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Converting waste biomass into biochar is a means for solving both environmental pollution and energy shortage. Here we transformed Eichhornia crassipes, a harmful floating plant, into a honeycomb-shaped and heteroatoms-rich biochar by KOH activation during carbonization, and we tested this biochar as anode for lithium-ion batteries. Results show that the biochar has a high surface area of 278.56 m2·g−1, a honeycomb-like porous structure, and is rich in heteroatoms, e.g., 3.42% N, 20.82% O, and 0.83% S. Biochar anodes displayed a higher initial reversible specific capacity of 697 mAh·g−1 at 50 mA·g−1, a higher rate capability of 229.7 mAh·g−1 at 3000 mA·g−1, and a better cyclic stability than commercial graphite. The enhanced electrochemical performance could be attributed to the interconnected porous structure that promotes Li+ transfer and electrolyte infiltration, and to the presence of heteroatoms. This approach can be easily industrialized as a substitute of graphite.

Ultraviolet radiation (UVR) and noise are the ubiquitous environmental hazards with considerable detrimental effects on the physiological and psychological health of humans. Exploiting efficient protective materials that can be extensively used in daily life for simultaneous anti-UVR and noise mitigation will be of crucial importance, but it is still a significant challenge in materials design. Herein, we developed a series of protective textiles for efficient anti-UVR and noise reduction via MOFs nanocrystal-modified cotton textiles. The formation of MOFs@cotton textiles was confirmed by using electron microscopy, X-ray diffraction, infrared spectroscopy, and X-ray photoelectron spectroscopy. The fabricated MOFs@cotton textiles exhibited substantial improvement in the UVR blocking and acoustic absorption properties compared to blank cotton textiles. Therefore, this work provides a good strategy for designing and preparing multifunctional protective textiles.

Two heptanuclear discs, [Co7 (L1)6 (CH3 O)6 ]2+ (Co7 -L1) and [Co7 (L2)12 ](ClO4 )2 (Co7 -L2), have been prepared by the reaction of [Co(H2 O)6 ](ClO4 )2 with Schiff base HL1 (HL1=2-methoxy-6-[(methylimino)methyl]phenolate) or benzimidazole derivative HL2 (HL2=(1H-benzo[d]imidazol-2-yl)methanolate), respectively, at room temperature. In contrast, the reaction of [Co(H2 O)6 ](ClO4 )2 with a mixture of the two ligands, having similar coordination ability but different shapes, resulted in the butterfly-structured tetranuclear cobalt cluster [Co4 (L1)2 (L2)4 ](ClO4 )2 ⋅2H2 O (Co4 ). Electrospray ionization mass spectrometry (ESI-MS) analysis in real time revealed the {Co1 }→{Co2 }→{Co4 }→{Co7 } stepwise assembly when a single ligand was employed, but when both ligands were used only {Co4 } was obtained, an intermediate of the former reactions. Interestingly, ligand competition was evidenced in the assembly process of the reaction with two ligands; for example, [Co4 (L1)4 (L2)2 ]2+ and [Co4 (L1)3 (L2)3 ]2+ were the primary clusters observed at the beginning of the reaction, but [Co4 (L1)2 (L2)4 ]2+ was the final product. This observation suggests ligand exchange is taking place, and DFT calculations confirmed that these transformations were possible. By varying the ratio of ligands, the abundance of a certain species in the competitive reaction could be controlled.

The conjugation of bridging bis(diphenylphosphine oxide) alkane or arene ligands was found to control the structural dimensionality and the emission color of complexes from reactions with SmIII(hfac)3(H2O)2 (hfac− = hexafluoroacetylacetonato) while retaining the Sm⋯Sm distances. Bis(diphenylphosphine oxide)-1,4-butane (L1) affords a one-dimensional (1D) ribbon {Sm(hfac)3(L1)}∞ (1) that emits red color, while bis(diphenyl-phosphinoyl)-1,4-benzene (L2) results in a two-dimensional (2D) network {Sm(hfac)2(CF3COO)(L2)3}∞ (2) and near-white emission, but bis(diphenyl-phosphinoyl)-9,10-anthracene (L3) forms a zero-dimensional (0D) cyclic structure {Sm(hfac)3(L3)}2 (3) with strong π⋯π interactions that emit green color. Noticeably, the conjugation change is accompanied by a configurational change of coordination from trans for 1 and 2 to cis for 3. The color change is associated with the superposition of ligand and Sm based electronic band energies and their intensities. Such white light emission by a single compound having contributions from different building components is quite rare.

Using a facile one-step hydrothermal method, a series of metal-organic frameworks containing Gd/Tm (Gd/Tm-MOFs) were prepared successfully. Through the mutual activation of Gd3+ and Tm3+, Gd/Tm-MOFs showed unexpected excellent up-conversion luminescence (UCL) and a superior positive magnetic resonance image (MRI). Using doxorubicin hydrochloride (DOX) as a drug model, the feasibility of Gd/Tm-MOFs as a multifunctional drug carrier was demonstrated. Through modifying Gd/Tm-MOFs with uniform mesoporous silica (mSiO2) shells and folic acid (FA), the drug loading was improved up to 41.5 mg g-1, and pH responsive drug release increased to 64% from 12% by regulating the pH from 5.8 to 7.4. Also, the particles were tracked by MRI, and the second highest longitudinal relaxivity (r1) among the reported gadolinium complexes of 225.86 mM-1 s-1 was achieved. The cell imaging shows obvious blue and red luminescence under 980 nm laser excitation, and the up-conversion luminescence is unique because there is no autofluorescence from cells under 980 nm excitation. This indicates their promising application in the biological field. All the experiments indicate the promising application of Gd/Tm-MOFs in diagnosis and treatment.

A one-dimensional manganese(II) complex, [Mn(L2)]n (1, HL = 4-pyridyl-NH-1,2,3-triazole), has been hydrothermally synthesized at 120 °C. In the structure of 1, the Mn(II) ions are octahedral coordinated and further bridged by L− ligands, forming a rigid 1D ribbon coordination chain. Varieties of supramolecular interactions, such as hydrogen bonds and C H ⋯ π interactions, play an important role on the stabilization of the structures. As revealed by magnetic measurement, complex 1 displays weak antiferromagnetic interaction with θ = –4.83 K, the best fit using Fisher's 1D Heisenberg model gives the intrachain magnetic coupling constant J = –0.21 cm− 1 above 30 K due to the neighboring Mn(N–N)2Mn rings twisted in the angle of almost 90°.

The bond order and packing ratios in the single-crystal of the two structural polymorphs as well as the detailed electronic structures of the molecular model were studied using density functional theory. The strength of different Mn coordination bonds was analyzed in detail through Mayer bond order. Besides bond length, many other factors such as the orientation of ligand and nature of metal also significantly influence the bond order. Packing ratios calculated using cluster model reveals that packing along b direction in Dimer is more favorable than other directions due to the associated interactions of π-π and Cl…H when packing in this direction. Electronic structure helps explain the formation of Dimer from monomer or direct forming of Chain from ligand/Cl and metal. This would shed light on further understanding the importance of supramolecular interaction on crystal engineering.

Sorption is widely used for the removal of toxic heavy metals such as hexavalent chromium (Cr(VI)) from aqueous solutions. Green sorbents prepared from biomass are attractive, because they leverage the value of waste biomass and reduce the overall cost of water treatment. In this study, we fabricated biochar (BC) adsorbent from the biomass of water hyacinth (Eichhornia crassipes), an invasive species in many river channels. Pristine BC was further modified with nanoscale zero-valent iron (nZVI) and stabilized with chitosan (C) to form C&ndash, nZVI&ndash, BC. C&ndash, BC adsorbent showed high hexavalent chromium sorption capacity (82.2 mg/g) at pH 2 and removed 97.34% of 50 mg/L Cr(VI) from aqueous solutions. The sorption capacity of chitosan&ndash, nZVI-modified biochar decreased while increasing the solution pH value and ionic strength. The results of a sorption test indicated that multiple mechanisms accounted for Cr(VI) removal by C&ndash, BC, including complexation, precipitation, electrostatic interactions, and reduction. Our study suggests a way of adding value to biomass waste by considering environmental treatment purposes.

Analyses of the structural information of molecular fragments from the mass spectra of the solid-state products and their reaction solutions allow for the understanding of their formation and of their diverse properties. The reaction of CuCl2 and (1-methyl-1H-benzo[d]imidazole-2-yl)methanol (HL) led only to crystals containing molecular dimers of [Cu2(L)2Cl2] (Cu2). The CuII–CuII distance and Cu–OR–Cu angle in the structure are 3.044 A and 104.8°, respectively. The magnetic susceptibility (3–400 K) is characterized by a very strong intradimer antiferromagnetic interaction of J = −465 and interdimer zj = −0.83 cm−1. But mass spectrometry of a dissolved single crystal in different source energies identifies both its fragmentation and oligomerization to [CuII3] and [CuII4]. DFT calculations give the relative stabilization energies of the fragments observed in ESI-MS to provide a formation process.

Cobalt oxide and porous carbon materials are desirable catalysts for peroxymonosulfate (PMS) advanced oxidation reaction in the degradation of organic pollutants. Herein, carbon-coated Co3O4 (Co3O4/C) mounted biochar (BC) composites (Co3O4/C-BC) with a three-dimensional spongy-like network were constructed by driving a dual-precursors of zeolitic imidazolate framework (ZIF-67) and Eichhornia crassipes. Considering the unique structures and compositions, the Co3O4/C-BC composites enhanced the dispersion of Co3O4/C nanoparticles, minimized the Co leaching, mediated the size of Co3O4/C nanoparticles, and enhanced the overall catalytic activity. Co3O4/C-BC effectively activated PMS for bisphenol A (BPA) degradation along with satisfactory reusability in advanced oxidation reaction. Electron paramagnetic resonance and radical quenching tests revealed that the generation and effect of sulfate and hydroxyl radicals in reaction process. This work not only provided a promising catalyst for the degradation of organic pollutants but also expanded BPA degradation pathway and PMS activation mechanism.

Functionalized biochar as a great potential purification material towards removal of contaminants form environment. Herein, Fe2O3/TiO2 functionalized biochar (Fe2O3/TiO2-BC) was fabricated through one-step pyrolysis of Fe2+–Ti4+ laden tea leaves biomass under air environment. The morphology, structure, and chemical state of Fe2O3/TiO2-BC were systematically characterized. Fe2O3/TiO2-BC exhibits higher degradation efficiency for dye pollutants via synergistic effect of sorption and oxidation in the Fenton system. The total organic carbon (TOC) removal efficiencies reached above 65 %. The degradation mechanisms and pathways of dyes (methylene blue (MB) selected as model), and the effects of the amount of H2O2, catalyst dosage, temperature, and initial pH value on the degradation processes were also studied. The electron spin resonance (ESR) and radicals quenching experimental results confirmed that the dominant radical species was hydroxyl radical. Additionally, Fe2O3/TiO2-BC could be easily regenerated by washing with water/ethanol mixture. Overall, these results indicate that the Fe2O3/TiO2-BC provides great potential for removing dye pollutants from water.

The present study aimed to evaluate the effect of fluoride (F) on spermatogenesis in male rats. F− at 50 and 100 mg/L was administered for 70 days, after which the testicular and epididymis tissues were collected to observe the histopathological structure under a light microscope. The ultrastructure of the testis and sperm was also examined via transmission electron microscopy. The apoptosis of spermatogenic cells was measured through terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The expression of proliferation factors, namely, proliferating cell nuclear antigen (PCNA) and Ki-67, in the testicular and epididymis tissues, were assayed through immunohistochemistry. F− at 50 and 100 mg/L significantly damaged the structure of the testis and epididymis, and the testis and sperm ultrastructure exhibited various changes, including mitochondrial swelling and vacuolization, and apsilated and raised sperm membrane. F treatment significantly increased spermatogenic cell apoptosis in the testis. PCNA (P

The newly synthesized ionic triple salt Ru–Er, {[RuII(bpy)2(dbim)][ErIII(hfac)4][CF3COO]·H2O} (bpy = 2,2′-bipyridine; hfac− = hexafluoroacetylacetonate; dbim = 2,2′-dibenzimidazole) exhibits near-infrared (NIR) emission at 1535 nm by intermolecular Ru → Er (d → f) energy transfer across supramolecular interactions when pumped within the Ru(II) 3MLCT band. It is the first such observation for a transition metal–lanthanide ionic pair.

A clear dependence on the ligand has been observed for the magnetic properties of a closely related series of Co(II) cubane structures, viz. [Co4(mbm or bm)4(ROH)4Br4] (1-MeOH, 1-EtOH, 2-MeOH, and 2-EtOH, where 1 = [Co4(mbm)4Br4], 2 = [Co4(bm)4Br4], bm = (1H-benzo[d]imidazol-2-yl)methanolate. and mbm = 1-Me-bm.) The [Co4(OR)4] cubane core consists of an octahedral CoII center chelated by the alkoxide oxygen and imidazole nitrogen atoms from monoanionic bm or mbm and coordinated by methanol/alcohol and bromine. Interestingly, electrospray ionization mass spectrometry (ESI-MS) indicates that 1-MeOH and 2-MeOH are unstable in methanol and transformed to the butterfly [Co4L6]2+ but that 1-EtOH and 2-EtOH are stable in ethanol. Their magnetic susceptibilities suggest ferromagnetic coupling between the nearest cobalt centers to give a theoretical S = 4 × 3/2 ground state with considerable magneto-crystalline behavior. The packing and intermolecular interactions appear to influence the geometry of the cubes and ...

Herein, quasi-square planar CuII(Hmbm)Cl2 (CBC, Hmbm = (1-methyl-1H-benzo[d]imidazol-2-yl)methanol) was arranged in a pseudo orthogonal way to form Cl-bridged chains, and further ππ interactions resulted in distorted hexagonal layers. DFT calculations reveal a bond strength order of Cu-Cl > Cu-O/N ≫ CuCl. ESI-MS data reveal several small fragments from CBC, but oligomeric [Cu], [Cu], and [Cu] for non-zero in-source energies; MS data indicates the occurrence of several chemical processes, viz. splitting of the ligand, oligomerization, and redox reaction of alcohol to aldehyde and CuII to CuI. Gibbs free energies for the fragments were estimated using DFT. The magnetic susceptibility was modeled with the ferromagnetic coupling J(Cu-Cl2aCu) = +0.99(30) cm-1 and J'(ππ) = +0.35(16) cm-1 and g = 2.38(2). HF-EPR determined the anisotropic g-values, gx = 2.24, gy = 2.16, and gz = 2.09, and a hyperfine constant of Az = 450 G. DFT calculations from crystal structure data reveal a J(Cu-Cl2aCu) of +3.6 at 296 K and +4.1 cm-1 at 90 K that dominates the magnetic properties, whereas J'(ππ) = 0.04 cm-1 is negligibly small.