Guibin Ma

Saline–alkali soil is common in north China, especially in the Datong district in north Shanxi province. Improving the soil will benefit the environment and society. Graphene oxide (GO) has been shown to benefit agricultural and forest soils. Herein, we explore three different experimental conditions of CK (CK means irrigated with tap water), CJ (CJ means 0.2 g of bacteria addition and irrigated with tap water), and CJ25 (CJ25 means 0.2 g of composited bacteria plus 25.0 mg/L of GO added and irrigated with tap water) for saline–alkali soil by the addition of optimized amounts of GO and external bacteria. Our results show that the addition of 25.0 mg/L GO and microbial agents increases the number of bacteria and fungi in the soil and improves the species abundance of bacteria and fungi in the saline–alkali soil, while having little effect on species richness. The GO and bacterial treatment increased the abundance of Proteobacteria, Actinobacteriota, Chloroflexi, Pseudomonas, Ascomycota, Mortierella, and Fusarium. These bacteria have been shown to produce proteolytic enzymes and cellulases that decompose lignin and cellulose in litter, and thus play important roles in carbon and nutrient cycling. The addition of GO and microorganisms provides a viable way to improve saline–alkali soils.

The poly(methacrylic acid) (PMAA) polymer stabilized silver nanoclusters Ag_n (n = 2-9), synthesized in aqueous solution by the selected light wavelength irradiation photolysis approach, have been functionalized with thiol and amine ligands and successfully transferred from aqueous to organic media. Low- or high-resolution positive mass spectra showed constant species composites with the molecular formula Ag_nL_n-1 [n = 2 to ∼9, L = butylmercaptan (C₄H₉S), thiolphenol (C₆H₅S), or dodecanethiol (C₁₂H₂₅S)] and proved that the molecules consist of deprotonated sulfur ligands in each species with one positive charge. Fourier transform infrared and X-ray photoelectron spectroscopy are consistent, indicating deprotonated sulfur, while silver has a zero valence value. The composition of the functionalized silver clusters is in agreement with that observed from polymer-wrapped "naked" silver clusters, which strongly indicates their real existence. For the silver cluster amine systems (heptylamine, dodecylamine, and oleylamine), only "naked" silver cluster species were detected from mass spectroscopy, similar to the polymer-wrapped case, indicating they are not stable enough in the gas phase. The development of a new antibacterial mask material is very important. The dodecylamine-capping silver nanoclusters were selected by coating the coffee filter surface to conduct antibacterial tests with Staphylococcus aureus and Escherichia coli, demonstrating very efficient antimicrobial properties even with organic capping ligands. Experiments also show that they work on mask material. One nanowire assembly with polystyrene and dodecylamine-capping silver nanoclusters was prepared, showing uniform nanofibers generated via the electrospray technique.

Superhydrophobic materials, particularly those with high thermal stability, are critically important. Traditional polymer‐based superhydrophobic materials are not sufficiently stable to work at relatively high temperatures. Herein we have developed a facile approach to synthesize superhydrophobic inorganic ceramics by silane chemical functionalization to metal oxide nanowires to form metal‐oxygen‐silicon chemical bonds via a silane vapor coating technique. The very high thermally stable superhydrophobic materials have generated and can maintain a superhydrophobic surface at temperatures as high as 390 °C, 490 °C and 500 °C for K _2‐x Mn ₈ O ₁₆ , ZnO and TiO ₂ metal oxide nanowires, respectively. Once the temperature point is exceeded, the superhydrophobic surface becomes superhydrophilic and but can be switched back to superhydrophobic by a silane vapor coat, indicating a reversible surface property.

Treating [Ru(PPh₃)₃Cl₂] with the amine 2-picolylamine (Picam) ligand in a 1:1 molar ratio, the Ru(II) complex trans-Ru(PPh₃)₂(Picam)Cl₂ (1) is obtained in methylene chloride and can be isolated as a pure solid compound. The single-crystal structure of 1 was determined by X-ray crystallography. The geometry at the Ru metal center is a distorted octahedral environment with a trans arrangement of the two chlorides. A trans effect of the bond lengths was observed within the structure. Similarly, treating [Ru(PPh₃)₃Cl₂] with 1:1:1 molar ratios of 2-picolylamine (Picam) and 1,1′-bis(diphenylphosphine)ferrocene (DPPF) ligands yielded the Ru(II) complex trans-Ru(DPPF)(Picam)Cl₂ (2). In identical conditions, the homogeneous hydrogen transfer catalytic reactivity of complexes 1 and 2 has been tested in a basic 2-propanol solution and they indicate different catalytic activity. It was discovered that monodentate and bidentate phosphine ligands of Ru(II) complexes, as well as cis- and trans-chloro configuration display different catalytic properties from our experimental data, in agreement with literature data. Based on DFT calculations, the relative molecular catalytic reactivity of all available experimental data is understood from the relative calculated molecular energy.

Three oxygen donor gallium(III) halide complexes, [GaX₃(O=P(TMP)₃] (TMP = trimethoxylphenyl and X = Cl⁻ (1), Br⁻ (2) and I⁻ (3)), are prepared by oxidation in mixed solvents from their phosphine adducts of [GaX₃(P(TMP)₃]. Three crystalline compounds are obtained from the solutions and their crystal structures are determined in the solid state. It is rare to generate a crystalline phase for metal–adduct compounds of this bulky ligand; in this paper, three new crystal structures are presented.

Solid‐state NMR analysis on wurtzite alloyed CdSe_1−xS_xcrystalline nanoparticles and nanobelts provides evidence that the¹¹³Cd NMR chemical shift is not affected by the varying sizes of nanoparticles, but is sensitive to the S/Se anion molar ratios. A linear correlation is observed between¹¹³Cd NMR chemical shifts and the sulfur component for the alloyed CdSe_1−xS_x(0Cd=169.71⋅X_S+529.21). Based on this correlation, a rapid and applied approach has been developed to determine the composition of the alloyed nanoscalar materials utilizing¹¹³Cd NMR spectroscopy. The observed results from this system confirm that one can use¹¹³Cd NMR spectroscopy not only to determine the composition but also the phase separation of nanomaterial semiconductors without destruction of the sample structures. In addition, some observed correlations are discussed in detail.

Graphene sheets were prepared by calcination of calcium carbonate with plant leaves under the protection of an argon gas atmosphere. This is an environmentally friendly approach to produce graphene. Calcium carbonate decomposes with the evolution of carbon dioxide at high temperature, which is reduced into graphene by the magnesium from plant leaves. The formation mechanism of graphene is discussed in detail. The synthesized graphene sheets were characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), and Raman spectroscopy. Calcium carbonate and plant leaves are readily available and inexpensive natural resources, and this new methodology can be applied for large‐scale graphene production in industry.

Size-control of species via wavelength to selectively synthesize Ag quantum clusters (QCs) was utilized and the synthesis conditions of this system (AgNO3, poly(methacrylic acid) (PMAA) with light) were optimized by changing a variety of parameters. Silver QCs, stabilized by PMAA with different compositions, have been synthesized in aqueous solution by tuning the irradiation monochromatic light wavelengths (300 nm or 365 nm) and AgNO3/MAA ratio (1 or 2). The novel preparation procedure has demonstrated a new approach to enlarge the population of Ag QC family and proved the effectiveness of size-control to prepare Ag QCs by tuning the light wavelength. Naked Ag QC species Agn (n= 2-9, 11 and 13) in polymer matrices are fully characterized by mass spectrometer, thus providing finger-printing evidence of their presence. Details regarding the photolysis reaction procedure, Ag QC optical properties and the origins of fluorescence are discussed. Through a combination of results obtained from mass spectroscopy, fluorescence and TDDFT (time-dependent density functional theory), we can assign the origin of fluorescence from a small silver cluster of Ag2 in organic scaffolds. The kinetics of the photolysis reaction follows first-order kinetics (k = 0.1/h). After thiolphenol (C6H5S) ligand functionalization of the generated silver clusters in aqueous solution, the low or high resolution mass spectra showed the constant species composites with a molecular formula AgnLn-1 (n = 2 ∼ 9). More evidence indicated the formation of polymer-wrapped silver clusters. Their anti-bio property was explored, and we confirmed that they indeed show efficient activity.