Electrocatalytic nitrate reduction reaction to ammonia (eNO3RR) is an eco-friendly technology for the treatment of nitrate (NO3)-polluted water. An optimized bimetallic metal-organic framework material of Cu0.33Co0.67-BDC (H2BDC = 1,4-benzene dicarboxylic acid) was proposed as an efficient electrocatalyst for eNO3RR with the outstanding NH3 yield of 207.68 μmol∙h1cm2 and faradic efficiency of 77.95%. The electrocatalytic stability and durability of Cu0.33Co0.67-BDC for eNO3RR are demonstrated by NH3 yield and FE both fluctuating in an extremely narrow range during ten eNO3⁻RR cycles and a stable 10 h amperometric current-time test. The electrocatalytic mechanism is revealed as a synergistic effect between Cu(Ⅱ) and Co(Ⅱ) active sites. Cu0.33Co0.67-BDC is also designed as an anode to construct with Zn metal as a cathode into a zinc-nitrate (Zn-NO3⁻) battery. The Zn-NO3⁻ battery outstands itself for electrical energy supply with an impressive open circuit voltage of 1.62 V (vs. Zn/Zn2+), a power density of 1.59 mW cm−2 and a limiting current density of 4.68 mA cm−2. Two tandem Zn-NO3⁻ batteries can power four parallel LEDs simultaneously, supporting the practical capability of electrical power supply. This work provides an innovative approach for developing integrated "NO3⁻-pollution removal-energy supply" technologies.

The accumulation of nitrate/nitrite (NOx-) in wastewater poses a threat on ecological safety. Electrocatalytic NOx- reduction to ammonia (NOx-RR) is feasible to realize green ammonia production. This work developed a 2D copper metal-organic framework of Cu-BDC (H2BDC = 1,4-benzene dicarboxylic acid) as an efficient electrocatalyst for NOx-RR, exhibiting high-performance with the NH3 yield of 71.20 mu mol h- 1 cm-2 and a Faraday efficiency of 80.9 % at -0.746 V (vs. RHE) for NO2- RR, and the NH3 yield of 130.16 mu mol h- 1 cm- 2 and a Faraday efficiency of 67.42 % at -0.946 V (vs. RHE) for NO3- RR. Isotope labelled 14NO3- and 15NO3- produced 14NH4+ and 15NH4+, supporting the formation of NH3 comes from the NO3- RR. In three NOx-RR cycles, all NH3 yields and Faraday efficiencies show a slight change, demonstrating an excellent electrocatalytic stability in NOx-RR. Our work provides a new material platform for the elimination of nitrate and nitrite through electrocatalytic reduction.

The development of innovative luminescent materials for lighting and display applications is an important research field. In this work, we have employed an anionic condensation approach to discover a novel oxonitridosilicate synthesized via Li metal flux. LaSi2N3O crystallizes in the orthorhombic space group Pna2(1) (a = 7.82609(6), b = 18.24908(15), and c = 4.86567(5) & Aring;) with a structure consisting of [Si6N12O2] ribbons cross-linked by [SiN3O] tetrahedra. This follows previously reported structural rules for a series of condensed rare-earth oxonitridosilicates, and discovery of this relatively simple composition verifies the design principles. Ce3+-doped LaSi2N3O is a highly efficient blue phosphor with peak emission at 450 nm under 390 nm excitation and a quantum yield of 72.0% and demonstrates strong potential for near-UV phosphor applications.

Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) are versatile solid-state light sources whose performance is largely governed by the properties of the NIR phosphors. Herein, we report a series of Cr3+/Ni2+-co-doped CaLu2(Mg1-xZnx)2Ge3O12 (CL(M1-xZx)2GO) garnet-type solid solution near-infrared phosphors. At the optimal Zn2+ content (x = 0.8), the CL(M1-xZx)2GO:Ni2+ phosphor exhibits a threefold enhancement in emission intensity, accompanied by an increase in internal quantum efficiency from 56.9% to 86.2%. With Cr3+ co-doping, efficient Cr3+ -> Ni2+ energy transfer (up to 75%) shifts the main excitation band from 410 to 460 nm and produces continuous 600-1800 nm emission covering the NIR-I and NIR-II windows. A prototype NIR pc-LED fabricated by combining the optimized phosphor with a commercial 450 nm blue LED chip demonstrated strong potential for applications in information encryption, defect inspection, and optical wireless communication. This work offers an effective strategy for designing high-performance, ultra-broadband NIR-emitting phosphors through local structural engineering and Cr3+ -> Ni2+ sensitization.

A novel oxonitridosilicate, Li2La8Si6N12O7 was successfully synthesized at 1200 °C using Li3N as a flux. The crystal structure was determined through single-crystal and synchrotron powder X-ray diffraction. Li2La8Si6N12O7 crystallizes in orthorhombic space group Pcca (no. 54) with unit-cell parameters a = 15.5319(1) Å, b = 7.7382(1) Å, c = 15.5019(1) Å, and Z = 4. The structure features a layered framework built from vertex-sharing Si[N/O]4 tetrahedra, with Li[N/O]6 octahedra connecting and stabilizing both the interlayer and intralayer linkages. The octahedral coordination of Li+ was confirmed by solid-state 7Li NMR spectroscopy. Notably, the incorporation of Pr3+ and Tb3+ into the Li2La8Si6N12O7 host yields narrow-band red emission at 630 nm and green emission at 545 nm. This combination facilitates the fabrication of 365 nm near-ultraviolet light-emitting diode (UV LED) chip-based WLEDs with superior color rendering performance.

Silicates exhibit remarkable structure plasticity, but their complex aperiodic states are often thermally restricted. In this work, we synthesized a nitrogen-doped Eu2SiO4 phase. Multimodal structure analysis reveals that nitrogen incorporation stabilizes an incommensurately modulated structure at ambient conditions (q = 0.284(3)a *). Nitrogen preferentially occupies one of the oxygen sites, adjusting local bond valence requirements and bond length distribution. This triggers distortions in [SiO3.89N0.11] tetrahedra that accommodate internal strain. Consequently, doping stabilizes the modulated structure previously observed only at high temperature in undoped Eu2SiO4. Crucially, the anion-induced polar displacements generate an observable second-harmonic generation response and pronounced birefringence. This structural transformation demonstrates that subtle anion engineering is a potent strategy for stabilizing complex aperiodic structures and provides a new route for designing mixed-anion functional materials.

In this research work the nanoparticles (NPs) of pure and Cr-doped CrxNi(1-x)O (x = 0.01 and 0.03) were synthesized, from Ni(NO3)20.6 H2O by dropwise addition of (0.1 M) sodium hydroxide (NaOH) with constant stirring for 1 hour. Precipitate were generated which were centrifuged for 15 minutes at 5000 rpm, dried, calcinated and grinded into nano-powder. The FCC crystal structure and crystallite size varies from 19.83–23.5 nm and was examined by using XRD analysis. The Cauliflower-petal surface morphology of NiO NPs was changed into spherical and elliptical shapes and was identified by SEM analysis. The EDX and FT-IR analysis were carried out for the actual ratios of Ni, Cr and O and presence of functional groups and vibrational frequencies of bonds in CrxNi(1-x)O NPs respectively. VSM analysis shows weak ferromagnetism in pure NiO due to surface defects, with Ms = 5.03 emu·g−1 and Hc = 160 Oe. Cr-doping enhances magnetization, with the highest value of Ms = 5.71 emu·g−1 f or Cr0.01Ni0.99O, but higher doping reduces it due to spin frustration. Increasing Cr-content lowers Mr and Hc, weakening magnetic ordering. (I-V) analysis reveals ohmic behavior in pure NiO, which diminishes with Cr-doping, leading to higher conductivity and improved electrical properties. The Seebeck coefficient confirms p-type behavior (390 µV·K−1 at 300 K). Cr-doping slightly enhances thermoelectric properties, but at 600 K, bipolar conduction reduces the Seebeck coefficient.

Mixed-anion defect engineering is an effective strategy for tuning local structures and ion transport in complex oxides. Herein, we report the Li3N-assisted synthesis of the oxynitride La24Li23Ti5O53N3 (LLTON) and clarify the role of O/N incorporation in defect reconstruction and Li-ion migration. Structure analyses reveal that nitrogen preferentially substitutes apical oxygen sites in Li/Ti octahedra, inducing Li-site redistribution and oxygen-vacancy formation. These coupled defects reconstruct the local coordination environment and disrupt the ordered defect arrangement of the parent oxide while retaining the tetragonal framework. Variable-temperature diffraction further reveals a thermally driven structural evolution involving Li-site reorganization, enhanced positional disorder in the fluorite-related lithium sublattice, and a halving of the crystallographic repeat along the c direction. Ab initio molecular dynamics (AIMD) and bond valence site energy (BVSE) calculations show that these defect-induced and thermally activated rearrangements lower the Li-ion migration barrier and promote preferential one-dimensional migration along the c direction. Consequently, LLTON delivers an ionic conductivity of 3.78 mS cm-1 at 400 °C, with the activation energy reduced from 0.88 to 0.67 eV. This work establishes a structure-defect-evolution-transport correlation in mixed-anion oxides and highlights O/N defect engineering as a useful approach for regulating ion migration in complex oxide materials.

Silicates exhibit remarkable structure plasticity, but their complex aperiodic states are often thermally restricted. In this work, we synthesized a nitrogen-doped Eu2SiO4 phase. Multimodal structure analysis reveals that nitrogen incorporation stabilizes an incommensurately modulated structure at ambient conditions ( q = 0.284(3)a *). Nitrogen preferentially occupies one of the oxygen sites, adjusting local bond valence requirements and bond length distribution. This triggers distortions in [SiO3.89N0.11] tetrahedra that accommodate internal strain. Consequently, doping stabilizes the modulated structure previously observed only at high temperature in undoped Eu2SiO4. Crucially, the anion-induced polar displacements generate an observable second-harmonic generation response and pronounced birefringence. This structural transformation demonstrates that subtle anion engineering is a potent strategy for stabilizing complex aperiodic structures and provides a new route for designing mixed-anion functional materials.

In this study, we synthesized the first CAN (cancrinite)-typed zeolite-like oxonitridosilicates, Ln5Ca9O2(SiNO3)[Si12N24] (Ln = La and Ce). The crystal structure of La5Ca9O2(SiNO3)[Si12N24] was determined through single-crystal X-ray diffraction (SCXRD) data and neutron powder diffraction (NPD) data refinement. The compound crystallizes in hexagonal space group P63mc (No. 186) with a = 12.9875(2) Å, c = 5.2072(1) Å, and Z = 1. The anionic framework of La5Ca9O2(SiNO3)[Si12N24] is entirely constructed from [SiN4] tetrahedra, forming larger-sized composite building units, t-can and t-ato. The Ca2+ cations in the t-can cage contribute to balancing the charge difference originating from N3- substitution for O2- in La5Ca9O2(SiNO3)[Si12N24], which was revealed by the charge density difference calculation. The Ce3+-doped La5Ca9O2(SiNO3)[Si12N24] shows a broad-band orange-red emission peaking at λ = 630 nm under UV light excitation.

Transition metal oxynitrides, with their unique electronic structures and excellent conductivity, hold significant promise as anode materials in fuel cells. In this study, we synthesized and characterized two novel anion-deficient transition metal oxynitrides: Ca4La8V4O8N12 and Sr3La9V4O7N13. Their crystal structures were determined via Rietveld refinement of X-ray and neutron diffraction data, revealing a higher concentration of anion vacancies in Sr3La9V4O7N13. As a result, Sr3La9V4O7N13 exhibits significantly enhanced electrical conductivity compared to Ca4La8V4O8N12. Density functional theory (DFT) calculations indicate that Sr3La9V4O7N13 possesses higher defect formation energies, influencing its band structure and facilitating electron transitions, thereby enhancing conductivity. This study underscores the role of anion deficiencies in modulating the electronic properties of transition metal oxynitrides and offers new insights for designing high-performance anode materials for solid oxide fuel cells (SOFCs).

The integration of tetracycline (TC) detection and treatment within a single system is significant but challenging. This work presents a 3D Eu-based metal-organic framework (Eu-MOF) and its AgI@Eu-MOF composite, both of which serve as fluorescence turn-off sensors for monitoring TC, exhibiting high sensitivities with limits of detection (LODs) of 74.9 nmol·L-1 (nM) and 0.117 μM, respectively. The TC concentration (CTC) can be quantitatively determined using the linear fitting equations (I0 - I)/I = 3.828 × 104CTC for Eu-MOF with CTC = 9.9-90.9 μM and (I0 - I)/I = 2.1576 × 104CTC for AgI-30@Eu-MOF with CTC = 9.9-74.1 μM. The fluorescence assays using Eu-MOF and AgI@Eu-MOF were applied to lake water and tap water, whose measured CTCs were very close to the spiked CTCs, and the fluorescence recoveries were around 100%, supporting the accuracy and reliability. AgI@Eu-MOF loading 30 wt % AgI (AgI-30@Eu-MOF) was also a photocatalyst for TC photodegradation with a removal efficiency of up to 83.87%, a photocatalytic reaction rate of 0.0466 min-1, and a stable recyclability in five cycles. The TC photocatalytic degradation of AgI-30@Eu-MOF was proposed as a Z-type heterojunction mechanism with the generation of •O2-, h+, and •OH free radicals. The AgI@Eu-MOF provides a solution for TC detection and treatment by integrating a fluorescence sensor and photocatalyst within a single system.

p-Nitrophenol (p-NP) is one of the toxic nitrophenol pollutants; detection methods for these pollutants are of importance. A new europium metal-organic framework (Eu-MOF) was prepared with 5-(4H-1,2,4-triazol-4-yl)isophthalic acid (H2TIPA) and 2-aminoterephthalic acid (H2NBDC). The XPS and TEM analyses support the distribution of Pd nanoparticles (Pd NPs) on the surface of Eu-MOF with a particle size of 5.7 +/- 1.8 nm. MeOH solutions of Na+, K+, Mg2+, Ca2+, Fe3+, Mn2+, Cl-, and SO42- do not greatly affect the fluorescence quenching of Eu-MOF by p-NP. The sensitivity test shows a linear fitting equation of (I0 - I)/I = 2.45 x 105Cp-NP (Cp-NP = p-NP concentration) at Cp-NP = 1-10 with LOD = 80.1 nM. The detection mechanism is the inner filter effect based on a pseudo-first-order physical adsorption and a Freundlich model for the adsorption of p-NP by Eu-MOF and Pd@Eu-MOF@SA. The changes in the absorbance at 400 nm and the emission intensity at 450 nm occur synchronously with Cp-NP in the catalytic process of the reduction p-NP by Pd@Eu-MOF@SA. Pd@Eu-MOF@SA maintains high durability over eight adsorption-desorption cycles. Pd@Eu-MOF@SA acts as a fluorescent indicator for the catalytic reduction reaction of p-NP by NaBH4 with an obvious emission color change. This work provides a new fluorescence sensor for p-NP detection and visualization monitoring for the reduction reaction of NaBH4 and p-NP.

Piezoelectric ceramics serve as essential materials for electromechanical transduction; however, they face two critical limitations: the environmental toxicity associated with conventional lead-based systems and the inadequate strain performance, typically below 0.5%, observes in current lead-free alternatives. In this work, a synergistic design approach is presented to address both challenges by simultaneously modulating the room-temperature nonergodic relaxor to ergodic relaxor phase boundary and introducing engineered defect dipoles (P d) in (Bi0.5Na0.5)0.93Ba0.07TiO3 (BNBT) ceramics through B-site co-substitution with aliovalent (Sn0.5Sb0.4)4+ complex ions. This dual-modulation strategy leverages field-induced phase transitions, the morphotropic phase boundary effect, and the cooperative alignment between spontaneous polarization and defect dipole polarization. As a result, the material system exhibits markedly suppressed negative strain, a substantial internal bias field that facilitates reversible domain switching, and an exceptional electromechanical response. Specifically, an ultrahigh electrostrain of 1.06%, a giant effective piezoelectric coefficient of 1317 pm V-1, and an ultralow strain hysteresis of 7.2% are achieved. These metrics rival those of benchmark lead-based ceramics such as Pb(Zr1- xTix)O3. The proposed methodology offers a promising pathway for the development of high-performance, environmentally benign actuator materials suitable for advanced electromechanical applications.

The exploration of new luminescent materials is driven by potential applications in solid-state lighting and display technologies. In this paper, we employed an anionic condensation approach to craft novel oxonitridosilicate compounds by substituting 3O(2-) with 2N(3-) in a carefully selected system. This approach enabled us to synthesize a highly condensed oxonitridosilicate compound LaSr4Si5N9O2, which crystallizes in the orthorhombic crystal system with the space group Ama2 (no. 40) and lattice parameters a = 9.2986(1) & Aring;, b = 23.4382(1) & Aring;, c = 5.371(1) & Aring;, V = 1170.55(1) & Aring;(3), and Z = 4. The condensation appears inside the layer, with dreier rings originating from neighboring tetrahedra connected by bridging nitride (N-[2]). This enriches the possibility of using the approach to design multiple layered or other featured oxonitridosilicates. Furthermore, we investigated the luminescence properties when doped with rare-earth ions. The Pr3+-doped LaSr4Si5N9O2 exhibits a remarkably narrow-band red emission (lambda(em) approximate to 618 nm, fwhm approximate to 54 nm) when excited by UV and blue light.

Quantitative detection of tetracycline (TC) and nitrofurantoin (NFT) in food and water is of importance for food safety and environmental protection. Herein, Zn2+ was introduced into a europium metal-organic framework Eu-bpdc (H2bpdc = 2,2'-bipyridyl-5,5'-dicarboxylic acid) to prepare a composite of Zn2+@Eu-bpdc, which was developed as a fluorescence sensor for TC and NFT. The fluorescence mechanism concerns with bpdc2- ligand-to-Eu(III) charge transfer, and the detection mechanism is the inner filter effect. Zn2+@Eu-bpdc is a ratiometric fluorescence sensor for TC with the linear fitting equation of I520/I618 = 1.94 × 104 M-1CTC, whose limit of detection (LOD) is 0.148 μmol·L-1 (μM); it is also a fluorescence "turn-off" sensor for NFT with the fitting equation of (I0-I)/I = 3.62 × 104 M-1CNFT and LOD = 0.0792 μM. Zn2+@Eu-bpdc can detect TC or NFT in lake water, honey, and milk with high accuracy. The emission color changes of paper-based Zn2+@Eu-bpdc depending on CTC or CNFT reveal the visualization detections of TC and NFT. With the red and green values as input signals, smartphone-assisted on-site detection is utilized to recognize the antibiotic residuals of TC and NFT by a self-programmed APP. Zn2+@Eu-bpdc is promising in a smartphone-assisted intelligent platform for on-site detection of TC and NFT.

With the continuous development of higher education and the significant investment in talent cultivation and technological advancement by the country,the safety management and proper disposal of laboratory waste in universities have become crucial for the construction of environmentally-friendly and secure campus and the sustainable development of human society.This paper categorizes and describes the characteristics of chemical laboratory waste,and analyzes the current issues in waste management and disposal from five perspectives,extensive coverage,high personnel mobility,diverse and complex waste,insufficient safety and environmental awareness,and inadequate management.By taking into account the specific circumstances of schools,colleges,and local enterprises,a closed-loop management and disposal practice model is proposed,which integrates safety and environmental education,experimental planning,implementation of institutional regulations,and efficient information support,aiming to provide a reference for the treatment of laboratory waste.

Near-infrared (NIR) phosphor materials are increasingly being recognized for their diverse functional applications. In this study, we investigate the enhancement of NIR emission and thermal stability in La2MgSnO6:Mn4+,Ni2+ through energy transfer mechanisms. Our findings reveal that co-doping La2MgSnO6 with Mn4+ significantly enhances Ni2+ absorption in the blue light region, markedly increases the NIR emission intensity, and improves thermal quenching performance. The newly developed La2MgSnO6:Mn4+,Ni2+ phosphors, when incorporated into NIR phosphor-converted LEDs (pc-LEDs), demonstrate significant potential for applications in night vision, information encryption, and vein imaging. This research paves a new path for enhancing the luminescent properties of Ni(2+ )and advancing high-performance NIR phosphors.

Many phosphor hosts, for example, nitrides and sulfides, often face challenges such as hydrolysis and oxidation, limiting their application in phosphor-converted white light-emitting diodes (pc-LEDs). In this study, we developed a highly humidity-resistant yellow-green-emitting phosphor BaSi6N8O:Ce3+ (BSNO:Ce3+). The DFT calculations revealed a high Debye temperature (Theta D = 1159 K), indicating a rigid crystal structure that contributes to the photoluminescence thermal quenching resistance of BSNO. Furthermore, we observed a notable positional shift of Ce3+ in the BSNO lattice, contributing to an unusual photoluminescence (PL) red shift compared to BSNO:Eu2+. Importantly, BSNO:Ce3+ exhibited remarkable PL stability under harsh conditions, showing no degradation in water for 10 days and less than 10% intensity loss at elevated temperatures up to 773 K. We constructed a prototype white LED with a high color rendering index (R a = 92) by combining a 365 nm chip with BSNO:0.03Ce3+ and commercial phosphors, demonstrating its potential for advanced pc-LED applications.