Highly efficient capture of iodine vapor by [Mo3S13]2- intercalated layered double hydroxides.

From the swollen LDH, bulky [Mo3S13]2- anions are facilely introduced into the LDH interlayers to assemble the Mo3S13-LDH composite, which exhibits excellent iodine capture performance and good irradiation resistance. The positive-charged LDH layers may disperse the [Mo3S13]2- uniformly within the interlayers, providing abundant adsorption sites for effectively trapping iodine. The Mo-S bond serving as a soft Lewis base has strong affinity to I2 with soft Lewis acidic characteristic, which is conducive to improvement of iodine capture via physical sorption. Besides, chemisorption has a significant contribution to the iodine adsorption. The S22-/S2- in [Mo3S13]2- can reduce the I2 to [I3]- ions, which are facilely fixed within the LDH gallery in virtue of electrostatic attraction. Meanwhile, the S22-/S2- themselves are oxidized to S8 and SO42-, while Mo4+ is oxidized (by O2 in air) to Mo6+, which combines with SO42- forming amorphous Mo(SO4)3. With the collective interactions of chemical and physical adsorption, the Mo3S13-LDH demonstrates an extremely large iodine adsorption capacity of 1580 mg/g. Under γ radiation, the structure of Mo3S13-LDH well maintains and iodine adsorption capability does not deteriorate, indicating the good irradiation resistance. This work provides an important reference to tailor cost-effective sorbents for trapping iodine from radioactive nuclear wastes.

[Sn2S6]4- Anion-Intercalated Layered Double Hydroxides for Highly Efficient Capture of Iodine.

The development of low-cost and high-efficiency iodine sorbents is of great significance for the control of nuclear pollution. In this work, we intercalate the tin sulfide cluster of [Sn2S6]4- to Mg/Al-type layered double hydroxides to obtain Sn2S6-LDH, which exhibits highly efficient capture performance of iodine vapor and iodine in solutions. The dispersion effect of the positively charged LDH layers contributes to the adequate exposure of [Sn2S6]4- anions, providing plentiful adsorption sites. For iodine vapor, Sn2S6-LDH showed an extremely large iodine capture capacity of 2954 mg/g with a large contribution from physisorption. For iodine in solutions, a significantly large sorption capacity of 1308 mg/g was achieved. During iodine capture, I2 molecules were reduced to I- ions (by S2- in [Sn2S6]4-), which then reacted with Sn4+ to form SnI4, where the molar amount of captured iodine is 4-fold that of Sn. Besides, the as-reduced I- combined with I2 again to generate [I3]-, which then entered the LDH interlayers to maintain electric neutrality. While reducing iodine, S2- itself in [Sn2S6]4- was oxidized to S8, which further combined with SnI4 to form a novel compound of SnI4(S8)2. The excellent iodine capture capability endows Sn2S6-LDH with a promising application in trapping radioactive iodine.

Intercalation of salicylaldoxime into layered double hydroxide: Ultrafast and highly selective uptake of uranium from different water systems via versatile binding modes.

We report the first example of MgAl layered double hydroxide intercalated with salicylaldoxime (SA-LDH) which exhibits excellent uranium (U(VI)) capture performance. In U(VI) aqueous solutions, the SA-LDH shows a tremendous maximum U(VI) sorption capacity (qmU) of 502 mg·g-1, surpassing most known sorbents. For the aqueous solution with an initial U(VI) concentration (C0U) of âˆ¼ 10 ppm, ≥99.99 % uptake is achieved in a wide pH range of 3-10. At C0U âˆ¼ 20 ppm, >99 % uptake is reached within only 5 min, and pseudo-second-order kinetics rate constant (k2) of 44.9 g·mg-1·min-1 reaches the record value, placing the SA-LDH amongst the fastest U adsorbing materials reported to date. In contaminated seawater with 35 ppm of U while highly concentrated metal ions of Na+, Mg2+, Ca2+, and K+, the SA-LDH still displays exceptionally high selectivity and ultrafast extraction for UO22+, giving >95 % uptake of U(VI) within 5 min, and the k2 value of 0.308 g·mg-1·min-1 for seawater surpasses most reported values for aqueous solutions. Versatile binding modes toward U by SA-LDH, including complexation (UO22+ with SA- and/or CO32-), ion exchange and precipitation, contribute to the preferable uptake of U at different concentrations. X-ray absorption fine structure (XAFS) analyses demonstrate that one uranyl ion (UO22+) binds to two SA- anions and two H2O molecules forming 8-coordinated configuration. The U coordinates with O atom of the phenolic hydroxyl group and N atom of the -CN-O- group of SA-, forming a stable six-membered ring motif, which endows the fast and robust capture of U. The wonderful uranium trapping ability makes the SA-LDH among the best adsorbent used for uranium extraction from various solution systems including seawater.

Layered double hydroxide intercalated with dimethylglyoxime for highly selective and ultrafast uptake of uranium from seawater.

In this study, we demonstrate the first example of a MgAl layered double hydroxide intercalated by a ketoxime compound (dimethylglyoxime, DMG), that is, MgAl-DMG-LDH (abbr. DMG-LDH), which exhibits excellent capture of uranium (U(VI)) both at high (ppm) and low (ppb) concentrations. The as-formed DMG-LDH shows an enormous maximum U(VI) sorption capacity (qUm) of 380 mg g-1 and an exceptionally rapid sorption rate (k2 = 2.97 g mg-1 min-1), reaching a high uptake of 99.14% within 5 min. For natural and contaminated seawater with high concentrations of Na+, Ca2+, Mg2+ and K+ concomitant cations, the DMG-LDH still can trap ∼85% U, displaying highly effective sorption toward U. The interaction mechanism between UO22+ and DMG2- provides an important reference for the development of highly effective capture of U(VI) by ketoxime materials. The DMG-LDH is currently the best ketoxime material for uranium extraction from nuclear waste and seawater.

Removal of CrO42-, a Nonradioactive Surrogate of 99TcO4-, Using LDH-Mo3S13 Nanosheets.

Removal of chromate (CrO42-) and pertechnetate (TcO4-) from the Hanford Low Activity Waste (LAW) is beneficial as it impacts the cost, life cycle, operational complexity of the Waste Treatment and Immobilization Plant (WTP), and integrity of vitrified glass for nuclear waste disposal. Here, we report the application of [MoIV3S13]2- intercalated layer double hydroxides (LDH-Mo3S13) for the removal of CrO42- as a surrogate for TcO4-, from ppm to ppb levels from water and a simulated LAW off-gas condensate of Hanford's WTP. LDH-Mo3S13 removes CrO42- from the LAW condensate stream, having a pH of 7.5, from ppm (∼9.086 × 104 ppb of Cr6+) to below 1 ppb levels with distribution constant (Kd) values of up to ∼107 mL/g. Analysis of postadsorbed solids indicates that CrO42- removal mainly proceeds by reduction of Cr6+ to Cr3+. This study sets the first example of a metal sulfide intercalated LDH for the removal of CrO42-, as relevant to TcO4-, from the simulated off-gas condensate streams of Hanford's LAW melter which contains highly concentrated competitive anions, namely F-, Cl-, CO32-, NO3-, BO33-, NO2-, SO42-, and B4O72-. LDH-Mo3S13's remarkable removal efficiency makes it a promising sorbent to remediate CrO42-/TcO4- from surface water and an off-gas condensate of nuclear waste.

The confinement effect of layered double hydroxides on intercalated pyromellitic acidic anions and highly selective uranium extraction from simulated seawater.

Oxygen-rich pyromellitic acidic anions (PMA4-) have been intercalated into MgAl-layered double hydroxides to fabricate the MgAl-PMA-LDH (abbr. PMA-LDH) composite exhibiting excellent adsorption performance toward uranium (U(VI)). Benefiting from the large number of functional groups of -COO-, the PMA-LDH displays an extremely large maximum U adsorption capacity (qUm) of 352 mg g-1 and an ultra-fast sorption rate, reaching uptakes of ∼97% within 30 min and >99% in 1 h at the initial U concentration (CU0) of 113 ppm. Over a very wide pH range of 5-11, high U removals (>93%) are achieved at CU0 = 105 ppm. Moreover, in the presence of highly concentrated competitive ions, ultra-high selectivity of UO22+ is observed, giving a very large distribution coefficient (Kd) of ∼106 mL g-1. Moreover, the PMA-LDH exhibits effective capture of UO22+ in contaminated simulated seawater, showing high uptakes of >93% at CU0 ∼ 10 ppm and >98% at CU0 ∼ 100 ppm. The dispersion effect of LDH layers may contribute to the increase of U adsorption capacity, and the confinement effect of LDH is conducive to the improvement of sorption selectivity toward U. The exploration of the interaction mechanism of UO22+ with PMA4- confined within the LDH gallery offers an important basis for the fabrication of new kinds of organic/inorganic hybrid materials. The PMA-LDH is a highly effective adsorbent which can be applied to uranium extraction from seawater and uranium disposal in nuclear wastewater.

Mo3 S13 2- Intercalated Layered Double Hydroxide: Highly Selective Removal of Heavy Metals and Simultaneous Reduction of Ag+ Ions to Metallic Ag0 Ribbons.

We demonstrate a new material by intercalating Mo3 S13 2- into Mg/Al layered double hydroxide (abbr. Mo3 S13 -LDH), exhibiting excellent capture capability for toxic Hg2+ and noble metal silver (Ag). The as-prepared Mo3 S13 -LDH displays ultra-high selectivity of Ag+ , Hg2+ and Cu2+ in the presence of various competitive ions, with the order of Ag+ >Hg2+ >Cu2+ >Pb2+ ≥Co2+ , Ni2+ , Zn2+ , Cd2+ . For Ag+ and Hg2+ , extremely fast adsorption rates (≈90 % within 10 min, >99 % in 1 h) are observed. Much high selectivity is present for Ag+ and Cu2+ , especially for trace amounts of Ag+ (≈1 ppm), achieving a large separation factor (SFAg/Cu ) of ≈8000 at the large Cu/Ag ratio of 520. The overwhelming adsorption capacities for Ag+ (qm Ag =1073 mg g-1 ) and Hg2+ (qm Hg =594 mg g-1 ) place the Mo3 S13 -LDH at the top of performing sorbent materials. Most importantly, Mo3 S13 -LDH captures Ag+ via two paths: a) formation of Ag2 S due to Ag-S complexation and precipitation, and b) reduction of Ag+ to metallic silver (Ag0 ). The Mo3 S13 -LDH is a promising material to extract low-grade silver from copper-rich minerals and trap highly toxic Hg2+ from polluted water.

Single Treatment of Vitamin D3 Ameliorates LPS-Induced Acute Lung Injury through Changing Lung Rodentibacter abundance.

Acute lung injury (ALI) is characterized by severe inflammation. Vitamin D3 is discussed to reduce inflammation in ALI, but the mechanism is not well understood. This study assesses the effect of different calcitriol administration strategies on inflammation and the lung microbiota composition in ALI. In a mouse model, the alveolus and airway pathology are assessed by immunohistology. mRNA expression is determined by Real-Time Quantitative PCR and protein expressions is detected by Western-blotting. The composition of microbiota is performed by 16s DNA high-throughput sequencing. Short-term vitamin D3 supplementation prevents lipopolysaccharide-induced ALI by preventing pro-inflammatory cytokines including interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α). In contrast, long-term treatment over 3 days, 6 days, or 10 days had no such effect. Short-term vitamin D3, but not long-term pretreatment significantly reduces the phosphorylation of signal transducer and activator of transcription 3 and suppressor of cytokine signaling 3, but upregulates the phosphorylation of inhibitor of nuclear factor-κ-gene binding. Furthermore, an increased relative abundance of Rodentibacter genus in LPS-challenged mice bronchoalveolar lavage fluid is observed, which is sensitive to short-term vitamin D3 treatment, effectively alleviating the Rodentibacter abundance. Correlation analysis shows that the load of Rodentibacter positively correlated with the IL-1ß, IL-6, and TNF-α gene expression. The data support that a single administration of vitamin D3 may work as an adjuvant therapy for acute lung inflammation.

Highly efficient capture of uranium from seawater by layered double hydroxide composite with benzamidoxime.

Through swelling/restoration reaction, benzamidoxime (BAO) is introduced into MgAl-LDH interlayers to assemble a new composite of MgAl-BAO-LDH (abbr. BAO-LDH). Wet samples of the BAO-LDH obtained by washing with diverse solvents are present in colloidal state, which facilitates the fabrication of thin film adsorbents convenient for actual application. After drying, the assembled sample exhibits floral morphology composed of thin nanosheets, much different from hexagonal morphology of NO3- intercalated MgAl-LDH precursor (NO3-LDH), demonstrating a phenomenon rarely found in swelling/restoration. The BAO-LDH depicts an extremely large maximum sorption capacity (qmU) of 327 mg·g-1 and ultra-high selectivity for U. At low U concentrations (5-10 ppm), nearly complete capture (~100%) is achieved in a wide pH range of 3-11, while at high U concentrations (110 ppm), quite high U removals (≥93.0%) are obtained at pH = 6-8, meaning perfect suitability for trapping U from seawater. For natural seawater containing trace amounts of U (3.93 ppb) coexisting with high concentration of competitive ions, the BAO-LDH displays significantly high U removal (87%). Complexation between interlayer BAO (N and O as ligands) with UO22+ and synergistic interactions of LDH layer hydroxyls with UO22+ contribute to the highly effective uranium capture. All results demonstrate the BAO-LDH is a promising adsorbent applied in seawater uranium extraction and nuclear wastewater disposal.

SDC/OS-LDH composite for highly sensitive fluorescence detection of Fe3+ at a much lower concentration.

In this work, we demonstrate the tunable luminescence of newly synthesized SDC/OS Mg/Al-LDH composites (SDC is 4,4'-stilbenedicarboxylic acid; OS is 1-octanesulfonic acid sodium; LDH is layered double hydroxide) and their application in fluorescence sensing to detect Fe(iii) ions. Through an ion-exchange method, the SDC2- and OS- anions with changed molar ratios are intercalated into the LDH interlayers to obtain composites of SDCxOS1-x-LDH (x = 0.02, 0.05, and 0.10). In the solid state, the optimized SDC0.05OS0.95-LDH exhibits a blue emission (441 nm) with a 54 nm blue-shift compared with SDC-Na solid salt (495 nm). In a delaminated state, the colloidal suspension of SDC0.05OS0.95-LDH in formamide (FM) also gives a blue emission at 444 nm in comparison to the 451/468 nm emissions of the FM solution of free SDC2- anions, and the luminescence intensity of the exfoliated composite is ∼28 times higher than that of the SDC2- anions. The SDC0.05OS0.95-LDH composite could be utilized in chemical fluorescence sensing for detecting Fe3+ ions. In aqueous solutions with extremely low Fe3+ concentrations of 0.18-1.78 µM (0.01-0.1 ppm), the composite gives a large quenching constant of 2.34 × 105 M-1, and an ultralow detection limit of 6.12 × 10-8 M. This work may provide a highly effective while simple method for the detection of Fe3+ in a small concentration range.

A multi-institutional and cross-sectional study on empathy in Chinese medical students: differences by student cadre or not, future career preference, and father's education status.

BACKGROUND: The aims of this study were to examine the factor structure of the Chinese version of the Jefferson Scale of Empathy for medical students (JSE-S) and investigate differences in empathy scores among Chinese medical students according to gender, student cadre or not, future career preference, and parents' education. METHODS: Medical students from three universities completed an online questionnaire containing the JSE-S. Exploratory factor analysis was conducted to determine the factor structure, and group comparisons of empathy scores were examined via t-tests and analysis of variance. RESULTS: Four factors emerged from the factor analysis: "perspective taking," "compassionate care," "standing in the patient's shoes," and an uninterpretable factor. The results indicated that students who were female, held positions as student cadres, preferred to become a doctor, and whose fathers had a high school education or below tended to have more empathy. CONCLUSIONS: Overall, the findings provide information on the dimensions of empathy applicable to Chinese medical students and confirm the factors found in the original measure. The dimensions have implications for developing empathy among medical students throughout the world. Educators can use the information to design interventions to foster empathy among students in the context of medical education reform in many countries, including China.

Hierarchical microsphere assembled by nanoplates embedded with MoS2 and (NiFe)S x nanoparticles as low-cost electrocatalyst for hydrogen evolution reaction.

The development of low-cost electrocatalysts with high performance is important to provide sustainable hydrogen energy. In this work, via one-step sulfuration of [Formula: see text] intercalated NiFe-layered double hydroxide (abbr. NiFe-MoO4-LDH), hierarchical microspheres are assembled by intersecting nanoplates (15-30 nm in thickness) which are then decorated with MoS2 and (NiFe)S x nanoparticles (∼25 nm in size). The NiFe-MoO4-LDH is synthesized beforehand by a one-pot hydrothermal reaction. Under sulfuration at 300 °C, 400 °C and 600 °C, the NiFe-MoO4-LDH transforms into multi-metal sulfides of NiFeMoS-T (T is applied temperature). During sulfuration, the confinement effect of LDH limits the growth of metal sulfides, causing formation of nanoparticles of MoS2 and (NiFe)S x to expose more catalytic active sites. In an alkaline medium, NiFeMoS-400 depicts superior performance for hydrogen evolution reaction (HER), giving an overpotential of 210 mV at 10 mA cm-2. A Tafel slope of 88 mV dec-1 indicates a mixed Volmer-Heyrovsky rate-determining step. The electrode also maintains long-term electrochemical durability during 15 h electrolysis at 25 mA cm-2. The NiFe-MoO4-LDH precursor owns three metal elements (Ni, Fe and Mo), which ensure the formation of polymetallic sulfides, and maximum utilization of the LDH layer and interlayer metals contributes to the optimal electrocatalytic activity. The NiFeMoS nanoassembly is a potential low-cost and high-efficiency electrocatalyst.

Polypyrrole-Mo3S13: An Efficient Sorbent for the Capture of Hg2+ and Highly Selective Extraction of Ag+ over Cu2.

The new material Polypyrrole-Mo3S13 (abbr. Mo3S13-Ppy) is a new material prepared by ion-exchange between Ppy-NO3 and (NH4)2Mo3S13. The Mo3S13-Ppy was designed to exhibit strong selectivity for Ag+ and highly toxic Hg2+ in mixtures with other ions. It displays an apparent selectivity ranking of Hg2+ > Ag+ ≥ Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Pb2+. The strong affinity of Mo3S13-Ppy for Ag+ and Hg2+ was confirmed with extremely high distribution coefficients (Kd) (∼107 mL/g) and remarkable removal efficiencies (>99.99%), resulting in <1 ppb concentrations of these ions. Furthermore, Mo3S13-Ppy achieved excellent separation selectivity for Ag+ from Cu2+ (even at a high Cu2+/Ag+ ratio, the molar ratio of 867 and mass ratio of 500) because of the special structure of Mo3S132- and its component Mo4+ and (S2)2-. This is promising for the direct extraction of low-grade silver from copper-rich minerals. The maximum Ag uptake capacity of 408 mg/g is redox-based and surprisingly involves the deposition of large, millimeter sized, metallic silver (Ag0) crystals on the surface of Mo3S13-Ppy.

MoS2/Au0/N-CNT derived from Au(III) extraction by polypyrrole/MoS4 as an electrocatalyst for hydrogen evolution reaction.

The nanotube type MoS42-/polypyrrole (MoS4-Ppy) is newly synthesized which exhibits exceptional uptake capability for Au(III) with a high removal rate of >99.99% and large Kd of >107 mL/g. Through simple calcination, the Au-loaded MoS4-Ppy is successfully converted to nitrogen-doped carbon nanotubes (N-CNT) decorated with MoS2 nanosheets as well as Au0 nanoparticles, forming a novel composite of MoS2/Au0/N-CNT. The conductivity of MoS2/Au/N-CNT is substantially improved by the highly conductive N-CNT and Au0 metal. In addition, the N-CNT can effectively eliminate the aggregation of MoS2 sheets and Au0 particles, thus endowing more exposed active sites. The optimized MoS2/Au0/N-CNT displays good electrocatalytic performance towards hydrogen evolution reaction (HER). For the first time, we demonstrate the MoS4-Ppy is a promising material for efficient extraction and recovery of trace amounts of precious metal Au from gold-bearing leachates, and the subsequent product MoS2/Au/N-CNT can act as an effective HER electrocatalyst. The fabrication process of the composite material can not only remediate water contamination but also reuse precious metals. This dual-use approach opens a new way to explore effective sorbents for recovery of trace of gold and apply them in catalysis and sensing fields.

Lead-Free Broadband Orange-Emitting Zero-Dimensional Hybrid (PMA)3InBr6 with Direct Band Gap.

Low-dimensional organic-inorganic hybrid metal halides have emerged as broadband light emitters for phosphor-converted white light-emitting diodes (WLEDs). Herein, we report a new zero-dimensional (0-D) lead-free metal halide (PMA)3InBr6 [PMA+: (C6H5CH2NH3)+] that crystallizes in the monoclinic system with P21/c space group. The structure consists of slightly distorted [InBr6]3- octahedra surrounded by organic PMA+ cations. The direct band gap characteristic of (PMA)3InBr6 was demonstrated by density functional theory calculation, and its relatively wide band gap of 3.78 eV was experimentally determined. Upon 365 nm ultraviolet light excitation, (PMA)3InBr6 exhibited strong broadband orange luminescence with a full-width at half-maximum of ∼132 nm resulting from self-trapped exciton emission, and the photoluminescence quantum yield was determined to be ∼35%. A WLED fabricated by combining the orange-emitting (PMA)3InBr6, a green phosphor Ba2SiO4:Eu2+, and a blue phosphor BaMgAl10O17:Eu2+ exhibited a high color-rendering index of 87.0. Our findings indicate that the organic-inorganic hybrid (PMA)3InBr6 may have potential for luminescence-based applications.

Grape Seed Procyanidin Extract (GSPE) Improves Goat Sperm Quality When Preserved at 4 °C.

Grape seed procyanidin extract (GSPE) has been shown to possess antioxidative effects. This experiment was designed to study the effect of GSPE during the liquid storage of goat semen. Semen samples were collected from six sexually mature goats. The samples were treated with different concentrations of GSPE (10, 30, 50, and 70 mg/L) in basic diluent and stored at 4 °C for 120 h; samples without GSPE were used as the control group. The results showed that sperm motility, acrosome membrane integrity, mitochondrial activity, plasma membrane integrity, total antioxidative capacity (T-AOC), catalase (CAT) activity, and superoxide dismutase (SOD) activity in the treatment groups were significantly higher than in the control group, whereas malondialdehyde (MDA) content was lower than in the control group (p < 0.05). In the treatment group, sperm quality in the 30 mg/L GSPE group was significantly higher than the other groups (p < 0.05). Furthermore, artificial insemination (AI) results showed that litter sizes were higher in the 30 mg/L GSPE group than in the control group (p < 0.05). In summary, this experiment showed that adding GSPE to the basic diluent improved sperm quality and that 30 mg/L of GSPE was the most suitable concentration for the liquid preservation of goat semen at 4 °C.

Morphology-Controlled Synthesis of Ni-MOFs with Highly Enhanced Electrocatalytic Performance for Urea Oxidation.

MOFs present potential application in electrocatalysis. The structure-activity of the Ni-MOFs with different morphologies, nanowires, neurons, and urchins is systemically investigated. The Ni-MOFs were controllably synthesized via the facile solvothermal method. Among them, the Ni-MOF nanowires are endowed with the highest electrocatalytic activity due to the unique structure, more exposed active sites, lower charge transfer resistance, and the fast and direct electron transfer in 1D structures. The typical morphology of the Ni-MOF nanowires is ca. 10 nm in diameter and several micrometers in length. When employed as an electrocatalyst in urea oxidation reaction, it exhibits a lower overpotential than and superior stability to the Ni-MOFs with other morphologies. Ni-MOF nanowires require a potential of ∼0.80 V (vs Ag/AgCl) to obtain 160 mA cm-2. In addition, after continuous electrocatalyzing for 3600 s at 0.40 V (vs Ag/AgCl), the current density retention of Ni-MOF nanowires could still reach more than 60% (>12 mA cm-2), which demonstrates Ni-MOF nanowires as promising electrocatalysts for urea oxidation.

Needle grass-like cobalt hydrogen phosphate on Ni foam as an effective and stable electrocatalyst for the oxygen evolution reaction.

Exploring efficient non-precious metal electrocatalysts for the oxygen evolution reaction (OER) is a challenging task in sustainable energy systems. Herein, facile and novel three dimensional (3D) needle grass-like CoHPO4·H2O on Ni foam (CoHPO/NF) has been prepared as an effective and robust OER electrocatalyst for the first time. The unique 3D topological structure of CoHPO exposes more electrocatalytic active sites and facilitates mass transport. The coordinated HPO42- anions work as OH- traps to synergistically enhance the process of the OER. Because of these advantages, it exhibits an extraordinary OER performance with a low overpotential of only 350 mV at 50 mA cm-2. Notably, it also exhibits excellent long-term stability. According to the theoretical calculations, the electron structure of the Co was significantly influenced by the coupled HPO42- species, which leads to superior activity for the OER. All the findings imply that CoHPO/NF is a promising material to substitute for noble metals in overall water splitting.

Hierarchical Nanoassembly of MoS2/Co9S8/Ni3S2/Ni as a Highly Efficient Electrocatalyst for Overall Water Splitting in a Wide pH Range.

The design of low-cost yet high-efficiency electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) over a wide pH range is highly challenging. We now report a hierarchical co-assembly of interacting MoS2 and Co9S8 nanosheets attached on Ni3S2 nanorod arrays which are supported on nickel foam (NF). This tiered structure endows high performance toward HER and OER over a very broad pH range. By adjusting the molar ratio of the Co:Mo precursors, we have created CoMoNiS-NF- xy composites ( x: y means Co:Mo molar ratios ranging from 5:1 to 1:3) with controllable morphology and composition. The three-dimensional composites have an abundance of active sites capable of universal pH catalytic HER and OER activity. The CoMoNiS-NF-31 demonstrates the best electrocatalytic activity, giving ultralow overpotentials (113, 103, and 117 mV for HER and 166, 228, and 405 mV for OER) to achieve a current density of 10 mA cm-2 in alkaline, acidic, and neutral electrolytes, respectively. It also shows a remarkable balance between electrocatalytic activity and stability. Based on the distinguished catalytic performance of CoMoNiS-NF-31 toward HER and OER, we demonstrate a two-electrode electrolyzer performing water electrolysis over a wide pH range, with low cell voltages of 1.54, 1.45, and 1.80 V at 10 mA cm-2 in alkaline, acidic, and neutral media, respectively. First-principles calculations suggest that the high OER activity arises from electron transfer from Co9S8 to MoS2 at the interface, which alters the binding energies of adsorbed species and decreases overpotentials. Our results demonstrate that hierarchical metal sulfides can serve as highly efficient all-pH (pH = 0-14) electrocatalysts for overall water splitting.

Luminescence Tuning of Layered Rare-Earth Hydroxides (LRHs, R = Tb, Y) Composites with 3-Hydroxy-2-naphthoic Acid and Application to the Fluorescent Detection of Al3.

Tunable luminescence (quenching or blue shift) of HNA/OS-LRH composites (HNA is 3-hydroxy-2-naphthoic acid; OS is the anionic surfactant of 1-octanesulfonic acid sodium; LRHs are layered rare-earth hydroxides, R = Tb3+, Y3+) in the solid state and delaminated state is reported, which is utilized as an effective fluorescent probe for detecting metal ions. HNA/OS species are intercalated into LRH layers to generate composites of HNA xOS1- x-LTbH ( x = 0.10, 0.15, 0.20 , 0.25) and HNA yOS1- y-LYH ( y = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30). In the solid state, LYH composites exhibit green emissions (from 493 to 504 nm) with a large blue shift in comparison to the 542 nm emission of free HNA- anions, while in the delaminated state in formamide (FM), the composites display blue emission (480 nm) relative to the green emission (512 nm) of an HNA soltuion in FM. However, LTbH composites display coquenched luminescence in both the solid state and delaminated state. Also, HNA0.25OS0.75-1:1-LYH, HNA0.25OS0.75-1:2-LYH, and HNA0.05OS0.95-1:1-LYH (1:1 and 1:2 are HNA:NaOH molar ratios) show significantly elongated fluorescence lifetimes of 15.35, 14.37, and 12.72 ns, respectively, in comparison with free HNA-Na (6.44 ns), and their quantum yields of 23.40%, 21.97%, and 22.31%, respectively, are much larger than that of free HNA-Na (4.86%). The LTbH composite (HNA0.25OS0.75-1:1-LTbH) has also a relatively higher quantum yield of 12.46%. The HNA0.25OS0.75-1:1-LYH colloid exhibits excellent recognition selectivity for Al3+ over other metal ions (Mg2+, Co2+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2+, and Hg2+) with distinct fluorescence sensitization. It shows an intense change in its fluorescence emission when it is bound to Al3+ ions, giving a lower detection limit of 6.32 × 10-6 M. This is novel research on the fluorescence chemosensing of LRH composites.