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Magnetic nanoparticle-supported heterogeneous catalysts have been widely researched in green catalysis, due to their convenient magnetic separation and nanometer effects. Herein, a magnetic Co(III)-Salen heterogeneous catalyst with uniform spherical core-shell structure was synthesized for the chemical fixation of CO2 into cyclic carbonate based on the sustainable protocol development and green chemistry principles. Fe3O4@SiO2 nanoparticles with uniform spherical core-shell structure were prepared by the reverse microemulsion method, and Co(III)-Salen complexes were subsequently immobilized on the resulted Fe3O4@SiO2 nanoparticles via covalent bonding, leading to Fe3O4@SiO2@Co(III)-Salen nanocomposites with particle size of 29 nm and saturation magnetization value of 27.2 emu/g. The catalytic performance study indicated that the catalyst exhibited high yield of 99% with selectivity of 100% for the ring-opening addition reaction of CO2 and epoxide under solvent-free reaction condition. A plausible reaction mechanism was proposed that the Lewis acidic sites of Co(III)-Salen and nucleophilic bromine ion components played synergetic roles in promoting cycloaddition reactions. A stable geometry of the Co(III)-Salen complex and a detailed evidence for the reaction mechanism were provided by the density functional theory (DFT) calculations. Based on their excellent magnetic properties, the Co(III)-Salen nanocomposites could be easily recovered by using an external magnet and reused for 5 times without significant leaching of metal center and loss of catalytic activity.

The hydroboration of alkynes is crucial due to the wide applications in organic synthesis, while such reaction is often completed with low turnover frequency (TOF) value and long reaction time. Therefore, it is very important and necessary that the hydroboration of alkynes is performed with high TOF value, however the corresponding investigations have been never reported hitherto. Herein, a new Cu-organic framework 1 with mixed-valence Cu(I) and Cu(II) blocks was successfully synthesized and employed for the hydroboration of alkynes with bis(pinacolato)diboron (B2Pin2). 1 displays good thermostability and excellent solvent stability. Catalytic explorations reveal that 1 can serve as a high efficient heterogeneous catalyst for this reaction with a record TOF value of 310 h−1 under mild conditions, and 1 as catalysts which can be recycled at least five times without adding any cocatalysts. Mechanism investigations suggest that the Cu(I) and Cu(II) clusters in the framework of 1 have a synergistic catalytic effect in the hydroboration of alkynes, which can effectively activate the alkyne to react with B2Pin2. The density functional theory (DFT) calculations explicitly elucidate the reaction pathways, and the results indicate that the Cu(I) and Cu(II) clusters in 1 as the catalytic sites can greatly reduce the Gibbs free energy of the hydroboration of alkyne in different degree, which accounts for the high catalytic activity of 1.

The supported Ni-B/KIT-6 amorphous alloy catalyst was prepared by chemical reduction method for the hydrogenation reaction of α-pinene. The catalyst was characterized by XRD, BET, SEM–EDS, TEM, XPS, ICP and DLS, the influences of single factor of catalyst on its structure, morphology and performance were investigated and analyzed. It was found that the amount of Ni loading, preparation pH and B/Ni molar ratio had great effects on the reduction amount, dispersion and specific surface area of the catalyst, resulted in affecting the catalytic performance of the catalyst. The optimum synthesis conditions were at m(Ni2+)/m(KIT-6) = 1:3, pH 13 and n(B)/n(Ni) = 1.5, obtaining a 90.62% conversion of α-pinene and 97.67% selectivity of cis-pinane. In addition, the catalysts also exhibited better repeatability and stability.

Hollow hydroxyapatite microspheres (HHAM), a type of mesoporous nanomaterials with a specific internal cavity and hierarchical architectures, have attracted enormous interest over the past years owing to their remarkable potential for biomedical applications. However, the as-obtained HHAM fail to meet the need of the ever-updating diagnosis, treatment, and theranostics technologies. With the attempt to enhance performances and expand applications of HHAM, scientists have tailored the properties of HHAM by various methods including -doping modification and surface functionalization to give a versatile type of biomaterials, i.e., functionalized hollow hydroxyapatite microspheres (f-HHAM). Actually, significant achievements in the realm of f-HHAM have been obtained and various intractable clinic problems have been resolved. Nevertheless, designing desirable f-HHAM is expected to accelerate the development of the biomedicine field. In this contribution, the state-of-the-art progress f-HHAM is overviewed, which covers from the developments and preparation methods to bioapplications of these biomaterials. In addition, the current trends and key points as well as the future prospects and challenges for the applications of f-HHAM are discussed, aiming at providing a guideline for rational design of more creative f-HHAM according to different therapeutic requirements.

Although the high energy density of Ni-rich LiNi0.8Co0.15Al0.05O2 (NCA) cathode holds great promise in Li-ion batteries, the moisture sensitivity and undesired dissolution of Ni2+ in electrolytes that causes rapid capacity fading restrict their further commercial applications. Surface coating is an efficient method to address the problems above. Herein, surface modification of the NCA cathode by using a cheap and highly conductive polyacrylonitrile-induced carbon coating is investigated, and molecular dynamics simulation results suggest that the carbon layer should be as thin as possible. In this way, NCA coated with a highly conductive carbon layer of 5 nm in thickness with enhanced cyclability and integral electrochemical performance is made. The coated carbon film also served as a protective layer by shielding the host NCA cathode materials from direct contact with the electrolyte, thus resulting in enhanced electron transfer. During the charge-discharge repeated cycles 100 times, the carbon-coated NCA cathode exhibits an improved capacity retention (98.4%) at a rate of 1 C over pristine NCA (93.1%). The uniform surface coating strategy might serve as an industrial scalable approach to coat a continuous carbon layer on other electrode materials at a relatively low cost.

APO-11 aluminophosphate molecular sieve was prepared by hydrothermal method of aluminum hydroxide with diisopropylamine. Ni–P/APO-11 amorphous alloy catalysts were prepared by chemical reduction method and used for the hydrogenation of α-pinene reaction. The catalysts were characterized by X-Ray photoelectron spectroscopy (XPS), Nitrogen adsorption–desorption isotherms (BET), scanning electron microscope (SEM), transmission electron microscope (TEM) and fourier transform infrared spectrometer (FT-IR).The prepared conditions of the Ni–P/APO-11 catalysts played important roles on the hydrogenation of α-pinene reaction. It was found that the preparation temperature, P/Ni molar ratio and pH value had great influence on the reduction dosage, dispersion and particle sizes of the catalysts, thus affecting the reactivity of the catalysts. The appropriate reaction conditions explored were at 30 °C, n(P/Ni) = 5 and pH = 8, obtaining a 90.65% conversion of α-pinene and 97.87% selectivity to cis-pinane. Under these conditions, the catalysts exhibited better repeatability and stability.

The increasingly severe issue of antibiotic-induced pollution greatly stimulates the development of high-performance advanced adsorbents. In this contribution, a novel Fe-centered metal–organic aerogel (Fe-MOA) was synthesized through the use of bio-based ligand 2,5-furandicarboxylic acid (FDCA). Various characterization techniques including FT-IR, XPS, SEM, TEM, EDX and N2 adsorption–desorption analysis verified the successful preparation of the Fe-MOA with a hierarchically meso and macroporous network structure. The Fe-MOA was subsequently used as an adsorbent for the removal of tetracycline (TC) in aqueous solution. And the results suggested that the Fe-MOA exhibited an unprecedented adsorption capacity for TC with the record value of 1023 mg g−1. The adsorption equilibrium and isotherm data agreed well with the pseudo-second-order and Freundlich models, respectively. The mechanism investigations showed that the ultrahigh adsorption capability was synergistically driven by multiple affinities including electrostatic interaction, hydrogen bonding, surface complexation and π–π interactions between the conjugated groups in TC and the furan rings of the Fe-MOA. The recycling adsorption experiment results showed that the Fe-MOA retained 80% of the 1st-cycle adsorption capacity after being reused for 5 cycles, demonstrating the excellent reusability of Fe-MOA. Compared with other adsorbents, the ultrahigh TC adsorption capacity and excellent recycling performance make the Fe-MOA a favorable adsorbent candidate for TC pollution, highlighting the significant potential for solving practical TC-related pollution issues.

Porous conjugated polymers offer enormous potential for energy storage because of the combined features of pores and extended π-conjugated structures. However, the drawbacks such as low pore volumes and insolubilities of micro- and mesoporous conjugated polymers restrict the loading of electroactive materials and thus energy storage performance. Herein, we report the synthesis of iron-doped macroporous conjugated polymers for hosting sulfur as the cathode of high-performance lithium–sulfur (Li–S) batteries. The macroporous conjugated polymers are synthesized via in situ growth of poly(3-hexylthiophene) (P3HT) from reduced graphene oxide (RGO) sheets, followed by gelation of the composite (RGO-g-P3HT) in p-xylene and freeze-drying. The network structures of the macroporous materials can be readily tuned by controlling the chain length of P3HT grafted to RGO sheets. The large pore volumes of the macroporous RGO-g-P3HT materials (ca. 34 cm3 g–1) make them excellent frameworks for hosting sulfur as cathodes o...

Developing high-performance materials for removal of antibiotics has attracted ever-increasing concerns since variety of harmful antibiotics have been frequently detected in aquatic environments and posed a serious threat to both human health and ecosystems in recent years. In this work, a novel adsorbent (ED-MIL-101) for oxytetracycline antibiotic (OTC) was prepared by grafting ethylenediamine (ED) to Lewis acidic open metal sites in porous metal-organic framework MIL-101. The successful grafting was corroborated via FT-IR spectrum. Compared with the pristine MIL-101, ED-MIL-101 demonstrated a slight decrease in BET surface areas and pore sizes, while the basic frameworks remain invariant. Results for kinetics and thermodynamics showed that the aminofunctionalized adsorbent exhibited a predominant superiority over nongrafted MIL-101 and activated carbon (AC) on the removal of OTC, even though the specific surface area decreased remarkably after grafting. Moreover, ED-MIL-101 can be regenerated by simple washing with ethanol and reusable up to at least the third run with little change in adsorption capacity. Evidence from zeta potential showed that the adsorption of OTC was also driven by electrostatic interaction between the OTC and ED-MIL-101. These results indicate that ED-MIL-101 has great potential in removing OTC contaminant from water.

The overuse of antibiotics triggered a serious environmental crisis, stimulating the development of feasible technologies for removing antibiotics from wastewater. Herein, a set of CeOx@C-TiO2 composites with varying amounts of CeOx from 1% to 15% were synthesized and applied for the photodegradation of tetracycline (TC) for the first time. It was found that the composites exhibited excellent performance for TC removal by degradation and mineralization under visible-light irradiation. The uniform distribution of CeOx nanoparticles in C-TiO2 permitted the surface contact of particles, enhancing their visible light absorption with a reduced band gap of 2.39 eV and electron-transfer efficiency through the formation of heterojunctions. The amount of CeOx played a predominant role in the photocatalytic properties. The 10% composite exhibited high removal rates of 99.1%, 98.2%, and 83.5% for 10, 20, and 40 mg/L TC, respectively. Characterization experiments proved that Ce mainly existed in its +3 and +4 valence states in the composites. The interchange of these two valence states accelerated the transfer of electrons and promoted the production of superoxide anion radicals and hydroxyl radicals responsible for TC degradation. These findings provide valuable guidelines for exploiting high-performance MOF-derived photocatalysts for the abatement of contaminants.

A series of CaO-based sorbents, using low-cost eggshells and red mud (Rm) pretreated by the acid leaching process as raw materials, were synthesized by the dry mixing method. The effects of different sodium leaching ratios, Rm doping contents, and eggshells as calcium precursors on CO 2 capture properties of the CaO-based sorbents are discussed in this paper. The cyclic carbonation/calcination performance of the as-prepared sorbents was evaluated by a thermogravimetric analyzer. The phase compositions and morphologies of the sorbents were characterized by XRD and SEM, respectively. The as-prepared sorbents doped with 10 wt% Rm3 (with a sodium leaching ratio of 99.91%) showed a superior cyclic conversion of 46.67% after 100 carbonation/calcination cycles. The existence of the Ca 12 Al 14 O 33 phase was probably responsible for the excellent CO 2 cyclic performance.

In this work, highly porous MIL-101 materials using hydrochloric acid (HCl) or hydrofluoric acid (HF) as a mineralizer were synthesized. The products were characterized with X-ray diffraction, scanning electron microscopy, thermal gravimetric analysis, and N2 sorption analysis. The results proved that the mineralizers had an obvious effect on the microstructures and morphologies of MIL-101, and MIL-101(HCl) showed remarkable superiority in a higher specific surface area, smaller particle size and higher crystallinity to the HF counterpart. These materials were then used to adsorb and remove the oxytetracycline (OTC) antibiotics from a water solution and an effective fast adsorption of OTC in aqueous solution was observed in the adsorptive kinetics. Compared with MIL-101(HF), a higher adsorption capacity on the MIL-101(HCl) was obtained, which was probably attributed to the higher specific surface area for the MIL-101(HCl). The adsorption mechanism might be greatly ascribed to π–π interaction, and acid–alkaline interaction between the oxytetracycline molecule and the adsorbent.