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The chlorination mechanism of pentlandite with NH4Cl has been proposed. The chlorination of pentlandite can be achieved by two pathways, where O2 plays a crucial role in promoting the chlorination process.

All-inorganic CsPbX3 (X = Cl, Br, I) perovskite quantum dots (QDs) have become a kind of optoelectronic material with huge application prospects due to their excellent physical and optical properties. However, their poor structural stability to the external environment, especially polar solvents, seriously hinder further development in practical applications. Considering whether polar solvents have the same effects on perovskites QDs, few studies have been investigated in this area presently. In order to find out the effect of different polar solvents on all-inorganic perovskite QDs, in this work, we select 12 kinds of polar solvents of methanol, ethanol, isopropanol, 1-butanol, 1-pentanol, 1-octanol, N,N-dimethylformamide (DMF), tetramethylethylenediamine (TMEDA), ethyl acetate, n-butyl acetate, dibutyl phthalate and acetone for a specific analysis. The characterization of their morphology, optical and physicochemical properties shows that different polar solvents have different effects on all-inorganic perovskite QDs, but their effects are regular. Polar solvents act on the ligands preferentially, and the effects can be divided into: reducing the concentration of ligands; substituting ligands partially; completely destroying the surface ligands; polar solvents with the same functional group, as the polarity of the solvent increases, the impact on all-inorganic perovskite QDs is greater. We believe that this discovery has important implications for improving the stability of all-inorganic perovskite QDs.

All-inorganic CsPbX

A facile strategy has been developed to construct unique core–shell-structured Li2.7V2.1(PO4)3 nanocomposites with a Li3V2(PO4)3 core and LiVOPO4 shell by using nonstoichiometric design and high-energy ball milling (HEBM) treatment. The HEBM treatment supplies enough energy to drive the excess V atoms to the surface to form a V-enriched shell. Such kind of cathode can deliver a high reversible capacity of 131.5 mA h g−1 at 0.5C, which is close to the theoretical capacity (133 mA h g−1 in 3.0–4.3 V). Even at 20C, it still delivers an excellent discharge capacity of 116.3 mA h g−1, and a remarkable capacity of 111.0 mA h g−1 after 1000 cycles, corresponding to an ultra-small capacity-loss of 0.0046% per cycle. The significantly improved high-rate electrochemical performance can be attributed to the active shell of LiVOPO4, which not only efficiently facilitates the electron and Li+ ion transport during cycling processes, but also accommodates more Li+ ions to effectively compensate the capacity loss of the core.

Functionalized multiwall carbon nanotubes (MWCNTs) were prepared by coating polyvinylpyrrolidone (PVP) on the MWCNTs surface via multiple hydrogen-bonding interactions between polyvinylpyrrolidone and a mussel-inspired polydopamine (PDA) intermediate. The modified MWCNTs exhibited outstanding dispersity and stability in water and were used as a hydrophilic additive to increase the permeability and antifouling properties of polyethersulfone (PES) ultrafiltration membranes. The results of Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the introduction of PDA and PVP into the MWCNTs. The measured water contact angle of the hybrid membranes revealed dramatically enhanced hydrophilicity. The morphology of the hybrid membranes was investigated by field emission scanning electron microscopy (FESEM). Furthermore, the permeability and antifouling properties of the hybrid membranes when mixed with different types and quantities of MWCNTs were compared. The hybrid membrane containing 0.1% PVP-modified MWCNTs exhibited the best overall performance, including a flux recovery ratio as high as 95%. The facile and universal treatment method developed in the present study can be used to improve the comprehensive performance of membranes, with great potential application in wastewater treatment.

The kinetics, degradation mechanism and degradation pathways of atrazine (ATZ) during sole-UV and UV/H

Phytopathogenic fungi have become a serious threat to the quality of agricultural products, food security and human health globally, necessitating the need to discover new antifungal agents with de novo chemical scaffolds and high efficiency. A series of 8-hydroxyquinoline derivatives were designed and synthesized, and their antifungal activity was evaluated against five phytopathogenic fungi. In vitro assays revealed that most of the tested compounds remarkably impacted the five target fungi and their inhibitory activities were better than that of the positive control azoxystrobin. Compound 2, in particular, exhibited the highest potency among all the tested compounds, with an EC50 of 0.0021, 0.0016, 0.0124, 0.0059 and 0.0120 mM respectively against B. cinerea, S. sclerotiorum, F. graminearum, F. oxysporum and M. oryzae, followed by compound 5c. The morphological observations of optical microscopy and scanning electron microscopy revealed that compounds 2 and 5c caused mycelial abnormalities of S. sclerotiorum. Futhermore, the results of in vivo antifungal activity of compounds 2 and 5c against S. sclerotiorum showed that 5c possessed stronger protective and curative activity than that of 2, and the curative effects of 5c at 40 and 80 μg mL−1 (84.18% and 95.44%) were better than those of azoxystrobin (77.32% and 83.59%). Therefore, compounds 2 and 5c are expected to be novel lead structures for the development of new fungicides.

In order to meet the requirement of high temperature applications, a high thermal stability solid polymer electrolyte is prepared with a poly(aryl ether ketone)–poly(ethylene glycol) copolymer (i.e., PAEK–PEG) as a polymer host, and LiClO4 as an electrolyte salt. A novel flexible solid-state supercapacitor is then assembled by the resultant solid polymer electrolyte and activated carbon electrodes. The electrochemical properties of the supercapacitor are analyzed over a wide temperature range of 30–120 °C. The fabricated supercapacitor has excellent electrochemical performance especially at high temperature (e.g. high specific capacitance of 103.17 F g−1 at 0.1 A g−1 and an energy density of 6.76 W h kg−1 with a power density of 9.55 W kg−1 at 120 °C). Simultaneously, this solid polymer electrolyte based supercapacitor possesses excellent flexible bending properties and outstanding cycle stability of negligible specific capacitance loss after 2000 cycles at various temperatures, demonstrating its feasibility as an energy device for high temperature applications.

Silica tubes with uniform size were designed and prepared by hydrolyzing tetraethyl orthosilicate using D,L-tartaric acid as the self-assembly template. And a novel series of silica tube/poly(aryl ether ketone) composite films were prepared in which silica tubes were covalently bonding onto the side chains of poly(aryl ether ketone) (PAEK-COOH) in the presence of silane coupling agent (γ-aminopropyltriethoxysilane, KH-550). The morphology of the silica tubes was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The chemical structures of the polymer matrix and composites were confirmed by 1H NMR and FT-IR spectra. The patterns of wide-angle X-ray diffraction (WAXD) and X-ray photoelectron spectra (XPS) indicated that the silica tubes were incorporated into the PAEK successfully and the homogeneous dispersion of silica tubes in PAEK was illustrated by scanning electron microscopy (SEM). Furthermore, the impact of silica tubes on the properties of composites was investigated in detail. The composite films exhibited low dielectric constants ranging from 2.22 to 2.57 at 1 MHz owing to the introduction of silica tubes, which was found to be distinctly lower than that of the pristine PAEK-COOH film. Meanwhile, these composites still retained excellent thermal and mechanical properties.

We report on the synthesis of methylammonium tin triiodide (MASnI3) thin films at room temperature by a hybrid thermal evaporation method and their application in fabricating lead (Pb)-free perovskite solar cells. The as-deposited MASnI3 thin films exhibit smooth surfaces, uniform coverage across the entire substrate, and strong crystallographic preferred orientation along the 〈100〉 direction. By incorporating this film with an inverted planar device architecture, our Pb-free perovskite solar cells are able to achieve an open-circuit voltage (Voc) up to 494 mV. The relatively high Voc is mainly ascribed to the excellent surface coverage, the compact morphology, the good stoichiometry control of the MASnI3 thin films, and the effective passivation of the electron-blocking and hole-blocking layers. Our results demonstrate the potential capability of the hybrid evaporation method to prepare high-quality Pb-free MASnI3 perovskite thin films which can be used to fabricate efficient Pb-free perovskite solar cells.

Multi-layer mesoporous TiO2 prepared by screen printing is widely used for fabrication of high-efficiency dye-sensitized solar cells (DSSCs). We compare the three types of ∼10 μm thick mesoporous TiO2 films, which were screen printed as 1-, 2- and 4-layers using the same TiO2 nanocrystal paste. The layer boundary of the multi-layer mesoporous TiO2 films was observed in the cross-section SEM. The existence of a layer boundary could reduce the photoelectron diffusion length with the increase of layer number. However, the photoelectron diffusion lengths of the Z907 dye sensitized solar cells based on these different layered mesoporous TiO2 films are all longer than the film thickness. Consequently, the photovoltaic performance seems to have little dependence on the layer number of the multi-layer TiO2 based DSSCs.

MnO2 nanosheets were successfully grown in situ on the surface of activated carbon fibers (ACFs) via a facile microwave-assisted hydrothermal method. This environmentally-friendly approach displays the advantages of low temperature, short reaction time and low cost. A series of MnO2/ACFs composites with different MnO2 percentages were prepared and their electrochemical performance as an electrode for supercapacitors was investigated. The 63% MnO2 composite showed the optimal charge storage performance, remarkable rate ability, and excellent cycling capability. The enhanced electrochemical performance is attributed to the combination of good electrical conductivity of ACFs and high capacity of MnO2. This work provides a useful insight into the design and fabrication of hierarchical transition metal oxide and carbon material composite electrodes for potential applications in next generation energy storage systems.

A triPEG-boron based solid polymer electrolyte (SPE) membrane is fabricated for all-solid-state lithium ion batteries. With an ether oxygen (EO):LiN(SO2CF3)2 (LiTFSI) molar ratio of 25:1, this electrolyte membrane has ionic conductivities of 2.95 × 10−5 S cm−1 and 1.28 × 10−3 S cm−1, and electrochemical decomposition potentials of 5.23 V and 4.88 V, respectively at 25 °C and 120 °C. The all-solid-state LiFePO4/SPE/Li batteries show high cycling performance in the temperature range of 25–140 °C. At 25 °C and 0.3C, a discharge capacity of 84 mA h g−1 is obtained at the 200th charge–discharge cycle with approximately 100% coulombic efficiency. The batteries also work well at 140 °C and 3C, delivering a discharge capacity of 146 mA h g−1 initially and 113 mA h g−1 after 200 cycles. These results show that this kind of all-solid-state lithium ion battery has a wider working temperature range than conventional liquid electrolyte lithium ion batteries, indicating their suitability for use in fields with high safety requirements.

In this work, polytetrafluoroethylene coating was firstly conducted to make stable and effective magnetic-activated carbon as a heterogeneous electro-Fenton catalyst for diuron oxidation. The catalysts were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). In addition, the effects of operating parameters such as catalyst dosage, current intensity, substrate concentration and pH on the degradation of diuron were investigated. The removal efficiency of diuron was more than 95% within 120 min oxidation under the conditions of I = 100 mA, pH = 6.7 ± 0.2, catalyst loading 3 g L−1 and diuron concentration 10 mg L−1. Moreover, the catalyst durability test demonstrated that the modification of 5% PTFE on the catalyst indeed has a significant beneficial effect on the useful life of the catalyst. We compared the performance of catalysts with or without PTFE modification in consecutive experiments; the modified catalysts exhibited remarkable advantages in that the diuron removal efficiency was stable with relatively low iron leaching (

Decreasing particle size is an efficient strategy for improving the lithium storage properties of Li

This paper describes the synthesis and characterization of a novel series of poly(arylene ether ketone)s bearing porphyrin pendants, along with the demonstration of their nonlinear optical and optical limiting properties at 532 nm in both THF and films. The incorporation of pendant porphyrins was done through a modified esterification using a copoly(arylene ether ketone) with free carboxyl groups and mono-hydroxyphenyl porphyrins with different substituents and center metal. The introduction of porphyrin in the polymer was confirmed by IR, 1H NMR, UV-vis, fluorescence spectroscopies, and WAXD. Investigation of thermal properties indicated that the poly(arylene ether ketone)s with porphyrin pendants possessed higher Tgs, and slightly lower decomposition temperatures than the starting copolymers. The results of optical limiting and Z-scan measurements demonstrated that the porphyrinated poly(arylene ether ketone)s exhibited strong optical limiting responses and nonlinear absorption properties with the nonlinear absorption coefficient β in the order of 10−9 (m W−1) magnitude. The effects of pendant porphyrin structure on the thermal, mechanical, linear and nonlinear optical properties of the poly(arylene ether ketone)s were investigated in detail.

Hollow microspheres of ZnMn2O4 wrapped by graphene have been successfully synthesized via a facile APS aided method. Characterization results certify that the reduced graphene sheets have been wrapped around the hollow ZnMn2O4 microspheres. Charge–discharge testing reveals that ZnMn2O4/RGO delivers superior electrochemical properties in terms of specific capacity, cycle stability (1082 mA h g−1 at 100 mA g−1 after 90 cycles) and high rate capability (580 mA h g−1 at 1 A g−1 after 150 cycles). The improved rate capability and cycling performance of the modified ZnMn2O4 microspheres are attributed to the incorporated RGO sheets’ perfect synergy collaborating with the hollow structures, which can provide higher electronic conductivity, a shorter Li+ diffusion path and also buffer the volume change during Li+ insertion and extraction.

Aligned Ni-NiO core-shell nanowire arrays on a glass substrate were prepared via electrochemical deposition using porous alumina oxide templates. The core-shell nanowire electrodes displayed prominent supercapacitive behaviors. The rate capability of the electrodes depends strongly on the thickness of the NiO shell layers.