TiO₂-coated wollastonite composite pigments were prepared by the mechano-chemical grinding of wollastonite and TiO₂ powder together in a wet ultrafine stirred mill. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and infrared spectra were used to investigate the microstructures and morphologies of the composite and the reaction mechanism. The results indicate that the TiO₂-coated wollastonite composite pigments have similar properties to titanium dioxide pigment, showing much better properties than dry and wet mixing of wollastonite and TiO₂. The hiding power of TiO₂-coated wollastonite composite pigments (45% TiO₂) is 17.97 g/m², reaching 81.08% of titanium dioxide. A firm combination between wollastonite and TiO₂ is obtained through a surface dehydroxylation reaction during the mechano-chemical method.

CaCO₃-TiO₂ composite particles were prepared with calcium carbonate (CaCO₃) and TiO₂ in stirred mill according the wet grinding method. The pigment properties, morphology, and structure of CaCO₃-TiO₂ composite particles and the interaction behaviors between CaCO₃ and TiO₂ particles were explored. In the CaCO₃-TiO₂ composite particles, TiO₂ is uniformly coated on the surface of CaCO₃ and the firm combination between CaCO₃ and TiO₂ particles is induced by the dehydration reaction of surface hydroxyl groups. CaCO₃-TiO₂ composite particles have similar pigment properties to pure TiO₂. The hiding power, oil absorption, whiteness and ultraviolet light absorption of composite particles are close to those of pure TiO₂. The application performance of CaCO₃-TiO₂ composite particles in the paint is consonant with their pigment properties. The contrast ratio of the exterior paint containing CaCO₃-TiO₂ composite particles is equivalent to that of the paint containing the same proportion of pure TiO₂.

Eu²⁺, Eu³⁺ and Mn⁴⁺ co-doped Sr₄Al₁₄O₂₅ phosphors were synthesized in air by high temperature solid-state reaction.

The critical need to enhance the quality of indoor air leads to the improvement of catalyst activity for the removal of formaldehyde. Sepiolite can be utilized in catalytic reactions for its unique structure, composition and high surface area. The adhesion between sepiolite fibers and the blocked microporous channel (by impurities) demands the activation of natural sepiolite through acid treatment. This treatment successfully produces acid-modified sepiolite Pt-supported samples. The impacts of different acid concentrations, Pt loading content and calcination temperature on catalytic activity for formaldehyde (HCHO) oxidation are studied. The catalytic activity of HCHO is characterized and evaluated by techniques including specific surface area, X-ray diffraction, Fourier transform infrared spectrum, X-ray photoelectron spectroscopy and transmission electron microscopy. The results show the maximum specific area of sepiolite at the optimized 0.06 M acid concentration. Among all the prepared samples, the 0.02Pt/Sep catalyst calcined at 500 °C exhibits the highest catalytic activity for the oxidation of HCHO.