High Energy Transfer Efficiency Research Articles

Gadolinium oxide single crystals: Optical properties and radiation resistance

Large-size high optical quality Gd2O3 single crystals were grown from solution at T = 1145 °C by Czochralski method. XRD analysis showed that the crystal structure is characterized by a single cubic phase (С-phase). Absorption spectra and luminescence properties of Gd2O3 doped with impurity Tb3+ ion were studied. The absorption spectrum is determined by electronic transitions in Gd3+ ion (spectral region of 245–315 nm) and interband electron transitions below 240 nm. Intraconfigurational radiative f-f transitions from 5D4 level in Tb3+ ion are clearly manifested upon both UV- and X-ray excitation. At the same time, 6PJ → 8S7/2 radiative transitions in Gd3+ ions are completely absent. This fact indicates high efficiency of nonradiative energy transfer from Gd3+ to Tb3+ ions. Thermo-luminescent spectroscopy shows the absence of charge carrier trapping centers, which proves the perfection of its crystal structure. The crystal under study shows high radiation resistance to high-energy (E = 10 MeV, D = 105 kGy) electron beam. However, the effects of irradiation appear only in the photoluminescence excitation spectra and thermally stimulated luminescence.

Phycobilisome’s Exciton Transfer Efficiency Relies on an Energetic Funnel Driven by Chromophore–Linker Protein Interactions

The phycobilisome is the primary light-harvesting antenna in cyanobacterial and red algal oxygenic photosynthesis. It maintains near-unity efficiency of energy transfer to reaction centers despite relying on slow exciton hopping along a relatively sparse network of highly fluorescent phycobilin chromophores. How the complex maintains this high efficiency remains unexplained. Using a two-dimensional electronic spectroscopy polarization scheme that enhances energy transfer features, we directly watch energy flow in the phycobilisome complex of Synechocystis sp. PCC 6803 from the outer phycocyanin rods to the allophycocyanin core. The observed downhill flow of energy, previously hidden within congested spectra, is faster than timescales predicted by Förster hopping along single rod chromophores. We attribute the fast, 8 ps energy transfer to interactions between rod-core linker proteins and terminal rod chromophores, which facilitate unidirectionally downhill energy flow to the core. This mechanism drives the high energy transfer efficiency in the phycobilisome and suggests that linker protein-chromophore interactions have likely evolved to shape its energetic landscape.

Infrared Signatures of Phycobilins within the Phycocyanin 645 Complex.

Aquatic photosynthetic organisms evolved to use a variety of light frequencies to perform photosynthesis. Phycobiliprotein phycocyanin 645 (PC645) is a light-harvesting complex in cryptophyte algae able to transfer the absorbed green solar light to other antennas with over 99% efficiency. The infrared signatures of the phycobilin pigments embedded in PC645 are difficult to access and could provide useful information to understand the mechanism behind the high efficiency of energy transfer in PC645. We use visible-pump IR-probe and two-dimensional electronic vibrational spectroscopy to study the dynamical evolution and assign the fingerprint mid-infrared signatures to each pigment in PC645. Here, we report the pigment-specific vibrational markers that enable us to track the spatial flow of excitation energy between the phycobilin pigment pairs. We speculate that two high-frequency modes (1588 and 1596 cm-1) are involved in the vibronic coupling leading to fast (<ps) and direct energy transfer from the highest to lowest exciton, bypassing the intermediate excitons.

ATP-Enhanced Multistimuli-Responsive Förster Resonance Energy Transfer in Organic Coassemblies.

In recent years, ATP has emerged as an anionic biocomponent for the design of dynamic and stimuli-responsive supramolecular assemblies. Herein, we present ATP-enhanced Förster resonance energy transfer (FRET) in the coassemblies of pyrene-imidazolium amphiphiles with pyrene acting as an excellent donor for the coembedded acceptor dyes to generate tunable multiluminescent materials in aqueous solutions and in polymer and solid films. We achieved high energy transfer efficiency up to 95% even at a donor/acceptor (D/A) ratio of 100:1. By a simple variation of the D/A ratio, emission covering almost the whole range of the visible spectrum from blue to red including white light was obtained in solution and in solid and polymer films. Furthermore, the systems exhibited FRET ON/OFF features controlled by various stimuli such as temperature, pH, and metal ions. Most notably, a ratiometric and linear luminescence response to temperature and pH was observed. The stimuli-responsive tunable solid-state emission was further exploited in encryption-decryption applications.

Tunable luminescence and efficient energy transfer investigation of a borosilicate phosphor KBSi2O6: Bi3+, Eu3+ with hypersensitive thermal quenching

Energy transfer between Bi3+ and Eu3+ has undergone substantial research but Bi3+ and Eu3+ co-doped luminescent materials with high energy transfer efficiency for temperature sensing are rarely investigated until now. Herein, Eu3+ and Bi3+ co-doped KBSi2O6 phosphors were successfully synthesized by solid-state reaction method. The phase purity structure as well as the element distribution were carefully investigated through X-ray diffraction structural refinement and energy dispersive spectrometer analysis. The characteristic luminescence property and luminescence kinetics of KBSi2O6: Bi3+, Eu3+ were investigated. By the large spectra overlap between the emission spectrum of Bi3+ and excitation spectrum of Eu3+, the energy transfer from Bi3+ to Eu3+ can be inferred. The corresponding decrease of the emission intensity and decay time of Bi3+ in KBSi2O6: Bi3+, Eu3+ provided direct evidence for the effective energy transfer from Bi3+ to Eu3+. The interaction and energy transfer mechanism between Bi3+ and Eu3+ ions were also studied. By increasing the Eu3+ concentration in KBSi2O6: Bi3+, Eu3+, the color-tunable emission from blue to red can be realized. KBSi2O6: Bi3+, Eu3+ shows hypersensitive thermal quenching behavior and the maximum absolute sensitivity (Sa) and relative sensitivity (Sr) are determined to be 1.87 %K−1 and 2.895 %K−1, respectively. All of the above results imply that KBSi2O6: Bi3+, Eu3+ phosphor can be a color-tunable phosphor for optical temperature sensing.

Photo-induced energy transfer within donor−acceptor dipeptides: Towards an artificial light-harvesting hydrogel system

Well-defined relative orientations and distances between chromophores are prerequisites for high-efficiency energy transfer, which can generally be realized by regularly assembling short peptide compounds with different absorption wavelengths and luminescence positions. Herein, a series of dipeptides are designed and synthesized, where the dipeptides contain different chromophores with several absorption bands. A co-self-assembled peptide hydrogel is prepared for artificial light-harvesting systems. The photophysical properties and assembly behavior of these dipeptide-chromophore conjugates in solution and hydrogel are systematically studied. As a result of the three-dimensional (3-D) self-assembly feature, effective energy transfer between donor and acceptor in the hydrogel system is achieved. These systems exhibit high antenna effect at a high donor/acceptor ratio (2564:1), which is characterized by an increase in the fluorescence intensity. Further, multiple molecules with different absorption wavelengths can be co-assembled as energy donors in order to achieve a wide spectrum of absorption. The method allows flexible light-harvesting systems to be realized. The ratio of energy donors to acceptors can be adjusted arbitrarily, and constructive motifs can be selected based on the application.

Optimized Resonant Network Design for High Energy Transfer Efficiency of the WPT System

This paper proposes an active resonant network based on variable resonant capacitances to improve the operating performance of the LCC-S compensated topology in the wireless power transfer (WPT) system for electric vehicles under coil-misaligned conditions. By adjusting the series and parallel compensation capacitances on the transmitting side, the output voltage can be kept constant and the energy transfer efficiency can be improved under different coil offsets. The switch-controlled capacitors (SCCs) are used to change the compensation capacitances continuously. To find the proper compensation capacitances to achieve the excellent performance of the system, the optimization algorithm is applied, and the corresponding digital control strategy is described to regulate the equivalent capacitances of SCCs. Experimental results with a 2.7 kW power scale show that the output voltage is constant, and the operating efficiency is always over 90% in the WPT system with an active resonant network under different misalignment conditions. In addition, the system is delivering an equal amount of energy for all misalignments within the range of 80 mm, which improves the expected value of transferred energy by about 29%.

Lattice Distorted Rhodium Nanocrystals in Porous Nanofiber toward Aqueous Zinc-CO2 System

Directly harvesting hydrogen from water represents a green solution toward low-cost, high-efficiency, and sustainable electrochemical energy transfer and storage. Herein, a unique approach to allow maximization of the intrinsic activity and hydrogen adsorption/desorption kinetics with engineering a lattice of rhodium (Rh) for an aqueous zinc-CO2 system is reported. The enlarged Rh–Rh bonding and lattice relaxation of Rh species cause improvement of the adsorption/desorption kinetics of H*, which can directly affect the hydrogen evolution reaction (HER). An ultralow overpotential of 6.8 mV is achieved at a current density of 10 mA cm–2 from the permanent lattice relaxed Rh under acidic conditions. In a practical application in the aqueous zinc-CO2 system, its stable hydrogen generation performance is better than that of the benchmark platinum/carbon system. This work might open opportunities for the design and engineering of electrocatalysts for high-efficiency conversion from electric energy to hydrogen energy.

Phosphorescent Carbon Dots as Long-Lived Donors To Develop an Energy Transfer-Based Sensing Platform.

Employing long-lived luminescent materials to design a chemical sensing platform can eliminate real-time excitation and background fluorescence. However, the realization of long-lived emissions in aqueous media was limited to transition-metal complexes, doped quantum dots, organic crystals, and inorganic persistent phosphors, which suffer from the drawbacks of large size, expensive elements, and poor dispersibility. In this work, phosphorescent carbon dots (CDs) were covalently immobilized in a silica matrix (CDs@SiO2) to achieve afterglow emission in an aqueous dispersion. CDs@SiO2 with long lifetime (∼1.6 s) was utilized as an energy donor to fabricate nonradiative energy transfer systems with various organic dyes through the surface micelle self-assembly method. Benefiting from the high energy transfer efficiency between CDs@SiO2 and organic dyes, multicolor afterglow emissions were successfully obtained in aqueous media. As a proof of concept, a ratiometric phosphorescent probe using CDs@SiO2 as a donor and Hg2+-responsive rhodamine derivative as an acceptor was designed. Hg2+ triggered the energy transfer process between the donor-acceptor pair, leading to the sensitive detection of Hg2+ ions. The work presented here provides opportunities to develop chemical sensors with low background interferences and easily recognizable signals.

Ln-MOF Based Ratiometric Luminescent Sensor for the Detection of Potential COVID-19 Drugs.

Countless people have been affected by the COVID-19 pandemic on a global scale. Favipiravir, has shown potential as an effective drug for SARS-CoV-2, attracting scientists' attention. However, overuse of Favipiravir easily leads to serious side effects, requiring real-time monitoring in body fluids. Given this, a new lanthanide metal-organic framework (MOF) was prepared under solvothermal conditions from either Eu (Eu-MOF or (1)) or Tb (Tb-MOF or (2)) using the highly delocalized imidazoledicarboxylic acid linker H2 L (H2 L=5-(4-(imidazol-1-yl) phenyl) isophthalic acid) and could be successfully applied to selective optical detection of Favipiravir. In this MOF framework, the organic linker H2 L provides a high excitation energy transfer efficiency that can sensitize luminescence in lanthanides. In addition, through deliberate tuning of Eu/Tb molar ratio and reaction concentration in the lanthanide framework, ratiometric recyclable luminescent Eux Tb1-x -MOF nanoparticles with open metal sites have been constructed, which present a high detection sensitivity (Ksv =1×107 [M-1 ], detection limit is 4.63 nM) for Favipiravir. The detection mechanism is discussed with the help of Density Functional Theory (DFT) calculations that sheds light over the selective sensing of Favipiravir over other related COVID-19 drug candidates. Finally, to explore the practical application of Favipiravir sensing, MOF based thin films have been used for visual detection of Favipiravir and recycled 5 times.

High-efficiency energy transfer in the strong orange-red-emitting phosphor CeO2:Sm3+, Eu3.

High-efficiency energy transfer (ET) from Sm3+ to Eu3+ leads to dominant red emission in Sm3+, Eu3+ co-doped single-phase cubic CeO2 phosphors. In this work, a series of Sm3+ singly and Sm3+/Eu3+ co-doped CeO2 cubic phosphors was successfully synthesized by solution combustion followed by heat treatment at 800 °C in air. The crystal structure, morphology, chemical element composition, and luminescence properties of the obtained phosphors were investigated using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and photoluminescence analysis. Under 360 nm excitation, the Sm3+ singly doped CeO2 phosphor emitted strong yellow-red light at 573 nm (4G5/2-6H5/2) and 615 nm (4G5/2-6H7/2). Meanwhile, the CeO2:Sm3+, Eu3+ phosphors showed the emission characteristic of both Sm3+ and Eu3+, with the highest emission intensity at 631 nm. The emission intensity of Sm3+ decreased with increasing Eu3+ content, suggesting the ET from Sm3+ to Eu3+ in the CeO2:Sm3+, Eu3+ phosphors. The decay kinetics of the 4G5/2-6H5/2 transition of Sm3+ in the CeO2:Sm3+, Eu3+ phosphors were investigated, confirming the high-efficiency ET from Sm3+ to Eu3+ (reached 84%). The critical distance of energy transfer (RC = 13.7 Å) and the Dexter theory analysis confirmed the ET mechanism corresponding to the quadrupole-quadrupole interaction. These results indicate that the high-efficiency ET from Sm3+ to Eu3+ in CeO2:Sm3+, Eu3+ phosphors is an excellent strategy to improve the emission efficiency of Eu3+.

Structural and optical variation of pseudoisocyanine aggregates nucleated on DNA substrates

Coherently coupled pseudoisocyanine (PIC) dye aggregates have demonstrated the ability to delocalize electronic excitations and ultimately migrate excitons with much higher efficiency than similar designs where excitations are isolated to individual chromophores. Here, we report initial evidence of a new type of PIC aggregate, formed through heterogeneous nucleation on DNA oligonucleotides, displaying photophysical properties that differ significantly from previously reported aggregates. This new aggregate, which we call the super aggregate (SA) due to the need for elevated dye excess to form it, is clearly differentiated from previously reported aggregates by spectroscopic and biophysical characterization. In emission spectra, the SA exhibits peak narrowing and, in some cases, significant quantum yield variation, indicative of stronger coupling in cyanine dyes. The SA was further characterized with circular dichroism and atomic force microscopy observing unique features depending on the DNA substrate. Then by integrating an AlexaFluorTM 647 (AF) dye as an energy transfer acceptor into the system, we observed mixed energy transfer characteristics using the different DNA. For example, SA formed with a rigid DNA double crossover tile (DX-tile) substrate resulted in AF emission sensitization. While SA formed with more flexible non-DX-tile DNA (i.e. duplex and single strand DNA) resulted in AF emission quenching. These combined characterizations strongly imply that DNA-based PIC aggregate properties can be controlled through simple modifications to the DNA substrate’s sequence and geometry. Ultimately, we aim to inform rational design principles for future device prototyping. For example, one key conclusion of the study is that the high absorbance cross-section and efficient energy transfer observed with rigid substrates made for better photonic antennae, compared to flexible DNA substrates.

A tube-like Pd@coordination polymer with enhanced solar light harvesting for boosting photocatalytic H2 production in a wide pH range and seawater.

Coordination polymers (CPs) have emerged as promising candidates for photocatalytic H2 production owing to their structural tailorability and functional diversity. However, the development of CPs with high energy transfer efficiency for highly efficient photocatalytic H2 production in a wide pH range still faces many challenges. Here we constructed a novel tube-like Pd(ii) coordination polymer with well-distributed Pd nanoparticles (denoted as Pd/Pd(ii)CPs) based on the coordination assembly of rhodamine 6G and Pd(ii) ions and further photo-reduction under visible light irradiation. Both the Br- ion and double solvent play a key role in forming the hollow superstructures. The resulting tube-like Pd/Pd(ii)CPs exhibit high stability in aqueous solution with the pH range from 3 to 14 due to the high Gibbs free energies of protonation and deprotonation, which provides the feasibility of photocatalytic hydrogen generation in a wide pH range. Electromagnetic field calculations showed that the tube-like Pd/Pd(ii)CPs have a good confinement effect on light. Therefore, the H2 evolution rate could reach 112.3 mmol h-1 g-1 at pH 13 under visible light irradiation, which is far superior to those of reported coordination polymer-based photocatalysts. Moreover, such Pd/Pd(ii)CPs could also reach a H2 production rate of 37.8 mmol h-1 g-1 in seawater under visible light with low optical density (40 mW cm-2) close to morning or cloudy sunlight. The above unique characteristics make the Pd/Pd(ii)CPs possess great potential for practical applications.

Internet of Bio Nano Things-based FRET nanocommunications for eHealth.

The integration of the Internet of Bio Nano Things (IoBNT) with artificial intelligence (AI) and molecular communications technology is now required to achieve eHealth, specifically in the targeted drug delivery system (TDDS). In this work, we investigate an analytical framework for IoBNT with Forster resonance energy transfer (FRET) nanocommunication to enable intelligent bio nano thing (BNT) machine to accurately deliver therapeutic drug to the diseased cells. The FRET nanocommunication is accomplished by using the well-known pair of fluorescent proteins, EYFP and ECFP. Furthermore, the proposed IoBNT monitors drug transmission by using the quenching process in order to reduce side effects in healthy cells. We investigate the IoBNT framework by driving diffusional rate models in the presence of a quenching process. We evaluate the performance of the proposed framework in terms of the energy transfer efficiency, diffusion-controlled rate and drug loss rate. According to the simulation results, the proposed IoBNT with the intelligent bio nano thing for monitoring the quenching process can significantly achieve high energy transfer efficiency and low drug delivery loss rate, i.e., accurately delivering the desired therapeutic drugs to the diseased cell.

Detection of rabies virus via exciton energy transfer between CdTe quantum dots and Au nanoparticles.

Rabies is a fatal encephalitis caused by the rabies virus. The diagnosis of the disease depends in large part on the exposure history of the victim and clinical manifestations of the disease. Rapid rabies diagnosis is an important step in its prevention and control. Therefore, for accurate and timely diagnosis and prevention of rabies, we developed nanomaterials for a novel photoelectrochemical biosensing approach (PBA) for the rapid and reliable diagnosis of rabies virus. This approach uses high-efficiency exciton energy transfer between cadmium telluride quantum dots and Au nanoparticles and is low cost, and easy to miniaturize. By constructing PBA, rabies virus can be detected quickly and with a high degree of sensitivity and specificity; the minimum detection concentration limit for rabies virus is approximately 2.16 ffu/mL of rabies virus particles, or 2.53 × 101 fg/mL of rabies virus RNA. PBA could also detect rabies virus in the brain and lung tissue from rabid dogs and mice with better sensitivity than RT-PCR.

Construction and application of the polyelectrolyte-based sequential artificial light-harvesting system

In this work, we have designed and synthesized a cyano-substituted p-phenylenevinylene derivative (PPTA), which can self-assemble into positively charged nanoparticles in an aqueous solution with a deep green fluorescence. An anionic polyelectrolyte material guar gum modified by carboxylic acid (GP5A) was chosen to build an artificial light-harvesting system (LHS) through self-assembly with PPTA, in which two acceptors Eosin Y (EY) and Nile red (NiR) were loaded into the PPTA-GP5A assemblies through electrostatic interaction and Van der Waals force. By adjusting the molar ratio of PPTA-GP5A/EY at 1:0.004, the one-step artificial LHS can exhibit high energy transfer efficiency (ΦET) (38.9%) and antenna effect (AE) (4.6). Subsequently, with the addition of NiR, the ΦET and AE of the two-step sequential artificial LHS were calculated to be 71.9% and 13.5, respectively. Moreover, the two-step artificial LHS constructed by the polyelectrolyte material GP5A can be used as a nanoreactor to photocatalyst alkylation of C-H bonds of phenyl vinyl sulfone (PVS) and tetrahydrofuran (THF) in water with a yield of 42%. Therefore, we have constructed an artificial LHS with two-step energy transfer based on polyelectrolytes through the electrostatic interaction to improve energy transfer efficiency, which can also be used as a nanoreactor for photocatalysis.

Design and Analysis of a Novel Adjustable SVAWT for Wind Energy Harvesting in New Energy Vehicle

The new energy vehicle is a robust measure to solve the problem of global warming. However, the new energy vehicle generally has the disadvantages of short mileage and difficulty in finding public chargers. The combination of wind energy harvest and new energy vehicle can be conducive to the promotion of the new energy vehicle. This paper proposes a novel adjustable Savonius vertical axis wind turbine (SVAWT). It contains three parts: an energy absorption module, an energy recovery module, and an energy conversion module. The energy absorption module includes four blades with staggered distribution in two layers. The overlap ratio of the blades can be adjusted by the wind speed, which can ensure the SVAWT has a higher energy transfer efficiency. The energy recovery module adjusts the overlap ratio of the blades without interruption by utilizing the self-rotation and the orbital revolution of the gears. The energy conversion module converts mechanical energy into electric energy and supplies power for the vehicle after adjustment by the voltage regulator module. Based on actual operating data, it can be found that the variation trend of power of the blades absorbing is consistent with wind speed and increases with the wind speed. Under four actual operating conditions, the root mean square value of the blades absorbing power are 7.0 W, 7.1 W, 3.9 W, and 5.1 W, respectively. These results reveal that the proposed novel adjustable SVAWT has high recovery power potential and can provide a valuable solution to the practical applications of wind energy harvesting.

A ratiometric lysosome-targeted fluorescent probe for imaging SO2 based on the coumarin-quinoline-julolidine molecular system

Similar to nitric oxide (NO) molecule, carbon monoxide (CO) molecule and hydrogen sulfide (H2S) molecule, sulfur dioxide (SO2) is also considered to be another important endogenous signaling molecule. SO2 derivatives are widely used as food antioxidants and antimicrobial agents. However, SO2 is also a toxic environmental pollutant and intake of elevated levels of sulfites can lead to diarrhea, low blood pressure and allergic and asthmatic reactions in susceptible people. The specific physiological effects and transformation processes of SO2 and its derivatives are not well understood due to the limitations of existing detection methods. Therefore, it is an urgent need to develop highly sensitive, high-resolution, real-time in situ assays. Herein, we specifically designed a ratiometric near-infrared fluorescent probe CQT for detecting SO2 derivatives. After the reaction of CQT with HSO3−/SO32−, a gradual decrease in red fluorescence at 662 nm accompanied by an enhanced blue fluorescence at 489 nm, reaching a detection range of 2.8–80 μM. In addition, we found that CQT had high energy transfer efficiency, large Stokes shift and low detection limit, which meant that CQT could sensitively monitor small changes of SO2 concentration in cells and accurately target lysosomes.

Investigation of structural and optical properties: Tm2O3/Dy2O3 codoping in P2O5-MgO-NaF-CaF2 glass

Rare earth-doped glass is regarded as an excellent luminescent material and has been widely used in solid-state lighting. Here, the Tm3+/Dy3+ co-doped phosphate glasses revealed an increasing trend in density as the raising of Tm3+ contents, and the Urbach energies were 0.242∼0.374 eV based on transmission spectra. Under the 362 nm excitation, the white light with the chromaticity coordinates that were close to the value of standard white light was produced. The electric dipole-dipole interaction plays a major role in the energy transfer process from Tm3+ to Dy3+, and the glass exhibited a very high energy transfer efficiency of 64.44% according to the fluorescence spectra. Furthermore, the luminescent intensity of Tm3+/Dy3+ co-doped glasses at 150°C can still keep approximately 85.4% of its initial intensity and the glasses displayed excellent moisture-resistance (99.2%). Overall, the prepared Tm3+/Dy3+ co-doped glass exhibited potential applications in the field of W-LED and display devices.

High sensitivity and multicolor tunable optical thermometry in Bi3+/Eu3+ co-doped Ca2Sb2O7 phosphors

Currently, with increasing demand for non-contact fluorescence intensity ratio-based optical thermometry, a novel phosphor with high-efficiency, dual-emitting centers, and differentiable temperature sensitivity is more and more urgent to develop. In this work, an efficient dual-emitting center optical thermometry with high sensitivity and multicolor tunable in Ca2Sb2O7:Bi3+, Eu3+ phosphor is firstly designed and successfully prepared. Under 330 nm excitation, the fabricated phosphor presents the featured and distinguishable emissions of Bi3+ and Eu3+ ions. The high efficiency energy transfer from Bi3+ to Eu3+ ions is proved and its corresponding mechanism belongs to dipole-dipole interaction. By modulating the ratio of Bi3+/Eu3+, the multicolor changes from blue to pink are realized. Based on the discriminative thermal quenching behavior between Bi3+ and Eu3+, the fluorescence intensity ratio of Eu3+ to Bi3+ in Ca2Sb2O7 samples illustrates excellent optical thermometry performance from 298 to 523 K. The maximum absolute sensitivity (Sa) and relative sensitivity (Sr) reach as high as 0.2773 K−1 at 523 K and 2.37% K−1 at 448 K, respectively. Notably, the discriminated surrounding temperature can be directly confirmed by observing the emitting color from purple to orange-red with the temperature increase from 298 to 523 K. Furthermore, the as-prepared phosphor materials also demonstrate outstanding repeatability and excellent reversibility. These results exhibit that the designed Ca2Sb2O7:Bi3+, Eu3+ phosphors have great promising applications in the field of non-contact optical temperature thermometry and thermochromic.