kaolinite and halloysite, which are derived from their parent granitoid by the weathering process. However, the mechanisms of supergene REE mineralization remain unclear. We investigated the nature and origin of supergene REE mineralization, based on a nanoscale study of a typical REE-mineralized granite regolith profile (ΣREEmax = 1201 ppm) in the Dazhou super-large, ion adsorption-type REE deposit, Guangxi Province, South China. Bulk mineralogical and geochemical analyses, coupled with novel nano-characterization techniques [i.e., hollow fiber flow field-flow fractionation inductively coupled plasma-mass spectrometry (HF5-ICP-MS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM)], were used to determine the nature of the nano-minerals and nanoparticles in the regolith samples. X-ray diffraction and SEM-EDS analyses revealed that ion-adsorption clay minerals are dominated by platy-shaped kaolinite and rod-like halloysite (10 and 7 Å) within the regolith. The average clay mineral contents decreased from 38 to 15% from the fully weathered horizon to the semi-weathered horizon, whereas the proportion of halloysite increased in the clay mineral fraction in the deep horizons. The REE-bearing nanoparticles consist predominantly of macromolecules of organic matter (2–5 nm) and clay minerals (5–40 and 40–80 nm) according to the HF5-ICP-MS analysis. There is a close association between REE and Al contents in particles with sizes of 5–40 nm in the semi-weathered horizons and 40–80 nm in the highly weathered horizons, which indicates that nanoscale clay minerals (halloysite and kaolinite, respectively) are important REE carriers. In addition, nanoscale secondary REE mineral phases, including oxide, silicate, and phosphate, were identified by the SEM and TEM observations. These phases are typically adsorbed onto the surfaces of clay minerals, specifically rod-like halloysite, but have different occurrences in the regolith profile. Cesium-oxide (cerianite) and Ce-silicate (cerite) occur mainly in the upper horizon of the regolith profile, whereas low-crystallinity REE phosphates [rhabdophane-(La)] occur mainly in the lower horizon of the profile. Our results indicate that nano-minerals and nanoparticles affect REE enrichment and fractionation during granite weathering. Migration and accumulation of REE-bearing nano-minerals were caused by leaching and neoformation of REE-bearing nano-minerals during secondary precipitation. These processes contribute to the formation of supergene REE mineralization in granite regolith.

Photoluminescence study of reddish orange emitting Eu3+ activated LaPO4 Nanoparticles via hydrothermal method

Lanthanum phosphate (LaPO4) belongs to the family of rare earth phosphates characterized as a fluorescence material. Europium ion is known for its orange –red fluorescence. In order to include orange –red fluorescence for pure white light generation we are doping LaPO4 with Eu3+. The crystalline planes are identified from the XRD pattern show that the particles have monoclinic structure with pure LaPO4. The addition of sodium ions to the LaPO4: Eu3+ sample it is found that the luminescence property gets increased. It is also found that reversal of the emission spectrum intensity takes place for the sodium doped sample which indicates that Eu3+ ions are located in a highly symmetric environment.

Peptide functionalized Dynabeads for the magnetic carrier separation of rare-earth fluorescent lamp phosphors

Novel separation processes for end of life fluorescent lamp phosphors could greatly contribute towards a more sustainable rare-earth element market. Furthermore, surface-binding peptides bound to magnetic carriers are a promising biotechnological tool for selective particle separation processes. In this work, we investigate the magnetic carrier separation of the three most common rare-earth fluorescent lamp phosphors, facilitated by Dynabeads functionalized with previously identified selectively surface-binding peptides. We present an active ester-mediated coupling to chemically immobilize the peptides on amine and carboxylic acid coated beads. We report on the impact of the peptide functionalization on the surface properties of the beads, based on zeta potential investigations of variously functionalized beads and a Raman spectroscopic structural study of the investigated peptides. Fluorometrically, we show that the phosphor removal strongly depends on the medium and the surface coating of the beads. Furthermore, the Raman spectroscopic evidence of various simultaneously present disulfide bond conformations indicates an equilibrium of multiple peptide conformations and/or the presence of intermolecular disulfide bonds. Moreover, we found that carboxylic acid coated Dynabeads have a high affinity for the red phosphor Y2O3:Eu3+and based on the determined isoelectric points we hypothesize that this is driven by electrostatic surface interactions. This work can contribute towards novel rare-earth phosphor separation processes and towards a better understanding of magnetic carrier separation processes facilitated by surface-binding peptides.

129Xe NMR analysis of pore structures and adsorption phenomena in rare-earth element phosphates

Rare-earth elements (REEs) are indispensable in various applications ranging from catalysis to batteries and they are commonly found from phosphate minerals. Xenon is an excellent exogenous NMR probe for materials because it is inert and its 129Xe chemical shift is very sensitive to its local physical or chemical environment. Here, we exploit, for the first time, 129Xe NMR for the characterization of porous structures and adsorption properties of REE phosphates (REEPO4). We study four different REEPO4 samples (REE = La, Lu, Sm and Yb), including both light (La and Sm) and heavy (Lu and Yb) as well as diamagnetic (La and Lu) and paramagnetic (Sm and Yb) REEs. 129Xe resonances are very sensitive to the porous structures and moisture content of the REEPO4 samples. In the samples treated at a lower temperature (80 °C), free water hinders the access of hydrophobic xenon into small mesopores, but the treatment at a higher temperature (200 °C) removes the free water and allows xenon to explore the mesopores. Based on a standard two-site exchange model analysis of the variable-temperature 129Xe chemical shifts, as well as its proposed, novel modification for paramagnetic materials, the average mesopore sizes were determined. The size was the largest (79 nm) for the La sample with mixed monazite (70%) and rhabdophane (30%) phases and the smallest (6 nm) for the Yb sample with pure xenotime phase. The mesopore sizes of the Lu and Yb samples (12 and 6 nm) differed by a factor of two regardless of their similar xenotime phase. The 129Xe NMR analysis revealed that the heats of adsorption of the samples are similar, varying between 8.7 and 10.1 kJ/mol. For diamagnetic samples, computational modelling confirmed the order of magnitude of the chemical shifts of Xe adsorbed on surfaces and therefore the validity of the two-site exchange model analysis. Overall, 129Xe NMR provides exceptionally versatile information about the pore structures and adsorption properties of REEPO4 materials, which may be very useful for developing the extraction processes and applications of REEs.

Selective formation of neodymium phosphate from iron-neodymium magnet waste

Neodymium-iron-boron alloy, Nd2Fe14B, is used as a material for magnets. Neodymium is one of the valuable and expensive rare earth elements and is often recovered to reduce costs and environmental impact. Recently, a method for recovering neodymium as neodymium phosphate from mixed solutions was reported. This method was very useful because the main component of rare earth ores is rare earth phosphates, and there are well-established methods for refining rare earths from rare earth phosphates. This study attempts to obtain neodymium phosphate using acid to dissolve waste magnets, reducing agent, phosphoric acid, and pH adjuster. The diluted acid (hydrochloric acid and nitric acid), amount of ascorbic acid and phosphoric acid, and the pH values were studied to clear the suitable conditions. The color of the heat-treated product, the precipitate yield, and the Fe/Nd molar ratio indicated that a low concentration of acid is suitable and ascorbic acid is required. Excessive use of phosphoric acid improved the precipitate composition. The high pH value decreased the selectivity of neodymium phosphate due to the easy formation of iron phosphate and hydroxide. The process addressed in this study is very promising because it does not require heating at high temperatures or special reagents.

Current research art of rare earth compound modified SiC-CMCs for enhanced wet-oxygen corrosion resistance

Silicon carbide fiber reinforced silicon carbide ceramic matrix composites (SiC-CMCs) currently present wide application potential as thermal structure component in aero-engine. To solve the wet-oxygen corrosion induced degradation of SiC-CMCs attract growing global attention. In this work, the main preparation methods via introduction of rare earth compound like rare earth phosphates, rare earth oxides, rare earth silicates and rare earth silicide carbides into SiC-CMCs matrix and interphase and their microstructures, mechanical properties and wet-oxygen corrosion resistance are summarized in details. Finally, the challenges and prospects of rare earth compound modified SiC-CMCs are proposed.

A novel highly thermal-stable red-emitting CaGdSbWO8:Eu3+ phosphor with scheelite structure for high CRI w-LEDs,security ink, and latent fingerprint

Recently, rare-earth doped phosphors have been newly developed and applied in hot issues such as phosphor-converted light-emitting diodes (pc-LEDs), anti-counterfeiting, and fingerprint visualization. Herein, an Eu 3+ -activated CaGdSbWO 8 (CGSW) red phosphor was synthesized by a high-temperature solid-state reaction. The phosphors can exhibit narrow red-light emission at 614 nm due to the electric dipole transition 5 D 0 → 7 F 2 of Eu 3+ . Impressively, this phosphor has excellent thermal stability, its emission intensity of optimum sample doped with 0.30 Eu 3+ remained 90.61% at 420 K and thermal quenching temperature exceeds 480 K. The Commission International del’Eclairage (CIE) chromaticity coordinates of CGSW:0.30Eu 3+ are (0.662, 0.338) with a high color purity (98.5%). The fabricated white light diode (w-LED) has a high color rendering index (91.4) and a low correlated color temperature (4986 K) with CIE coordinates (0.343, 0.327). Further experimental results showed that the prepared security ink can be applied to anti-counterfeit labels and information encryption. The latent fingerprint developed by CGSW:0.30Eu 3+ phosphor present the excellent selectivity and contrast. The level 1–3 structural characteristics of latent fingerprints could be well identified under ultraviolet irradiation. Therefore, the Eu 3+ -activated CGSW red-emitting phosphor has broad application prospects due to its excellent luminescence properties. • Novel CaGdSbWO 8 :Eu 3+ phosphors have been synthesized via high-temperature solid-state method. • The CaGdSbWO 8 :Eu 3+ phosphors with scheelite structure have good thermal stability ( T 0.5 >480 K). • The w-LED fabricated by the phosphor exhibits a high CRI value of 91.4 and a good CCT of 4986 K. • The applications in security ink and latent fingerprint of CaGdSbWO 8 :Eu 3+ phosphors are investigated in details.

The Occurrence of Primary REE Minerals and Their Para genesis within S-Type Granite and Quartz Vein, South Bangka, Bangka Belitung Islands, Indonesia

Primary rare earth element (REE) minerals known as carbonate and phosphate were identified in some localities. The carbonate type consists mainly of parasite, allanite, and bastnaesite, while REE phosphate group comprises mainly monazite and xenotime. They are accompanied by thorite and zircon. REE-bearing quartz vein is associated with cassiterite, pyrite, chalcopyrite, sphalerite, and tourmaline. The hydrothermal fluid that plays a role in REE mineral precipitation is subdivided into three stages: early (> 316oC - 316oC), medium (< 316oC – 210oC), and late (<210oC190oC). The δ18O range which is 12, 7 ‰ – 13 ‰, and the δ34S range are 3, 9 ‰ – 5, 5 ‰ indicate that the origin of hydrothermal fluid comes from mixing fluids of both meteoric and magmatic sources, and also influenced by metamorphic waters. While the source of sulphur is granitic and sedimentary rocks. REE phosphate is thought to have formed in the early magmatic crystallization stage except for monazite formed in the medium magmatic-hydrothermal and late hydrothermal stages. Primary REE carbonate may have formed in a medium hydrothermal-magmatic stage except for parasite and allanite, they may have formed in late-stage hydrothermal. Chalcopyrite and sphalerite seem to be associated with REE minerals in the medium and late hydrothermal stages

Optimization of the Pechini-derived synthesis of rare-earth free aluminum borate phosphors presenting tunable white emission

The present study is dedicated to the development of aluminum borate luminescent powders which appear as promising and more environmental-friendly than conventional phosphors. The different steps of the luminescent powder synthesis, in particular the precursors (inorganic and organic) ratios and calcination conditions, are adjusted by studying the resulting optical features to get a broader and warmer white emission. As shown in previous works, the photoluminescence emission originates from polycyclic aromatic hydrocarbons (PAH) trapped in the inorganic aluminum borate matrix. Morphological and structural properties of the particles remain otherwise identical for every optimized parameter. The aluminum borate powder synthesized in these optimized conditions exhibits a wide and intense emission band under near-UV excitation. These structural and optical properties combined with time-resolved photoluminescence measurements demonstrate that the adjustments of the synthetic process allow the formation and trapping of more and different emitting centers. The modulation of the excitation wavelength (from 305 to 405 nm) leads to a tunable photoluminescence emission characterized by a large band lying between 400 and 700 nm. This feature, associated with the use of secure and abundant precursors makes aluminum borate powders very interesting phosphors for optical applications.