Micro-nano H2 bubbles enhanced hydrodehalogenation of 3-chloro-4-fluoroaniline: Mass transfer and action mechanism.

3-chloro-4-fluoraniline (FCA) is an important intermediate for the synthesis of antibiotics, herbicides and insecticides, and has significant environmental health hazards. Catalytic hydrogenation technology is widely used in pretreatment of halogenated organics due to its simple process and excellent performance. However, compared with the research of high activity hydrogenation catalyst, the research of efficient utilization of hydrogen source under mild conditions is not sufficient. In this work, micro-nano H2 bubbles are produced in situ by electrolytic water and active metal replacement, and their apparent properties are studied. The result show that the H2 bubbles have a size distribution in the range of 150-900 nm, which can rapidly reduce the REDOX potential of the water and maintain it in a hydrogen-rich state for a long time. Under the action of Pd/C catalyst, atomic hydrogen (H•) produced by dissociative adsorption can sequentially hydrogenate FCA to aniline. The H• utilization ratios of the above two hydrogen supply pathways reach 6.20% and 4.94% respectively, and H2 consumption is reduced by tens of times (≥50 → ≈1.0 mL/min). The research provides technical support for the efficient removal of halogenated refractory pollutants in water and the development of hydrogen economy.

A Rare Earth Chalcogenide Nonlinear Optical Crystal KLaGeS4: Achieving Good Balance among Band Gap, Second Harmonic Generation Effect, and Birefringence.

Midinfrared nonlinear optical (NLO) rare earth chalcogenides have attracted extensive research interest in recent several decades. Employing charge-transfer engineering strategy in the early stage, rigid tetrahedral [GeS4] was introduced into rare-earth sulfides to synthesize KYGeS4, which had an enlarged band gap while maintaining a strong second harmonic generation (SHG) effect. Based on KYGeS4, La was equivalently substituted to successfully synthesize KLaGeS4 with a stronger SHG effect (dij = 1.2 × AgGaS2) and lower cost. Meanwhile, a larger band gap (Eg = 3.34 eV) was retained and realized phase matching (Δn = 0.098 @ 1064 nm). KLaGeS4 enabled an effective balance among band gap, SHG effect, and birefringence, making it a promising candidate for infrared NLO optical materials among various rare-earth sulfides.

Optimal Design of Mid-Infrared Nonlinear-Optical Crystals: From SrZnSnSe4 to SrZnSiSe4.

Improving the laser damage threshold (LDT) of mid-infrared nonlinear-optical (MIR NLO) crystal materials is crucial for their applications in areas such as environmental monitoring and pharmaceutical detection. This paper presents the successful synthesis of SrZnSiSe4, a new MIR NLO crystal material that balances the LDT and second-harmonic-generation (SHG) effects and achieves phase matching. By replacement of Sn with Si in the existing SrZnSnSe4 material, the band gap of the material was increased, resulting in an LDT that is twice that of SrZnSnSe4, while maintaining the 2 × AgGaS2 effect. The SHG and band gap of SrZnSiSe4 derived from the experiments are 2 × AgGaS2 and 1.95 eV. The band gap of SrZnSiSe4 is better than that of SrZnSnSe4 (1.82 eV), and the LDT of SrZnSiSe4 is about twice that of SrZnSnSe4. Moreover, first-nature principal calculations confirm that SrZnSiSe4 can achieve phase matching after 1520 nm with a birefringence of 0.10, making it an excellent candidate for MIR NLO crystals.

Electrocatalytic degradation of methyl orange and 4-nitrophenol on a Ti/TiO2-NTA/La-PbO2 electrode: electrode characterization and operating parameters.

The anode material plays a crucial role in the process of electrochemical oxidation. Herein, a TiO2 nanotube arrays (TiO2-NTA) intermediate layer and La-PbO2 catalytic layer were synthesized on a Ti surface by the electrochemical anodic oxidation and electrochemical deposition technology, respectively. The prepared Ti/TiO2-NTA/La-PbO2 electrode was used as an electrocatalytic oxidation anode for pollutant degradation. Scanning electron microscopy (SEM) analysis showed that the TiO2-NTA layer possessed a highly ordered and well-aligned nanotube array morphology, and the La-PbO2 layer with angular cone cluster was uniform and tightly bonded. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis indicated that the intermediate layer primarily consisted of the anatase crystal structure of TiO2 and the catalyst layer was made of La-PbO2. Electrochemical analysis revealed that Ti/TiO2-NTA/La-PbO2 electrode exhibited higher oxidation peak current, electrochemical active surface area, and oxygen evolution potential (OEP, 1.64 V). Using methyl orange and 4-nitrophenol as model pollutants, electrocatalytic properties of the prepared Ti/TiO2-NTA/La-PbO2 electrode were systematically investigated under different conditions, and the electrochemical degradation fitted well with the pseudo-first-order kinetics model. Efficient anodic oxidation of model pollutants was mainly attributed to the indirect oxidation mediated by hydroxyl radicals (•OH). The total organic carbon (TOC) removal efficiency of methyl orange and 4-nitrophenol was 70.2 and 72.8%, and low energy consumption (2.50 and 1.89 kWh g-1) was achieved after 240 min of electrolysis under the conditions of initial concentration of model pollutant, electrode spacing, and electrolyte concentration were 50 mg L-1, 2 cm, and 0.1 mol L-1, respectively. This work provided a new strategy to develop the high-efficiency electrode for refractory pollutants degradation.

Impact of Pyrite Oxidation on the Pore-Structure Characteristics of Shale Reservoir Rocks under the Interaction of Fracturing Fluid.

Hydraulic fracturing combined with horizontal drilling is widely used to develop shale gas resources, and huge amounts of fracturing fluid are injected into shale reservoirs. However, the fracturing fluid is ineluctably retained in reservoir rocks after fracturing, resulting in the alteration of shale pore systems and further affecting the hydrocarbons production efficiency. In this work, two types of shales with different pyrite contents, namely, pyrite rich (PR, Niutitang Formation) and pyrite poor (PP, Xiamaling Formation), were emphasized to illustrate the effect of pyrite oxidation on pore structure after fracturing operation. Slickwater fracturing fluid was used to treat the shale samples for a period of 3 days, under the condition of 100 °C and 50 MPa. The field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) were utilized to determine the surface morphology and mineral composition. The low-temperature N2 adsorption was performed to quantify the pore structure. The results showed that the pyrite oxidation induced the dissolution of both the pyrite and calcite and generated many dissolution pores for the pyrite-rich shale after slickwater treatment. The mineral dissolution led to an increase in the number of mesopores, enlarged the total specific surface area (TSSA) and total pore volume (TPV), and strengthened the pore-structure complexity. On the other hand, the pyrite-poor shale only experienced clay swelling after slickwater treatment. Its pore surface roughness and pore-structure complexity degraded with the loss of nanopores and the reductions in TSSA and TPV. The results of this study enhance the understanding of the impact of pyrite oxidation on the pore structure and provide new insight into the optimization of fracturing operation conditions based on shale's mineral composition characteristics.

A Research on Delayed Thermal Depolarization, Electric Properties, and Stress in (Bi0.5Na0.5)TiO3-Based Ceramic Composites.

Depolarization behavior is one of the main shortcomings of (Bi0.5Na0.5)TiO3-based ceramics. Considering the undesirable efficiency of traditional modification methods, in this paper a series of 0-3 type ceramic composites 0.85(Bi0.5Na0.5)TiO3-0.11(Bi0.5K0.5)TiO3-0.04BaTiO3-x mol% ZnO (BNKT-BT-xZnO)) were synthesized by introducing ZnO nanoparticles. The results of the X-ray diffraction pattern (XRD) and energy dispersive spectroscopy (EDS) demonstrate that the majority of ZnO nanoparticles grow together to form enrichment regions, and the other Zn2+ ions diffuse into the matrix after sintering. With ZnO incorporated, the ferroelectric-ergodic relaxor transition temperature, TF-R, and depolarization temperature, Td, increase to above 120 °C and 110 °C, respectively. The research on temperature-dependent P-E loops verifies an attenuated ergodic degree induced by ZnO incorporation. For this reason, piezoelectric properties can be well-maintained below 110 °C. The electron backscatter diffraction (EBSD) was employed to investigate the stress effect. Orientation maps reveal the random orientation of all grains, excluding the impact of texture on depolarization. The local misorientation image shows that more pronounced strain appears near the boundaries, implying stress is more concentrated there. This phenomenon supports the hypothesis that potential stress suppresses depolarization. These results demonstrate that the depolarization behavior is significantly improved by the introduction of ZnO. The composites BNKT-BT-xZnO are promising candidates of lead-free ceramics for practical application in the future.

Degradation of Minocycline by the Adsorption-Catalysis Multifunctional PVDF-PVP-TiO2 Membrane: Degradation Kinetics, Photocatalytic Efficiency, and Toxicity of Products.

The photocatalytic degradation of minocycline was studied by using polyvinylidene fluoride-polyvinylpyrrolidone-TiO2 (PVDF-PVP-TiO2) fiber mats prepared by an electrospinning technology. The influences of the TiO2 dosage, minocycline concentrations, inorganic anions, pH values, and dissolved organic matter (DOM) concentrations on the degradation kinetics were investigated. A mass of 97% minocycline was degraded in 45 min at 5% TiO2 dosage. The corresponding decomposition rate constant was 0.069 min-1. The inorganic anions affected the minocycline decomposition in the order of HCO3- > Cl- > SO42- > NO3-, which was confirmed by the results of electron spin resonance (ESR) spectra. The lowest electrical energy per order (EEO) was 6.5 Wh/L. Over five cycles, there was no change in the photocatalytic performance of the degrading minocycline. Those investigations suggested that effective degradation of minocycline could be reached in the PVDF-PVP-TiO2 fiber mats with a low energy consumption, good separation and, good recovery. Three photocatalytic decomposition pathways of minocycline were proposed: (i) hydroxyl substitution of the acylamino group; (ii) hydroxyl substitution of the amide group, and (iii) a cleavage of the methyl groups and further oxidation of the amino group by OH. Potential risks caused by TP159 and TP99 should not be ignored, while the TP90 are nontoxic. Tests indicated that the toxicity of the photocatalytic process may be persistent if minocycline and its products were not mineralized completely.

Breaking through the "3.0 eV wall" of energy band gap in mid-infrared nonlinear optical rare earth chalcogenides by charge-transfer engineering.

Increasing the energy band gap under the premise to maintain a large nonlinear optical (NLO) response is a challenging issue for the exploration and molecular design of mid-infrared nonlinear optical crystals. Utilizing a charge-transfer engineering method, we designed and synthesized a rare earth chalcogenide, KYGeS4. With an NLO effect as large as that in AgGaS2, KYGeS4 breaks through the limitation of energy band gap, i.e., the "3.0 eV wall", in NLO rare earth chalcogenides, and thus exhibits an excellent comprehensive NLO performance. First-principles electronic structure analysis demonstrates that the large band gap in KYGeS4 is ascribed to the decreased covalency of Y-S bonds by transferring charge from [YS7] to [GeS4] polyhedra. The charge-transfer engineering strategy would have significant implications for the exploration of good-performance NLO crystals.

Multifunctional, Robust, and Porous PHBV-GO/MXene Composite Membranes with Good Hydrophilicity, Antibacterial Activity, and Platelet Adsorption Performance.

The limitations of hydrophilicity, strength, antibacterial activity adsorption performance of the biobased and biocompatible polymer materials, such as polyhydroxyalkanoates (PHAs), significantly restrict their wider applications especially in medical areas. In this paper, a novel composite membrane with high antibacterial activity and platelet adsorption performance was prepared based on graphene oxide (GO), MXene and 3-hydroxybutyrate-co-hydroxyvalerate (PHBV), which are medium-chain-length-copolymers of PHA. The GO/MXene nanosheets can uniformly inset on the surface of PHBV fibre and give the PHBV-GO/MXene composite membranes superior hydrophilicity due to the presence of hydroxyl groups and terminal oxygen on the surface of nanosheets, which further provides the functional site for the free radical polymerization of ester bonds between GO/MXene and PHBV. As a result, the tensile strength, platelet adsorption, and blood coagulation time of the PHBV-GO/MXene composite membranes were remarkably increased compared with those of the pure PHBV membranes. The antibacterial rate of the PHBV-GO/MXene composite membranes against gram-positive and gram-negative bacteria can reach 97% due to the antibacterial nature of MXene. The improved strength, hydrophilicity, antibacterial activity and platelet adsorption performance suggest that PHBV-GO/MXene composite membranes might be ideal candidates for multifunctional materials for haemostatic applications.

Improved Non-Piezoelectric Electric Properties Based on La Modulated Ferroelectric-Ergodic Relaxor Transition in (Bi0.5Na0.5)TiO3-Ba(Ti, Zr)O3 Ceramics.

The characteristic transition from ferroelectric (FE) to ergodic relaxor (ER) state in (Bi0.5Na0.5)TiO3 (BNT) based lead-free ceramics provides an efficient approach to bring a highly ordered phase back to a disordered one. It would be rational to utilize this transition to improve relevant non-piezoelectric properties based on domain decomposition. In this work, different La contents were introduced to 0.93(Bi0.5Na0.5)TiO3-0.07Ba(Ti0.945Zr0.055)O3 ceramics (BNT-BZT-xLa) to induce evolution of ergodic degree. The results reveal that with increasing La content, both the FE-ER transition temperature TF-R and depolarization temperature Td shift towards room temperature, implying a deepened ergodic degree. By modulation of ergodic degree, thermally stimulated depolarization current experiment shows a higher current density peak, and corresponding pyroelectric coefficient increases from 2.46 to 2.81 µC/(cm2∙°C) at Td. For refrigeration, the indirect measurement demonstrates the ΔT maximum increases from 1.1 K to 1.4 K, indicating an enhanced electrocaloric effect. Moreover, the optimized energy storage effect is observed after La doping. With appearance of "slimmer" P-E loops, both calculated recoverable energy storage density Wrec and storage efficiency η increase to 0.23 J/cm3 and 22.8%, respectively. These results denote La doping conduces to the improvement of non-piezoelectric properties of BNT-based ceramics in a certain range. Therefore, La doping should be an adopted modification strategy for lead-free ceramics used in areas like refrigerator and pulse capacitors.

Chemical characterization of particulate organic matter from commercial restaurants: Alkyl PAHs as new tracers for cooking.

Cooking is one of the primary sources of particulate organic matter (POM) in urban environments. Numerous experiments have been performed to investigate the composition of POM generated during cooking. However, there still remain substantial uncertainties in our knowledge regarding the emission characteristics of alkyl polycyclic aromatic hydrocarbons (PAHs) from cooking. In addition, previous studies have selected several tracers for Chinese cooking; however, these results were acquired based on observations in the Pearl River Delta region of China, and only four of the eight Chinese cooking styles were tested. Therefore, the organic compositions of the PM2.5 emitted from four Chinese cooking restaurants in different cities are examined to investigate the emission characteristics of alkyl PAH and to verify whether the selected tracers vary with geographical location and cooking styles. In this study, C1- and C2-phenanthrenes/anthracenes, and C1-pyrenes were detected in the PM2.5 from the four tested restaurants, but the concentrations of these PAH alkyl homologues were all at low levels, and also much lower than the corresponding parent PAHs. However, the distribution pattern of the alkyl PAHs in the cooking fumes was significantly different from that in the PM from other emission sources. Additionally, some candidate tracers for cooking such as levoglucosan were less influenced by cooking styles or geographical location. Thus, these alkyl PAHs in conjunction with other specific tracers for cooking were utilized to estimate the contribution of cooking to ambient organic carbon. The results showed that the estimates from the chemical mass balance model that includes alkyl PAHs will be higher than the model that does not, and in the case of high alkyl PAHs ambient concentrations, the model that includes alkyl PAHs will provide more reasonable results.

The role of carbonate in sulfamethoxazole degradation by peroxymonosulfate without catalyst and the generation of carbonate racial.

Peroxymonosulfate (PMS) can be activated by various catalysts to degrade organic contaminants in wastewater treatment processes. In this research, the co-activation of PMS by sulfamethoxazole (SMX) and carbonate is investigated. The results show that SMX can be degraded in situ, and the main reactive oxygen species are singlet oxygen and carbonate radicals. Only singlet oxygen is detected when SMX is degraded by PMS without carbonate. However, both carbonate radicals and hydroxyl radicals are measured in the presence of carbonate. Among which, hydroxyl radicals are identified by electron paramagnetic resonance spectroscopy method, and carbonate radicals are confirmed by radical quenching experiments, as well as the variation of SMX degradation kinetic and the appreance of carbonyldioxy derivatives by-products in the presence of carbonate anions. Based on this phenomenon, it is proposed that carbonate can enhance the decomposition of PMS and the generation of secondary free radicals (carbonate radicals). Thus carbonate radicals can enhance the oxidizability for sulfonamide antibiotics in the PMS-based advanced oxidation systems. These results suggest that the addition of carbonate is an important enhancement method for the treatment of sulfonamide antibiotics in water.

From CuFeS2 to Ba6Cu2FeGe4S16: rational band gap engineering achieves large second-harmonic-generation together with high laser damage threshold.

A new germanium-based sulfide, Ba6Cu2FeGe4S16, achieves a band-gap broadening of more than 1 eV relative to CuFeS2. Remarkably, Ba6Cu2FeGe4S16 exhibits excellent comprehensive NLO performance (SHG, 1.5 × AgGaSe2; LDT, 2 × AgGaSe2), satisfying the essential requirements of mid-IR NLO candidates.

Rb10Zn4Sn4S17: A Chalcogenide with Large Laser Damage Threshold Improved from the Mn-Based Analogue.

In the military and civilian fields, with the development of new technologies, high-powered nonlinear optical (NLO) crystals demonstrate broad application prospects. In this work, for purposes of designing a better NLO material, a new chalcogenide Rb10Zn4Sn4S17 was successfully designed with a high temperature solid-state method on the basis of previously reported compound Sr3MnSn2S8. The experimental results indicate that Rb10Zn4Sn4S17 possesses a prominent band gap of 3.59 eV, compared with the laser damage threshold (LDT) of Sr3MnSn2S8 (3 times that of AgGaS2); Rb10Zn4Sn4S17 shows an outstanding LDT about 5 times that of AgGaS2. Meanwhile, it has an ideal second harmonic generation (SHG) response approximately 0.7 times that of AgGaS2.

Regeneration of porous electrospun membranes embedding alumina nanoparticles saturated with minocycline by UV radiation.

A regeneration method for porous electrospun membranes embedding alumina nanoparticles saturated with minocycline was investigated by UV-LED system. The percentage of adsorption capacities before and after regeneration were used to evaluate regeneration efficiency. The PVDF and PVDF-Al2O3 fiber mats were prepared by electrospinning technique. Scanning electron microscope (SEM), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS) analyses directly confirmed that Al2O3 nanoparticles were generally exposed to the surface of PVDF-Al2O3 fiber mats. Among them, PVDF-Al2O3 10% fiber mats can effectively adsorb minocycline (remove efficiency >97% in 18 h) with first-order rate constant k = 2.253 ±â€¯0.331 h-1. The sorption capacity can still keep 81% after five sorption/UV-regeneration circulations. Two successional stages may exist during regeneration: (i) transfer of minocycline from the surface of PVDF-Al2O3 fibers to the DI water, followed by the (ii) decomposition of this compound in aqueous solution by direct and indirect photolysis to yield the intermediate species. The desorption capacity and desorption percentage were 4.39 mg g-1 and 23.30% respectively. The regeneration yields were further enhanced to 94.20% by UV radiation. Minocycline was effectively degraded to intermediate products by direct and indirect photolysis, further degraded into CO2, H2O, and NOx by UV-generated ozone during regeneration. The results indicated that UV radiation was an effective method of regenerating PVDF-Al2O3 fiber mats with low energy requirements. The photochemical byproducts and the reaction sites during regeneration were also determined and recognized.

LiGaGe2S6: A Chalcogenide with Good Infrared Nonlinear Optical Performance and Low Melting Point.

In this work, we design and synthesize a new chalcogenide LiGaGe2S6 on the basis of known infrared (IR) material LiGaS2 by partially substituting Ga with Ge. This compound possesses very strong nonlinear (NLO) response (2.5 × LiGaS2) and large band gap (3.52 eV), manifesting a better balance between band gap and NLO response compared with that for LiGaS2. Moreover, LiGaGe2S6 exhibits a much lower melting point (663 °C) than that of LiGaS2 (1050 °C). This would result in the much smaller vapor pressure of sulfur in the fused quartz vessels used for the crystal growth, and thus, it should be greatly beneficial to obtain the large stoichiometric LiGaGe2S6 single crystal. Our studies demonstrate that LiGaGe2S6 is a good candidate material for IR NLO applications.

Bio-Electron-Fenton (BEF) process driven by microbial fuel cells for triphenyltin chloride (TPTC) degradation.

The intensive use of triphenyltin chloride (TPTC) has caused serious environmental pollution. In this study, an effective method for TPTC degradation was proposed based on the Bio-Electron-Fenton process in microbial fuel cells (MFCs). The maximum voltage of the MFC with graphite felt as electrode was 278.47% higher than that of carbon cloth. The electricity generated by MFC can be used for in situ generation of H2O2 to a maximum of 135.96µmolL-1 at the Fe@Fe2O3(*)/graphite felt composite cathode, which further reacted with leached Fe2+ to produce hydroxyl radicals. While 100µmolL-1 TPTC was added to the cathodic chamber, the degradation efficiency of TPTC reached 78.32±2.07%, with a rate of 0.775±0.021µmolL-1h-1. This Bio-Electron-Fenton driving TPTC degradation might involve in SnC bonds breaking and the main process is probably a stepwise dephenylation until the formation of inorganic tin and CO2. This study provides an energy saving and efficient approach for TPTC degradation.

Genome sequence of a microbial lipid producing fungus Cryptococcus albidus NT2002.

Cryptococcus albidus NT2002, isolated from the soil in Xinjiang, China, appeared to have the ability to accumulate microbial lipid by utilizing various carbon sources. The predominant properties make it as a potential bio-platform for biodiesel production. Here, we report the complete genome sequence of C. albidus NT2002, which might provide a basis for further elucidation of the genetic background of this promising strain for developing metabolic engineering strategies to produce biodiesel in a green and sustainable manner.

K2Ln2As2Se9 (Ln = Sm, Gd): the first quaternary rare-earth selenoarsenate compounds with a 3D framework containing chairlike As2Se4 units.

The new compounds K(2)Ln(2)As(2)Se(9) (Ln = Sm, Gd) were obtained by applying the reactive flux method. The structure consists of a three-dimensional (3D) [Ln(2)As(2)Se(9)](2-) framework with K(+) ion-filling tunnels running along the b axis. The two unique Ln(3+) cations are coordinated by two Se(2)(2-) dumbbells, two AsSe(3)(3-) pyramids, and one chairlike As(2)Se(4)(2-) unit in a bicapped trigonal-prismatic geometry. The Ln(3+)-centered trigonal prisms share triangular faces with neighboring prisms, forming one-dimensional chains along the b axis. These chains are linked to each other to form layers by sharing Se(2-) anions on the capped sites of the trigonal prisms. The As(2)Se(4) units connect these layers to form the 3D framework.

Syntheses, structures, and spectroscopic properties of K9Nd[PS4]4, K3Nd[PS4]2, Cs3Nd[PS4]2, and K3Nd3[PS4]4.

Four new quaternary alkali neodymium thiophosphates K 9Nd[PS 4] 4 ( 1), K 3Nd[PS 4] 2 ( 2), Cs 3Nd[PS 4] 2 ( 3), and K 3Nd 3[PS 4] 4 ( 4) were synthesized by reacting Nd with in situ formed fluxes of K 2S 3 or Cs 2S 3, P 2S 5 and S in appropriate molar ratios at 973 K. Their crystal structures are determined by single crystal X-ray diffraction. Crystal data: 1: space group C2/ c, a = 20.1894(16), b = 9.7679(5), c = 17.4930(15) A, beta = 115.66(1) degrees , and Z = 4; 2: space group P2 1/ c, a = 9.1799(7), b = 16.8797(12), c = 9.4828(7) A, beta = 90.20(1) degrees , and Z = 4; 3: space group P2 1/ n, a = 15.3641(13), b = 6.8865(4), c = 15.3902(13) A, beta = 99.19(1) degrees , and Z = 4; 4: space group C2/ c, a = 16.1496(14), b = 11.6357(7), c = 14.6784(11) A, beta = 90.40(1) degrees , and Z = 4. The structure of 1 is composed of one-dimensional (1) infinity{Nd[PS 4] 4} (9-) chains and charge balancing K (+) ions. Within the chains, eight-coordinated Nd (3+) ions, which are mixed with K (+) ions, are connected by [PS 4] (3-) tetrahedra. The crystal structures of 2 and 3 are characterized by anionic chains (1) infinity{Nd[PS 4] 2} (3-) being separated by K (+) or Cs (+) ions. Along each chain the Nd (3+) ions are bridged by [PS 4] (3-) anions. The difference between the structures of 2 and 3 is that in 2 the Nd (3+) ions are coordinated by four edge-sharing [PS 4] (3-) tetrahedra while in 3 each Nd (3+) ion is surrounded by one corner-sharing, one face-sharing, and two edge-sharing [PS 4] (3-) tetrahedra. The structure of 4 is a three-dimensional network with K (+) cations residing in tunnels running along [110] and [110]. The {Nd(1)S 8} polyhedra share common edges with four [PS 4] tetrahedra forming one-dimensional chains (1) infinity{Nd[PS 4] 2} (3-) running along [110] and [110]. The chains are linked by {Nd(2)S 8} polyhedra yielding the final three-dimensional network (3) infinity{Nd[PS 4] 2} (3-). The internal vibrations of both crystallographically independent [PS 4] (3-) anions of 2- 4 have been assigned in the range 200-650 cm (-1) by comparison of their corresponding far/mid infrared and Raman spectra (lambda exc = 488 nm) on account of locally imposed C 1 symmetry. In the Fourier-transform-Raman spectrum (lambda exc = 1064 nm) of 2- 4, very similar well-resolved electronic Raman (ER) transitions from the electronic Nd (3+) ground-state to two levels of the (4)I 9/2 ground manifold and to the six levels of the (4)I 11/2 manifold have been determined. Resonant Raman excitation via a B-term mechanism involving the (4)I 15/2 and (4)F 3/2 intermediate states may account for the significant intensity enhancement of the ER transitions with respect to the symmetric P-S stretching vibration nu 1. Broad absorptions in the UV/vis/NIR diffuse reflectance spectrum at 293 K in the range 5000-25000 cm (-1) of 2- 4 are attributed to spin-allowed excited quartet states [ (4)(I < F < S < G < D)] and spin-forbidden doublet states [ (2)(H < G < K < D < P)] of Nd (3+). A luminescense spectrum of 3 obtained at 15 K by excitation with 454.5 nm shows multiplets of narrow lines that reproduce the Nd (3+) absorptions. Sharp and intense luminescence lines are produced instead by excitation with 514.5 nm. Lines at 18681 ( (4)G 7/2), 16692 ( (4)G 5/2), 14489 ( (4)F 9/2), and 13186 cm (-1) ( (4)F 7/2) coincide with the corresponding absorptions. Hypersensitive (4)G 5/2 is split by 42 cm (-1). The most intense multiplet at about 16500 cm (-1) is assigned to the transition from (4)G 5/2 to the Stark levels of the ground manifold (4)I 9/2.