Currently, designing high-performance structured catalysts is full of significance for economic and sustainable production of chemicals due to the catalysts easy separation and recovery and excellent heat/mass transfer characteristics. Herein, we reported the synthesis of a ternary Co–Ni–Al mixed-metal oxide (CoNiAl-MMO) film with surface intercrossed and vertically aligned nanoplatelets via an in situ growth route. CoNiAl-MMO film exhibited greatly enhanced catalytic performance in the oxidation of benzyl alcohol, compared with binary MAl-MMO films (M = Co or Ni) and pristine CoNiAl-MMO powder. The improved catalytic efficiency was attributable to a synergistic effect between highly dispersed active Co and Ni species, as well as the presence of more surface oxygen vacancies. Moreover, the film possessed extremely high structural stability stemming from the strong interaction between the CoNiAl-MMO layer and the substrate. Such type of structured non-noble-metal film catalyst may have potential industrial applications in a broad range of heterogeneous catalysis systems in the future.

In this work, nitrogen-doped carbon modified MgO–MgFe2O4 (CN-MgFeO) magnetic composites were synthesized by a facile thermal decomposition of Mg–Fe layered double hydroxide (MgFe-LDH) and cyanamide mixture precursors. A series of comprehensive characterization studies including powder X-ray diffraction, transmission electron microscopy, Fourier transform infrared of CO2 adsorption, CO2-temperature programmed desorption, and X-ray photoelectron spectroscopy indicated that the introduction of cyanamide could finely tune the surface basicity of the resulting CN-MgFeO composites, especially surface strong Lewis basicity. Compared with CN-free MgFeO, the as-fabricated CN-MgFeO catalysts showed higher activity in the liquid-phase transesterification of tributyrin with methanol. Particularly, the CN-MgFeO composite prepared at a cyanamide/Mg molar ratio of 1.5 in the synthesis mixture gave a highest methylbutyrate yield of 80% after a reaction for 20 min. The high catalytic performance was attributable to the presence of a large amount of strong Lewis basic sites originating from highly dispersed basic MgO–MgFe2O4 mixed metal oxides and CN component in the composite. What is more, such a cost-effective CN-MgFeO catalyst had the advantages of intrinsic magnetic properties and an excellent structural stability. We expect that they may have potential practical applications in the field of industrial production of biodiesels.

Organic–inorganic hybrid pigments with enhanced thermo- and photostability have been prepared by co-intercalating C.I. Acid Red 337 (AR337) and a UV absorbent (BP-4) into the interlayer of ZnAl layered double hydroxides through a coprecipitation method. The obtained compounds were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric–differential thermogravimetric–differential thermal analysis, UV–visible spectroscopy, and the International Commission on Illumination (CIE) 1976 L*a*b* color scales. The results show the successful co-intercalation of AR337 and BP-4 into the interlayer region of layered double hydroxides (LDHs) and reveal the presence of host–guest interactions between LDH host layers and guest anions of AR337 and BP-4 and guest–guest interactions between AR337 and BP-4. The intercalation can improve the thermostability of AR337 due to the protection of LDH layers. Moreover, the co-intercalation of AR337 and BP-4 not only markedly enhances the photostability of AR337 but also significantly influences the color of the hybrid pigment.Keywords: hybrid pigment; intercalation; layered double hydroxides; photostability; thermostability

NiFe2O4/NiO nanocomposite thin films have been successfully prepared through a facile route using nickel iron layered double hydroxide (NiFe–LDH) as a single-source precursor. This synthetic approach mainly involves the formation of NiFe–LDH film by casting the slurry of NiFe–LDH precursor on the α-Al2O3 substrate, followed by high-temperature calcination. The composition, microstructure and properties of the films were characterized in detail by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and vibrating sample magnetometer (VSM). The results indicate that NiFe2O4/NiO composite film was composed of granules with diameter less than 100 nm, and the thickness of the film was in the range 1–2 μm. The magnetization of the film can be tuned by alternating the Ni/Fe molar ratio of LDH precursor. In addition, the method developed should be easily extended to fabricate other MFe2O4/MO composite film systems with specific applications just by an appropriate combination of divalent/trivalent composition in the precursor of LDHs.

In this work, nitrogen-doped carbon modified MgO–MgFe2O4 (CN-MgFeO) magnetic composites were synthesized by a facile thermal decomposition of Mg–Fe layered double hydroxide (MgFe-LDH) and cyanamide mixture precursors. A series of comprehensive characterization studies including powder X-ray diffraction, transmission electron microscopy, Fourier transform infrared of CO2 adsorption, CO2-temperature programmed desorption, and X-ray photoelectron spectroscopy indicated that the introduction of cyanamide could finely tune the surface basicity of the resulting CN-MgFeO composites, especially surface strong Lewis basicity. Compared with CN-free MgFeO, the as-fabricated CN-MgFeO catalysts showed higher activity in the liquid-phase transesterification of tributyrin with methanol. Particularly, the CN-MgFeO composite prepared at a cyanamide/Mg molar ratio of 1.5 in the synthesis mixture gave a highest methylbutyrate yield of 80% after a reaction for 20 min. The high catalytic performance was attributable to the presence of a large amount of strong Lewis basic sites originating from highly dispersed basic MgO–MgFe2O4 mixed metal oxides and CN component in the composite. What is more, such a cost-effective CN-MgFeO catalyst had the advantages of intrinsic magnetic properties and an excellent structural stability. We expect that they may have potential practical applications in the field of industrial production of biodiesels.