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Highlights: [•] Oxidative decomposition of formaldehyde on Pt/TiO2 occurs at room temperature. [•] Fluoride poisoning phenomenon of Pt/TiO2 nanosheets is explained. [•] This poisoning is due to F-blocking of Pt catalytic active sites. [•] Pt/TiO2 nanosheet-type catalysts can be easily regenerated by washing with NaOH solution. [Copyright &y& Elsevier]

As research continues, the control on the polymorph and morphology of calcium carbonate ( CaCO3) becomes a hot topic because its application is limited by these parameters. The polymorph and morphology control of CaCO3 was successfully achieved via temperature and PEG ( Mw = 6000) during the decomposition of Ca( HCO3)2, which has rarely been employed to prepare precipitated CaCO3. As-prepared CaCO3 was characterized using XRD and SEM. In the case of no PEG, rhombohedra calcite, lamellar vaterite, rod- and needlelike aragonite are observed, and calcite is the major phase at all samples and it increases with temperature, whereas vaterite and aragonite decrease with temperature. The addition of PEG restrains the formation of vaterite and promotes the emergence of needlelike aragonite particles at 70°C, and prevents the generation of calcite and encourages the production of rodlike aragonite particles at 80°C and 90°C. This work not only provides a new way on the preparation of CaCO3 powder but also presents the feasible control method in this route. [ABSTRACT FROM AUTHOR]

As research continues, the control on the polymorph and morphology of calcium carbonate ( CaCO3) becomes a hot topic because its application is limited by these parameters. The polymorph and morphology control of CaCO3 was successfully achieved via temperature and PEG ( Mw = 6000) during the decomposition of Ca( HCO3)2, which has rarely been employed to prepare precipitated CaCO3. As-prepared CaCO3 was characterized using XRD and SEM. In the case of no PEG, rhombohedra calcite, lamellar vaterite, rod- and needlelike aragonite are observed, and calcite is the major phase at all samples and it increases with temperature, whereas vaterite and aragonite decrease with temperature. The addition of PEG restrains the formation of vaterite and promotes the emergence of needlelike aragonite particles at 70°C, and prevents the generation of calcite and encourages the production of rodlike aragonite particles at 80°C and 90°C. This work not only provides a new way on the preparation of CaCO3 powder but also presents the feasible control method in this route. [ABSTRACT FROM AUTHOR]

Hierarchically porous SiO 2 /C hollow microspheres (HPSCHMs) were synthesized by a hydrothermal and NaOH-etching combined route. The adsorption performance of the prepared HPSCHMs was investigated to remove Congo Red (CR) in aqueous solution. The results show that the synthesized composite possesses a hollow microspherical structure with hierarchical pores and a diameter of about 100-200 nm, and its surface area is up to 1154 m 2 g -1 . This material exhibits a remarkable adsorption performance for CR in solution, and its maximum adsorption amount for CR can reach up to 2512 mg g -1 . It shows faster adsorption and much higher adsorption capacity than the commercial AC and γ-Al 2 O 3 samples under the same conditions. The studies of the kinetics and thermodynamics indicate that the adsorption of CR on the PHSCHM sample obeys the pseudo-second order model well and belongs to physisorption. The adsorption activation energy is about 7.72 kJ mol -1 . In view of the hierarchically meso-macroporous structure, large surface area and pore volume, the HPSCHM material could be a promising adsorbent for removal of pollutants, and it could also be used as a catalyst support., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)