Construction of novel photocatalysts for efficient hydrogen evolution: The key role of natural halloysite nanotubes.

Hydrogen (H2) evolution by photocatalytic water splitting is a potential strategy to solve worldwide energy shortage. Sulfide nanocatalysts showed great potential for H2 evolution, but suffered from low charge separation efficiency and easy agglomeration. In this work, ZnIn2S4 (ZIS) nanoflowers were anchored onto the surface of halloysite nanotubes (HNTs) modified by ethylenediaminetetraacetic acid (EDTA). Photocatalyst 3ZnIn2S4-HNTs/EDTA3 (3ZIS-HNTs/E3) displayed the optimum H2 evolution rate of 10.4 mmol·g-1·h-1, being 3.4 times as that of the original ZIS. Moreover, 3ZIS-HNTs/E3 presented satisfied property in the photocatalytic hydrogenation reaction of 4-nitrophenol to produce 4-aminophenol. HNTs as substrates not only hindered the growth and agglomeration of ZIS, but also induced more S vacancies in ZIS. The production of Schottky junctions between ZIS and Pt, the high utilization of light energy in tubular HNTs, and the trapping effect of EDTA for photogenerated h+ were all favorable for enhancing the catalytic property. The density functional theory (DFT) calculations showed that 3ZIS-HNTs/E3 with more S vacancies had the lowest adsorption energy and the most appropriate ΔGH* for H* to enhance the H2 evolution efficiency, which was consistent with the experimental catalytic results. This study contributes a novel thought for synthesizing composites on the basis of natural minerals for taking part in and enhancing the catalytic performance.

Toward the Long-Term Stability of Cobalt Benzoate Confined Highly Dispersed PtCo Alloy Supported on a Nitrogen-Doped Carbon Nanosheet/Fe3C Nanoparticle Hybrid as a Multifunctional Catalyst for Zinc-Air Batteries.

This work reports a new type of platinum-based heterostructural electrode catalyst that highly dispersed PtCo alloy nanoparticles (NPs) confined in cobalt benzoate (Co-BA) nanowires are supported on a nitrogen-doped ultra-thin carbon nanosheet/Fe3C hybrid (PtCo@Co-BA-Fe3C/NC) to show high electrochemical activity and long-term stability. One-dimensional Co-BA nanowires could alleviate the shedding and agglomeration of PtCo alloy NPs during the reaction so as to achieve satisfactory long-term durability. Moreover, the synergistic effect at the interface optimizes the surface electronic structure and prominently accelerates the electrochemical kinetics. The oxygen reduction reaction half-wave potential is 0.923 V, and the oxygen evolution reaction under the condition of 10 mA•cm-2 is 1.48 V. Higher power density (263.12 mW•cm-2), narrowed voltage gap (0.49 V), and specific capacity (808.5 mAh•g-1) for PtCo@Co-BA-Fe3C/NC in Zn-air batteries are achieved with long-term cycling measurements over 776 h, which is obviously better than the Pt/C + RuO2 catalyst. The interfacial electronic interaction of PtCo@Co-BA-Fe3C/NC is investigated, which can accelerate electron transfer from Fe to Pt. Density functional theory calculations also indicate that the interfacial potential regulates the binding energies of the intermediates to achieve the best performance.

Adsorbent biochar derived from corn stalk core for highly efficient removal of bisphenol A.

Environmental-friendly biochar (BC) with low cost was obtained by simple pyrolysis of corn stalk core, which was employed as an adsorbent for efficiently removing organic pollutants in water. The physicochemical properties of BCs were characterized by various techniques, including X-ray diffractometer (XRD), Fourier transforms infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectrometer (XPS), Raman, Thermogravimetric (TGA), N2 adsorption-desorption and zeta potential tests. The influence of pyrolysis temperature on the structure and adsorption efficiency of the adsorbent was emphasized. The graphitization degree and sp2 carbon content of BCs were enhanced by increasing the pyrolysis temperature, which was favorable for the enhancement of the adsorption efficiency. The adsorption results showed that corn stalk core calcined at 900 °C (BC-900) displayed exceptional adsorption efficiency toward bisphenol A (BPA) in wide pH (1-13) and temperature (0-90 °C) ranges. Moreover, adsorbent BC-900 could adsorb various pollutants from water, including antibiotics, organic dyes, and phenol (50 mg·L-1). The adsorption process of BPA over BC-900 matched well with the Langmuir isotherm and pseudo-second-order kinetic model. Mechanism investigation suggested that large specific surface area and pore filling acted the foremost role in the adsorption process. Adsorbent BC-900 has the potential application in wastewater treatment due to its simple preparation, low cost, and excellent adsorption efficiency.

Photoelectrocatalytic peroxymonosulfate activation over CoFe2O4-BiVO4 photoanode for environmental purification: Unveiling of multi-active sites, interfacial engineering and degradation pathways.

This work reported on the development of CoFe2O4-BiVO4 photoanode based photoelectrocatalytic system collaborating with peroxymonosulfate activation for organic contaminants removal. CoFe2O4 layer not only provided active sites for direct peroxymonosulfate activation but also accelerated charge separation process for the enhancement of photocurrent density and photoelectrocatalytic performance. Junction of CoFe2O4 layer on BiVO4 photoanode led to the improvement of photocurrent density to 4.43 mA/cm2 at 1.23 VRHE, which was approximately 4.06 times higher than that of pure BiVO4. Subsequently, the corresponding optimal degradation efficiency toward the tetracycline model contaminant achieved to be 89.1% with total organic carbon removal value of about 43.7% within 60 min. Moreover, the degradation rate constant of CoFe2O4-BiVO4 photoanode in photoelectrocatalytic system was 0.037 min-1, which was about 1.23, 2.64 and 3.70 times higher than the values in photocatalysis, electrocatalysis and PMS only based systems, respectively. In addition, radical scavenging experiments and electron spin resonance spectra indicated a synergy of radical and nonradical coupling process where •OH and 1O2 played vital roles during tetracycline degradation. Plausible photoelectrocatalytic mechanism and degradation pathway were proposed. This work provided an effective strategy to construct peroxymonosulfate assisted photoelectrocatalytic system toward green environmental applications.

Synthesis of Zn0.1 Sn0.1 Cd0.8 Sx Solid Solutions for Photocatalytic Reduction of Cr(VI): Bandgap Structure and Sulfur Vacancy Regulation.

Ternary metal sulfides (TMSs) solid solutions have been regarded as ideal semiconductors in various photocatalytic reactions due to their outstanding redox reversibility, high electron conductivity, and great stability. In this work, a series of Zn0.1 Sn0.1 Cd0.8 Sx (ZSCS) solid solutions were synthesized by a simple hydrothermal method and applied in the photocatalytic reduction of Cr(VI). The Cr(VI) reduction efficiency of ZSCS-5 quickly reached nearly 100% within 3 min under visible light irradiation. The controlling of sulfur content in ZSCS induced the transformation of cubic to hexagonal CdS, regulating the energy band structure and sulfur vacancy (SV ) content, both of which further influenced the redox properties of ZSCS samples. The more negative conduction band position and more sulfur vacancies contributed to the enhanced photocatalytic reduction performance of ZSCS-5 toward Cr(VI). The active species e- , h+ , O2 ⋅- and 1 O2 were all involved and h+ played a pivotal role in the photocatalytic reaction. This work provided an excellent photocatalyst for reduction of Cr(VI) and strongly confirmed the regulation of energy band structure and sulfur vacancies in photocatalysts through controlling the precursor content.

Intercalation of Well-Dispersed Fe2 O3 with SnO2 toward Durable Peroxymonosulfate Activation to Eliminate Antibiotics: Performance and Mechanism.

Sustainable Fe2 O3 /SnO2 with fine interfacial feature derived from FeSnO(OH)5 was prepared and employed for elimination contaminants. The synergistic effect between Fe2 O3 and SnO2 endowed a remarkable degradation performance for tetracycline degradation. Well dispersed SnO2 can function as fine protective layer to enhance the anchoring of iron ions. In addition, SnO2 with excellent conductivity can accelerate electron transfer on the surface of Fe2 O3 , further activation PMS. Approximately 89.3% of tetracycline (TC) was removed in Fe2 O3 /SnO2 /PMS system, which was higher than alone Fe2 O3 /PMS (73.2%) and SnO2 /PMS (39.7%) systems. The operating parameters were evaluated and studied. Electron paramagnetic resonance (EPR) and quenching tests manifested that 1 O2 was primary active specie, and ⋅OH, ⋅SO4 - and ⋅O2 - were participated in the degradation process. Besides, degradation pathways were proposed by identifying the intermediate products. This work is expected to offer a potential design for construction eco-friendly heterogeneous catalyst toward wastewater treatment.

Junction of ZnmIn2S3+m and bismuth vanadate as Z-scheme photocatalyst for enhanced hydrogen evolution activity: The role of interfacial interactions.

A series of ZnmIn2S3+m photocatalysts were synthesized to show tunable band gap energy with the variation of Zn/S atomic ratio. The junction of ZnmIn2S3+m and BiVO4 led to intimate interfacial contacts. Both experimental and theoretical results implied that electrons flowed from ZnmIn2S3+m to BiVO4 at the ZnmIn2S3+m/BiVO4 interface to form built-in electric field due to the variation of Fermi level, which promised Z scheme charge transfer feature for improving separation of charge carriers for enhanced photocatalytic performance. A higher degree of charge transfer process occurred for Zn2In2S5/BiVO4 heterostructure promised stronger built-in electric field, higher charge separation efficiency and improved photocatalytic activity in comparison to ZnIn2S4/BiVO4 and Zn3In2S6/BiVO4 heterojunctions. The optimal hydrogen production rate of Zn2In2S5/BiVO4 photocatalyst is 8.42 mmol•g-1•h-1 with apparent quantum yield of 22.32 % at 435 nm, which is about 2.2 and 1.5 times higher than that of ZnIn2S4/BiVO4 and Zn3In2S6/BiVO4, respectively.

Durable and eco-friendly peroxymonosulfate activation over cobalt/tin oxides-based heterostructures for antibiotics removal: Insight to mechanism, degradation pathway.

Potential leaching of Co ions could decrease the catalytic activity and cause secondary pollution of water, thereby threatening ecological safety and human health. In response, the in-situ generation of well-dispersed Co2SnO4 and SnO2 with fine interfacial feature was constructed for PMS activation toward efficient tetracycline degradation and lower cobalt ion leaching feature. The synergistic effect of Co2SnO4 and SnO2 endowed Co2SnO4-SnO2 an outstanding catalytic performance for tetracycline degradation in alkaline condition. Meanwhile, the catalysts can effectively degrade the quinolones, dyes and mixture pollutant solution. The excellent performance can attributed to the in-situ introduction of SnO2, which stabilizes the microstructure and provides an effective electronic pathway to enhance the activity of Co2SnO4 in the Co2SnO4-SnO2. In optimized condition, the tetracycline degradation efficiency was enhanced to 94.9% within 20 min and maintained the stability at least four cycles. The degradation rate constant of Co2SnO4-SnO2 was 0.149 min-1, which was about 1.93, 2.98, 11.5 times higher than of Co2SnO4, Co3O4 and SnO2, respectively. Notably, the leaching performance of Co2SnO4-SnO2 was greatly suppressed to be 7.45 ug/L, which was lower than that of Co2SnO4 (6.41 mg/L) and Co3O4 (1.12 mg/L). Radical quenching and EPR experiments showed that singlet oxygen (1O2), rather than hydroxyl active species and sulfate radicals, played a predominating role for PMS activation in the Co2SnO4-SnO2/PMS system. The intermediates and degradation routes for tetracycline degradation were characterized by liquid chromatograph-tandem mass spectrometry. This study expected to provide a novel strategy to construct heterostructural catalysts with lower cobalt ion leaching for the activation of PMS.

S-scheme bismuth vanadate and carbon nitride integrating with dual-functional bismuth nanoparticles toward co-efficiently removal formaldehyde under full spectrum light.

It is crucial to develop more effective photocatalysts in the field of clean environment. In response, the S-scheme BiVO4/g-C3N4 heterojunction modified by in situ reduced non-noble metal Bi nanoparticles was used to synergistically degrade formaldehyde under full spectral irradiation. The results, that investigated by careful characterizations and density functional theory (DFT) calculations, proved that BiVO4/g-C3N4 form an S-scheme heterojunction, which can effectively improve the separation efficiency of photogenic carriers and maintain the original strong redox capability of semiconductor materials. The SPR effect of Bi elemental substance enhanced the optical response and provided more oxidative species. Thus, the photocatalytic activity of BiVO4/Bi/g-C3N4 was significantly improved through their joint efforts, that the degradation efficiency of HCHO (800 ppm) for 6 h is 96.39% under 300 W Xenon lamp without filter with the pseudo-second-order rate constant of 4.16 ppm-1·h-1 and CO2 selectivity of 98.41%. Surprisingly, the degradation efficiency also reached to 49.35% and 32.23% under visible and near-infrared light irradiation, respectively. Moreover, we also tested its photocatalytic decomposition effect on formaldehyde in coatings, indicating that it has a broad prospect in future coatings applications. This study may provide an expected photocatalyst, an efficient non-noble metal modified S-scheme heterojunction, to degrade volatile organic gases under a broad spectrum light.

Double defective group modified nitrogen-deficient carbon nitride with bimetallic PtSn as a cocatalyst for efficient photocatalytic hydrogen evolution up to 765 nm.

Cyano- and urea-defective group co-modified nitrogen-deficient carbon nitride with PtSn as a cocatalyst was constructed to optimize the optical and electronic structure as well as the photocatalytic activity. Defective engineering over carbon nitride gave rise to a stronger light absorption in the visible and near-infrared regions, more negative conduction band edge potential and more efficient separation behavior of photogenerated charge carriers. The optimal photocatalyst exhibited a high hydrogen yield of 2.96 mmol g-1 h-1 with an apparent quantum yield of 8.42% at 435 nm. Moreover, the photocatalytic hydrogen generation capability was maintained under illumination up to 765 nm with an apparent quantum yield of 0.076%.

Structural Insight on Defect-Rich Tin Oxide for Smart Band Alignment Engineering and Tunable Visible-Light-Driven Hydrogen Evolution.

Herein, a series of defect-rich tin oxides, SnxOy, were synthesized with tunable Sn2+/Sn4+ composition ratio and defect chemistry, aiming to explore the impact of local structural modulation, non-stoichiometric chemistry, and defective center on the modulation of band gap values, band edge potential positions, and photocatalytic hydrogen evolution performance. The phase structure, morphology, surface component, and photoelectric properties were analyzed by multiple testing methods. The modulation of the Sn2+/Sn4+ molar ratio was analyzed by X-ray photoelectron spectroscopy and the spectra of Mossbauer and electron spin resonance, which indicated the existence of interstitial tin and oxygen vacancy, predicting a highly disordered local structure. In addition, the photocatalytic activity was evaluated by water splitting for hydrogen production under visible light. The optimal photocatalytic activity toward H2 production rate reached 58.6 µmol·g-1·h-1 under visible light illumination. However, the photocatalytic activity gradually decreased with an increase of synthetic temperature. Much higher Sn2+/Sn4+ molar ratio in the present defective tin oxide gave rise to more negative band edge potentials for hydrogen production. Meanwhile, the driving force was decreased with the diminished Sn2+. Large amounts of hydroxyl groups, Sn2+, and relatively negative potential of conduction band in non-stoichiometric SnxOy play critical roles in visible light harvesting and photocatalytic water splitting. Furthermore, the relationships among crystal structure, electronic properties, and photocatalytic activities were clarified by theoretical calculation. This work provides a novel strategy for the development of highly efficient photocatalytst by regulating the internal electronic structure and surface defects.

Waste control by waste: Fenton-like oxidation of phenol over Cu modified ZSM-5 from coal gangue.

Coal gangue and phenol are two main pollutants in coal mining and processing. Using coal gangue as raw material, a series of Cu modified ZSM-5 (Cu/ZSM-5) catalysts were developed to remove phenol through heterogeneous Fenton-like reaction. This procedure implies the concept of waste control by waste. The characterization results showed that Cu modification had no obvious impact on the MFI (Mobile Five) structure of ZSM-5. Copper ions were presented as doping element (substitution of Na and Al ions) and copper oxides on ZSM-5 surface. The XPS spectra suggested the co-existence of Cu2+ and Cu+. As a consequence of well-defined experimental parameters, 7% Cu/ZSM-5 performed excellent activity and stability for the degradation and mineralization of phenol pollutant, which could degrade phenol completely within 30min and the TOC removal efficiency could reach 63% within 60min and 92% within 8h. ESR and radicals capturing experiments demonstrated that OH and 1O2 played the dominant roles in the Fenton-like reaction. In combination with XPS, ESR and catalytic tests, it's found that the redox cycling of Cu+/Cu2+ played critical roles in accelerating the active radical generation in this Fenton-like system.

Synthesis and Characterization of Modified BiOCl and Their Application in Adsorption of Low-Concentration Dyes from Aqueous Solution.

The synthesis and characterization of BiOCl and Fe3+-grafted BiOCl (Fe/BiOCl) is reported that are developed as efficient adsorbents for the removal of cationic dyes rhodamine B (RhB) and methylene blue (MB) as well as anionic dyes methyl orange (MO) and acid orange (AO) from aqueous solutions with low concentration of 0.01~0.04 mmol/L. Characterizations by various techniques indicate that Fe3+ grafting induced more open porous structure and higher specific surface area. Both BiOCl and Fe/BiOCl with negatively charged surfaces showed excellent adsorption efficiency toward cationic dyes, which could sharply reach 99.6 and nearly 100% within 3 min on BiOCl and 97.0 and 98.0% within 10 min on Fe/BiOCl for removing RhB and MB, respectively. However, Fe/BiOCl showed higher adsorption capacity than BiOCl toward ionic dyes. The influence of initial dye concentration, temperature, and pH value on the adsorption capacity is comprehensively studied. The adsorption process of RhB conforms to Langmuir adsorption isotherm and pseudo-second-order kinetic feature. The excellent adsorption capacities of as-prepared adsorbents toward cationic dyes are rationalized on the basis of electrostatic attraction as well as open porous structure and high specific surface area. In comparison with Fe/BiOCl, BiOCl displays higher selective efficiency toward cationic dyes in mixed dye solutions.

Comparative Transcriptomic Analysis of Two Brassica napus Near-Isogenic Lines Reveals a Network of Genes That Influences Seed Oil Accumulation.

Rapeseed (Brassica napus) is an important oil seed crop, providing more than 13% of the world's supply of edible oils. An in-depth knowledge of the gene network involved in biosynthesis and accumulation of seed oil is critical for the improvement of B. napus. Using available genomic and transcriptomic resources, we identified 1,750 acyl-lipid metabolism (ALM) genes that are distributed over 19 chromosomes in the B. napus genome. B. rapa and B. oleracea, two diploid progenitors of B. napus, contributed almost equally to the ALM genes. Genome collinearity analysis demonstrated that the majority of the ALM genes have arisen due to genome duplication or segmental duplication events. In addition, we profiled the expression patterns of the ALM genes in four different developmental stages. Furthermore, we developed two B. napus near isogenic lines (NILs). The high oil NIL, YC13-559, accumulates significantly higher (∼10%) seed oil compared to the other, YC13-554. Comparative gene expression analysis revealed upregulation of lipid biosynthesis-related regulatory genes in YC13-559, including SHOOTMERISTEMLESS, LEAFY COTYLEDON 1 (LEC1), LEC2, FUSCA3, ABSCISIC ACID INSENSITIVE 3 (ABI3), ABI4, ABI5, and WRINKLED1, as well as structural genes, such as ACETYL-CoA CARBOXYLASE, ACYL-CoA DIACYLGLYCEROL ACYLTRANSFERASE, and LONG-CHAIN ACYL-CoA SYNTHETASES. We observed that several genes related to the phytohormones, gibberellins, jasmonate, and indole acetic acid, were differentially expressed in the NILs. Our findings provide a broad account of the numbers, distribution, and expression profiles of acyl-lipid metabolism genes, as well as gene networks that potentially control oil accumulation in B. napus seeds. The upregulation of key regulatory and structural genes related to lipid biosynthesis likely plays a major role for the increased seed oil in YC13-559.

Constructing Bi24O31Cl10/BiOCl heterojunction via a simple thermal annealing route for achieving enhanced photocatalytic activity and selectivity.

This work reports on the construction of a Bi24O31Cl10/BiOCl heterojunction via a simple thermal annealing method. The X-ray diffraction (XRD) results indicated that the phase transformation from BiOCl to Bi24O31Cl10 could be realized during the thermal annealing process. The high-resolution transmission electron microscopy (HRTEM) images, X-ray photoelectron spectroscopy (XPS) binding energy shifts, Raman spectra and Fouier transform infrared spectroscopy (FT-IR) spectra confirmed the formation of the Bi24O31Cl10/BiOCl heterojunction. The obtained Bi24O31Cl10/BiOCl photocatalyst showed excellent conversion efficiency and selectivity toward photocatalytic conversion of benzyl alcohol to benzaldehyde under visible light irradiation. The radical scavengers and electron spin resonance (ESR) results suggested that the photogenerated holes were the dominant reactive species responsible for the photocatalytic oxidation of benzyl alcohol and superoxide radicals were not involved in the photocatalytic process. The in-situ generation of Bi24O31Cl10/BiOCl heterojunction may own superior interfacial contact than the two-step synthesized heterojunctions, which promotes the transfer of photogenerated charge carriers and is favorable for excellent photocatalytic activities.

Dynamic transcriptome analysis reveals AP2/ERF transcription factors responsible for cold stress in rapeseed (Brassica napus L.).

The APETALA2/ethylene response factor (AP2/ERF) transcription factor (TF) superfamily plays an important regulatory role in signal transduction of the plant responses to various stresses including low temperature. Significant progress has been made in understanding the mechanism of cold resistance in Brassica napus, an important oilseed crop. However, comprehensive studies on the induction and activity of these TFs under low temperature have been lacking. In this study, 132 AP2/ERF genes were identified by transcriptome sequencing of rapeseed leaves exposed to 0, 2, 6, 12, and 24 h of low (4 °C) temperature stress. The genes were classified into 4 subfamilies (AP2, DREB, ERF, and RAV) and 13 subgroups, among which the DREB subfamily and ERF subfamily contained 114 genes, no genes were assigned to soloist or DREB A3 subgroups. One hundred and eighteen genes were located on chromosomes A1 to C9. GO functional analysis and promoter sequence analysis revealed that these genes are involved in many molecular pathways that may enhance cold resistance in plants, such as the low-temperature responsiveness, methyl jasmonate, abscisic acid, and ethylene-responsiveness pathways. Their expression patterns revealed dynamic control at different times following initiation of cold stress; the RAV and DREB subfamilies were expressed at the early stage of cold stress, whereas the AP2 subfamily was expressed later. Quantitative PCR analyses of 13 cold-induced AP2/ERF TFs confirmed the accuracy of above results. This study is the first dynamic analysis of the AP2/ERF TFs responsible for cold stress in rapeseed. These findings will serve as a reference for future functional research on transcription in rapeseed.

Enhanced luminescence of CaWO4:Eu3+ loaded in SBA-16.

CaWO4:Eu3+/SBA-16 composites with various molar ratios of Eu3+ to CaWO4(x) were successfully synthesized by impregnation and subsequent hydrothermal treatment. The physicochemical properties of the resultant composites were well characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR) and luminescence spectra. The results demonstrated that the resultant CaWO4:Eu3+/SBA-16 composites still had ordered mesostructure, i.e., the loading of CaWO4:Eu3+ has little impact on the uniform mesostructure of the host matrix SBA-16, but just reduced the specific surface area and pore volume of the host matrix. Furthermore, the CaWO4:Eu3+/SBA-16 composites with various x showed enhanced luminescent properties than the pure CaWO4:Eu3+ counterparts, and reached the highest luminescence intensity when x was 3%.

Facile synthesis and enhanced near infrared luminescent properties of CaWO4:Ln3+/Na+ (Ln = Nd, Er, and Yb) core/shell microstructure.

In this work, we reported the fabrication and characterization of CaWO4:Ln3+/Na+ (Ln = Nd, Er, and Yb) core/shell microspheres via a facile hydrothermal method in the presence of citric acid and PVP. The samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, infrared spectra, and photoluminescence. It's found that citric acid could modulate the nucleation and growth of CaWO4 nanocrystals and enable the co-incorporation of Na+ and Ln3+ (Ln = Nd, Er, and Yb) into CaWO4 lattice. Meanwhile, PVP controlled the assembly of CaWO4 nanocrystals into a core/shell spherical structure. All CaWO4:Ln3+/Na+ (Ln = Nd, Er, and Yb) core/shell microspheres exhibited intense near-IR luminescence. In comparison with CaWO4:Ln3+/Na+ nanocrystals, the self-assembled core/shell nanoarchitechtures showed highly enhanced IR luminescent properties due to the depressing of surface energy-loss.

Chiral [NaMnIIMnIII3] and [Na2MnII2MnIII6] clusters constructed by chiral multidentate Schiff-base ligands: synthesis, structures, CD spectra and magnetic properties.

Two pairs of novel enantiomerically chiral clusters R/S-[NaMn(II)Mn(III)3L3(µ3-O)] (R/S-1) and R/S-[Na2Mn(II)2Mn(III)6L6(µ3-O)2] (R/S-2) have been obtained via the self-assembly of R/S-H2L Schiff base ligands and different auxiliary ligands (N3(-), dca(-)) with divalent manganese salt in an air-exposed methanol-ethanol solution. The structures of R/S-1 and R/S-2 were characterized by single-crystal X-ray diffraction analysis and powder X-ray diffraction. When the dicyanamide anion serves as an auxiliary ligand in the assembling reaction system, a pair of enantiomeric clusters R/S-[NaMn(II)Mn(III)3L3(µ3-O)] (R-1 and S-1) with a trigonal bipyramid configuration were obtained, while another pair of enantiomeric clusters R/S-[Na2Mn(II)2Mn(III)6L6(µ3-O)2] (R-2 and S-2) were formed in the case of the azide. Interestingly, the skeleton configuration of R/S-2 can be described as a 3-fold EO-azide bridging double trigonal bipyramid of [NaMn(II)Mn(III)3L3(µ3-O)]2via Mn(II) vertices. Circular dichroism (CD) spectra demonstrated the enantiomeric nature of the two pairs of clusters. Detailed direct current (DC) magnetic susceptibility studies in the temperature range 2-300 K suggested that R-1 and R-2 showed predominantly antiferromagnetic interactions between the manganese centers.

Molecular sensitized GdF3:Eu3+ for color tuning and highly enhanced luminescent properties.

In this work, we report on the preparation of [2,3-f]pyrazino[1,10]phenanthroline-2,3-dicarboxylic anions (PPDB(2-)) modified GdF3:Eu(3+) nanocrystals by a versatile ligand exchange approach for highly enhanced luminescent properties. The samples were carefully characterized by X-ray powder diffraction, transmission electron microscopy, infrared spectra and photoluminescence. It is found that all GdF3:Eu(3+) nanoparticles were entirely composed of homogeneous nano-spheres with an average diameter of about 30-35 nm. After PPDB(2-) capping, GdF3:Eu(3+) nanocrystals exhibited higher color purity and shorter lifetime time, which can be well recognized as a consequence of surface structure modification and local symmetry alteration near Eu(3+) ions. High color purity and short lifetime of PPDB(2-) modified GdF3:Eu(3+) nanocrystals predict highly enhanced red luminescence, which showed the quantum efficiency of ~34%. The highly enhanced luminescent property enables its potential application as chemosensor for detection of heavy metal ions.