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An activators lattice migration strategy was customized for developing tunable- luminescence phosphors in Ce doped β -Ca 3 (PO 4) 2 families. By dint of XAFS and DFT calculations, we predicted the local crystal environment of each lattices and migrated Ce3+ from M(3) to another strengthened site with a lower coordination number, shorter bonding bond length, and greater polyhedral distortion, M(5). Relevant parameters were identified for dealing with interference caused by the electronegativity change during structural modification and some applications emerged for display and information security. [Display omitted] • Activators lattice migration strategy was proposed for tunable-emission phosphors. • The specific occupation and 5 sites local crystal environment of Ce were predicted. • Ce3+ was migrated to another site with a strengthened crystal field by modification. • The relative intensity of ε CFS and ε NE determined an abnormal emitting mechanism. • Δ D (C e 3 +) were identified to deal with the interference of electronegativity difference. The luminescent properties of phosphors are determined by the electronic configuration of their activators and the crystal environment in which they are embedded. By manipulating the site-selective occupancy of activators, we can coordinately control the local crystal field and electron cloud distribution to master the movement of emission wavelength and obtain a color-tunable phosphor. The system of β -Ca 3 (PO 4) 2 is an excellent carrier for crystal-site engineering to modify luminescent performance. It has five distinct crystal sites and a strong photoluminescence response. However, due to low doping concentration and structural complexity, the specific occupation of Ce remains unknown. We discussed the specific position of Ce in this study and proposed a novel activators lattice migration strategy for controlling the relative strength of crystal field splitting (CFS) and the nephelauxetic effect (NE) to control luminescence properties. By combining X-ray Absorption Fine Structure (XAFS) with DFT calculation, we predicted the local environment of each crystal lattice and migrated Ce3+ from M(3) to a strengthened crystal field site with a lower coordination number, shorter bonding bond length, and greater polyhedral distortion, M(5) , resulting in phosphors with tunable luminescence emission. Relevant parameters Δ D (C e 3 +) were identified for dealing with interference caused by the electronegativity difference during a structural modification. Some potential applications emerged as a supplement and an intriguing QR-code and response program for epidemic prevention were demonstrated. This structure–activity relationship-based strategy provides new inspiration for designing luminescent materials with tunable emission and a broader range of applications. [ABSTRACT FROM AUTHOR]

An anti-defect engineering strategy, inspired by photocatalytic and photovoltaic materials, was proposed to develop high-efficiency phosphors in whitlockite families. Significant enhancement of photoluminescence intensity (2.46 times), thermal stability (87.92% at 150 °C), cathodoluminescence intensity (3.34 times), quantum efficiency (IQE sharply up to nearly 100%) were simultaneously realized by constructing a rigid structure and removing vacancy defects. The developed phosphors exhibited promising applications in the fields of warm-white LEDs, plant growth lighting and information security. [Display omitted] • Anti-defect engineering strategy is proposed to develop high-efficiency phosphors. • The internal quantum yield is sharply improved from 38.90% to 99.07%. • The mechanism of improvement is revealed by defect-related characterizations. • DFT calculation shows the positive role of Debye temperature and alkali metal ions. • Promising applications in warm-white LEDs / plant-growth lighting are demonstrated. Lacking an effective strategy to simultaneously address the challenges of quantum efficiency, luminescence intensity and thermal stability has become the key bottleneck for further development and large-scale application of solid-state lighting technology. Herein, inspired by the defect-engineering used in photoelectrocatalytic and photovoltaic materials, we acted in a diametrically opposite way and unprecedentedly proposed an anti-defect engineering strategy to develop high-efficiency phosphors. By constructing a rigid structure and introducing alkali metals M to remove cation vacancy defects, similar to building blocks and jigsaw puzzle, we developed three groups of whitlockite phosphors, namely Ca 3- x Sr x (PO 4) 2 :Ce3+, Ca 3 (PO 4) 2 :Ce3+, M and (Ca 0.5 Sr 0.5) 3 (PO 4) 2 :Ce3+,Na+,Mn2+, and synchronously realized the significant enhancement of photoluminescence intensity (2.46 times), thermal stability (87.92% at 150 °C), cathodoluminescence intensity (3.34 times), quantum yield (from 38.90% to 99.07%). We characterized the defect concentration by positron annihilation technique (PAT), and calculated Debye temperature (ΘD) and simulated the occupation of M according to DFT theory to reveal the improvement mechanism. Some advanced applications were also explored in this work, including warm-white LEDs, plant growth lighting and information security. The anti-defect engineering proposed in this work may contribute to the further development of high-efficiency phosphors for the next-generation smart solid-state lighting technologies. [ABSTRACT FROM AUTHOR]

The constructed high-efficient cyan-emitting phosphors establish a bifunctional platform involving high-color-quality lighting and anti-counterfeiting application. [Display omitted] • Ca 8 ZnY(PO 4) 7 :Eu2+ phosphors exhibited a broad cyan-emitting spectra (FWHM = 78 nm). • The quantum yield of Ca 8 ZnY(PO 4) 7 :Eu2+ phosphor is as high as 72.11 %. • The CRI value of warm w -LED devices was greatly enhanced from 83.9 to 90.5. • The transparent anticounterfeiting film held great potentials in packaging field. Constructing the broad-band emitting luminescent materials with high quantum yield is of great significance towards their widespread applications. Herein, series of Eu2+ activated, whitlockite-type Ca 8 ZnY(PO 4) 7 phosphors are developed towards bifunctional platform involving the white LED and anti-counterfeiting field. Benefiting from the typical 5d-4f transitions among Eu2+ ions, the broad asymmetric cyan-emission spectra (FWHM = 78 nm) is generated under 365 nm excitation with a highest quantum yield of ∼72.11 %. The optimal doping concentration of Eu2+ ions in the Ca 8 ZnY(PO 4) 7 host is determined as 4 % and the concentration quenching mechanism is mainly attributed to a dipole–dipole interaction. Impressively, after exploiting the newly discovered cyan-emitting phosphors Ca 8 ZnY(PO 4) 7 :Eu2+, the CRI value of as-prepared warm w -LED devices is remarkably enhanced from 83.9 to 90.5. Moreover, the w -LED exhibits an applicable correlated color temperature (CCT = 4176 K) and good color stability. Additionally, the transparent anticounterfeiting film is fabricated based on the highly efficient phosphors and soluble PVA, which presents anticounterfeiting performances due to their bright cyan emission upon UV light. Notably, their sustainability, excellent flexibility and foldability provide more possibilities applied for anticounterfeiting field. These results suggest the highly efficient phosphors Ca 8 ZnY(PO 4) 7 :Eu2+ are promising bifunctional luminescent platforms, for both high-color-quality lighting and anticounterfeiting applications. [ABSTRACT FROM AUTHOR]

Color-tunable manganese/europium/tellurium-doped halide perovskites are synthesized and can be used to post processing fibers for LEDs and anti-counterfeiting and detection materials. [Display omitted] • Color-tunable manganese/europium/tellurium-doped halide perovskites are synthesized. • Perovskites are composited with flexible fibers to prepare luminescent fibers. • The perovskite crystals can be used to fabricate light-emitting diode lamps. • Expanding the application of compound flexible fiber and perovskite. All-inorganic metal halide perovskites exhibit excellent optoelectronic properties, and cesium lead halide perovskites have been the most extensively studied perovskites. Despite their excellent performance, the toxicity of CsPbX 3 (X = halide) perovskites is a significant hurdle in the path of their widespread commercialization, posing challenges for large-scale applications. The lead-free characteristic and inherent air stability of Cs 2 NaBiX 6 render them promising alternatives to CsPbX 3 perovskites. Herein, we report the lead-free double perovskite crystals (PCs) derived from Cs 2 NaBiCl 6 incorporating doping with three distinct elements. This doping strategy effectively regulates the emission wavelength of Cs 2 NaBiCl 6 , with particular emphasis on Eu-doped and Te-doped Cs 2 NaBiCl 6 , which have been scarcely reported in previous studies. Light-emitting diodes (LEDs) have been fabricated by these perovskite crystals. The white LED was prepared by Mn-doped Cs 2 NaBiCl 6 with a high color rendering index (CRI) of 95.5. In addition, fiber paper, composed of aramid chopped fibers (ACFs) and polyphenylene sulfide (PPS), exhibits sustained fluorescence characteristics in different environments under an ultraviolet lamp when post-processed with perovskite. The photoluminescence quantum yield (PLQY) of flexible luminescent fibers prepared from Cs 2 (NaBi) 0.95 Mn 0.10 Cl 6 PCs and ACFs/PPS fibers can reach 18.27 %. This fluorescent fiber paper holds potential applications in fields such as fluorescent anti-counterfeiting and intelligent wearable devices. By irradiating with a specific wavelength of the laser, the damaged area of fiber textiles can be quickly detected based on changes in fluorescence intensity. The integration of luminescent crystals and fibers into functional fabrics opens avenues for utilization in high-performance textile testing and other domains. [ABSTRACT FROM AUTHOR]

We synthesized Tb3+-doped Cs 4 MnBi 2 Cl 12 perovskite crystals by the crystallization. These PCs have extremely strong PL intensity and stability at high temperatures, sunshine and low temperature. The Tb3+-doped Cs 4 MnBi 2 Cl 12 PCs have excellent luminescent properties and stability and can be used in luminous composite fibers and white LED devices field. [Display omitted] • Experiment under normal pressure environment, cost reduction and facile operation. • The Cs 4 Mn(Bi 1- x Tb x) 2 Cl 12 PCs have excellent stability in air. • The PCs have a excellent fluorescence performance with a PLQY of 25.45%. • The PCs were applied to ACFs/PPS composite paper with orange emission. • The composite paper can maintain stability in different real environments. In recent years, all-inorganic perovskites have attracted considerable research attention. However, the advancement of lead-based perovskites has encountered substantial challenges, redirecting current research efforts toward lead-free alternatives. In this study, we synthesized novel Cs 4 MnBi 2 Cl 12 perovskite crystals at 80 °C. Furthermore, Tb3+ ions were introduced to enhance the fluorescence properties and stability of the as-prepared perovskite crystals (PCs). The photoluminescence quantum yield (PLQY) of Tb3+-doped PCs was 25.45 % (∼598 nm), making a two-fold increase compared with the original PCs. In the PCs, [BiCl 6 ]3− octahedrons serve as energy collectors, generating excitons, while [MnCl 6 ]4− octahedrons function as luminescence centers of the receptor. Owing to their entirely inorganic composition, the PCs exhibited exceptional stability under sunlight and across a wide range of temperatures. Finally, we applied the PCs to fiber composite paper and an light-emitting diode (LED) device, which retained their specific stability after the modification. The findings of this study offer nover insight for incorporating perovskites into fiber applications and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Self-reduction of Eu3+ was realized in three-dimensional BaMgP 2 O 7 host using the energy-saving method in air environment. Incorporating charge compensators Li+/K+ can precisely control the self-reduction process, and its mechanism was elucidated using a charge compensation model. Furthermore, this work explored some advanced applications, such as plant growth, fingerprint visualization, and screen printing. [Display omitted] • Eu3+ self-reduction was achieved in three-dimensional pyrophosphate under atmospheric without hazardous gas. • Hetero-valence Eu2+/Eu3+ are obtained and luminescent properties were investigated. • Controlling high-valent ions' self-reduction using Li+/K+ charge compensators. • Advanced applications such as plant growth, fingerprint visualization, and screen printing are explored. • Ecofriendly luminescent materials are pivotal for advancing phosphor applications. The exploitation of ecofriendly luminescent materials is crucial for advancing phosphor applications. Herein, Eu3+ self-reduction was performed using the energy-saving high-temperature solid-phase method in air environment. Achieving controllable self-reduction is challenging for high-valent rare-earth and transition metal ions. Therefore, we incorporate charge compensators, such as Li+/K+ to control the reaction and obtain hetero-valent Eu2+/Eu3+. Experimental results indicate that charge compensators can eliminate vacancies, suppress self-reduction, and affect luminescence properties. Moreover, a nonequivalent substitution mechanism about self-reduction using a charge compensation model is discussed here. Notably, Eu2+ shows a strong blue narrow-band emission peak at 410 nm with a full width at half maxima of 34 nm, overlapping well with that of chlorophyll. The phosphors are nontoxic and exhibit high contrast under ultraviolet light, which can be utilized for forensic science detection. The precisely controllable self-reduction of phosphors can contribute to the development of next-generation smart and green materials. Advanced applications of the phosphors for plant growth, fingerprint visualization, and screen printing are also explored. [ABSTRACT FROM AUTHOR]

Light and stress dual-responsive piezoelectric semiconductor NaNbO 3 /g-C 3 N 4 heterojunction exhibits excellent water flow weak force-driven piezo-photocatalytic degradation of various antibiotics and drugs. [Display omitted] • NaNbO 3 /g-C 3 N 4 heterojunction were prepared by high-energy wet ball-milling. • The formation of heterojunction allows an intimate interfacial interaction. • It exhibits excellent water flow-triggered piezo-photocatalytic activity. • Piezo-photocatalytic TC degradation efficiency reaches 87.3 % within only 10 min. • Polarization and heterojunction synergistically promotes photocharge separation. Photocatalysis is a green and sustainable technology for pollution control, but has the disadvantage of fast recombination of photogenerated charges. Piezocatalysis has recently been widely studied for environmental purification, while it always involves the high-frequency ultrasonic vibration that inevitably causes high energy consumption. In this work, a water flow weak force-driven piezo-photocatalytic system that integrates light and stress dual-responsive components is developed in NaNbO 3 /g-C 3 N 4 heterojunction. As piezoelectric semiconductors with both piezoelectric and semiconducting properties, the piezoelectric polarization field of NaNbO 3 and g-C 3 N 4 induced by high-speed stirring not only produces strong polarization, but also directly triggers efficient piezocatalysis, and the spatial separation of interfacial carriers is accompanied by the formation of type-II heterojunction. The above merits endow NaNbO 3 /g-C 3 N 4 with outstanding water flow-triggered piezo-photocatalytic degradation for various antibiotics and drugs, including tetracycline hydrochloride (TC), oxytetracycline (OXY), ciprofloxacin (CIP), chloramphenicol (CHL), and paracetamol (PAR). Specifically, the TC degradation efficiency reaches up to 87.3 % within only 10 min, which makes it one of the best piezo-photocatalysts, even exceeding those irradiated by ultrasound. This work may open up a reference perspective for the engineering design of dual-active piezo-photocatalyst systems, and for the in-situ purification of diversified wastewaters on the basis of hydrodynamic properties. [ABSTRACT FROM AUTHOR]

Manganese dioxides (MOs) are excellent microwave absorbing materials and have been used as substrates or catalysts for enhanced degradation of organic compounds. In this study, we extended our research on using birnessite (Birn), a type of MOs, for the degradation of tetracycline (TC) in aqueous solution under microwave induction (MI). The Birns were fabricated to achieve different ratios of Mn(II)/Mn(III)/Mn(IV) in the crystal structure. Their physical and chemical characteristics were determined by X-ray diffraction, field-emission environmental scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray absorption fine structure spectra, and a microwave network analyzer. Their removal of TC under MI was evaluated under different physicochemical conditions. Lower solution pH, higher MI power, and higher Mn(II) and Mn(III) in the structure resulted in more TC removal. And the Birns are regenerable. LC–MS analyses confirmed the presence of degradation intermediates. The better performances of TC removal by Birns under MI was attributed to the high magnetic spin moment of Mn(II) and Mn(III) in the structure that has higher MI response. [ABSTRACT FROM AUTHOR]