Correction for 'Solvothermal synthesis of Co3O4/Al2O3 hollow core–shell microspheres for the catalytic oxidation of CO' by Liangmiao Zhang et al., CrystEngComm, 2014, 16, 6126–6134.

•Mesoporous Co–Al LDHs with rodlike and nanosheet-like morphologies were synthesized via micro-emulsion method.•The calcined Co–Al sample with 10% content of cobalt exhibits the highest specific surface area.•The calcined samples exhibit higher fluoride removal efficiency than the uncalcined ones.•Performance of the adsorption decreases with an increase in the cobalt ratio generally.•The adsorption kinetics and isotherms were also discussed.Facile micro-emulsion methods have been developed to synthesize mesoporous Co–Al hydroxide carbonates with rodlike and hexagonal sheetlike morphologies. A series of samples with different molar ratio of cobalt/aluminum were prepared to investigate the impact of cobalt content. Employing transmission electron microscopy, X-ray diffraction analysis and Fourier transformed infrared spectra, the morphology, structure and composition of the products were investigated. Characterized by gas-sorption measurements, the specific surface area of the calcined S-10 sample with the rodlike morphology was as high as 379 m2/g, which provided this material porosity properties and outstanding fluoride removal efficiency as high as 95.6%. The sorptive removal capacity of fluoride from aqueous solutions by the precursors and their corresponding annealed products was investigated in a batch mode. Also, the adsorption kinetics and isotherms were discussed.

A facile template-free solvothermal strategy has been developed for the synthesis of uniform and hollow core–shell Co3O4/Al2O3 microspheres composed of numerous tiny nanorods. The morphology, structure, and composition of the spheres have been investigated using field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, H2-temperature programmed reduction (H2-TPR) and X-ray diffraction analysis (XRD). The specific surface area and pore-size distribution of the obtained products as determined by gas sorption measurements show that the core–shell microspheres exhibit a high surface area and porosity. The formation of the hollow structure involves a trisodium citrate (TSC)-assisted Ostwald ripening process. The structure and factors that govern the shape evolution of the core–shell Co3O4/Al2O3 microspheres have been carefully studied, such as the Co wt% content, the TSC/Al ratio and the temperature. The catalytic activity of the as-prepared core–shell Co3O4/Al2O3 microspheres has been evaluated for CO catalytic oxidation. Their high performance may be attributed to their large specific surface area, high porosity and mesoporous structure.

Core–shell Al2O3-supported nickel catalyst was prepared and the products were tested in fixed-bed reactor for biomass tar steam reforming. In our work, toluene is treated as tar destruction model compound. The products were characterized by the means of H2-TPR, XRD, BET, TEM and SEM. Comparing with the nanoparticles alumina-supported counterparts, the catalyst showed not only superior activity, more yields of outgases but also better stability. The stable shells provide the unique environment around active sites and the strong interaction between Ni and the core–shell supports seems to be responsible for the catalyst activity and stability in toluene steam reforming. The methods presented in this work can be generalized in materials design and control synthesis of other nano materials.

Well-defined porous Co3O4 nanodendrites have been synthesized by a simple one-pot hydrothermal method combined with subsequent calcination. Importantly, after thermal treatment, the dendritic morphology could be completely preserved. The as-obtained superstructures are characterized by several techniques, such as powder X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoemission spectroscopy, elemental analysis, transmission electron microscopy, high-resolution TEM and magnetometry. On the dendritic hierarchical structures, a number of nanorods with different lengths and widths are connected to the main trunk with a diameter of about 50 nm and length of several micrometers. Each branch is about 0.5–1.0 μm with a width ranging from 100 to 400 nm. The possible formation mechanism was proposed on the basis of the contrasting experiments. It demonstrated that trisodium citrate and acetone play important roles in the synthesis of Co3O4 nanodendrites, while the other reaction parameters, such as reaction temperature, concentration of trisodium citrate and reaction time, have close relationships with the final morphology of the Co3O4 products. Optical properties of Co3O4 nanodendrites were characterized by Raman and UV-vis spectroscopy. Magnetic property measurement shows that Co3O4 nanodendrites have a low Néel transition temperature of 35 K. The as-prepared mesoporous Co3O4 nanostructures are expected to have great applications in many fields.

The AlOOH core/shell microspheres were successfully synthesized via a one-step template-free hydrothermal route. By simply changing the ratio of alcohol to water, core/shell microspheres constructed with nanoplatelets and their curling structures could be selectively synthesized. A series of controlled experiments have also been carried out to better understand the formation mechanism of AlOOH spheres and the function of reactants used in the experiments. The formation of core/shell structures may involve aggregation of amorphous building clusters into spheres and their subsequent reaction, dissolution, and re-deposition process. The morphology, structure, and composition of the spheres are investigated using field-emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analysis. The specific surface area and pore-size distribution of the obtained product as determined by gas-sorption measurements show that the boehmite core–shell microspheres exhibit high Brunauer–Emmett–Teller (BET) surface area and porosity properties. The as-prepared AlOOH core–shell superstructures are powerful in the removal of Congo red pollutant from waste water.