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Superhydrophobic coatings with intelligent properties have attracted much attention because of their wide application in many fields. However, there is a limited amount of literature on superhydrophobic coatings whose wettability and adhesion can be adjusted by UV irradiation and calcination at the same time. In this study, amorphous SiO2 microspheres (A-SiO2) and nano-TiO2 particles (N-TiO2) were used to fabricate A-SiO2/N-TiO2 composites by wet grinding, and then, they were modified with polydimethylsiloxane (PDMS) and sprayed onto substrate surfaces to obtain a tunable adhesive superhydrophobic A-SiO2/N-TiO2@PDMS coating. It is worth noting that the wettability and adhesion of the coating to water droplets could be adjusted by UV irradiation and calcination. The mechanisms of the aforementioned phenomena were studied. Moreover, methyl orange solution could be degraded by the coating due to its photocatalysis. The as-prepared coating had good adaptation to different substrates and outdoor environments. Moreover, the surfaces of these coatings exhibited the same liquid repellency towards different droplets. This research provides an environmental strategy to prepare advanced self-cleaning coatings. [ABSTRACT FROM AUTHOR]

A series of TiO 2 pillared sericite nanocomposites were prepared by the sol-gel method followed by thermal treatment. Two factors, namely sericite dosage, and calcination temperature were researched to see their effects on the structure and properties of TiO 2 pillared sericite nanocomposite. X-ray diffraction and nitrogen adsorption-desorption isotherms were used to analyze the changes of crystal phase, grain size and pore structure information of the generated TiO 2 nanoparticles in the composite. Among all the samples, the TiO 2 pillared sericite composite calcined at 800 °C has the best photocatalytic properties. Trapping experiment proved that the main active species are ·O 2 −, h+ and ·OH in order of participation during the photodegradation of methyl orange by the prepared composite. Sericite has a synergistic role in enhancing the photocatalytic activity of TiO 2 pillared sericite nanocomposite. Good photocatalytic activity, together with its availability and good recyclability, makes sericite a promising substrate in the field of photocatalysis. • TiO 2 pillared sericite is first time prepared by sol-gel method. • Acetone is chosen as one of the solvents instead of ethanol during the reaction. • The final product has better photocatalytic properties than similar products. [ABSTRACT FROM AUTHOR]

In this paper, SiO 2 -TiO 2 composite particles were prepared by loading nano-TiO 2 onto the surfaces of amorphous SiO 2 microspheres, which were then modified with PDMS to obtain a SiO 2 -TiO 2 @PDMS ternary compound. The photocatalytic performance of SiO 2 -TiO 2 @PDMS and the wettability of the coated surface were tested and characterized. Moreover, the effect of microstructure and composition of SiO 2 -TiO 2 @PDMS on its properties was studied. The results showed that SiO 2 -TiO 2 @PDMS possessed a certain degree of photocatalytic activity and the coating was almost superhydrophobic. Furthermore, the wettability and adhesion to water droplets of the SiO 2 -TiO 2 @PDMS coating were affected by the heat-treatment temperature; the mechanism of the above phenomena was also analysed. Moreover, the as-prepared coating exhibited excellent repellent effects towards acid (pH = 2), alkaline (pH = 11), and organic dye droplets. A mechanically damaged coating maintained its liquid repellence, indicating that the good mechanical stability of the coating. The superhydrophobicity of the as-prepared coating did not decrease after UV irradiation for 8 h, illustrating that the as-prepared coating had a great UV irradiation resistance. In addition, the as-prepared coating was environmentally friendly and free of fluorides and is therefore suitable for practical applications. • A superhydrophobic self-cleaning SiO 2 -TiO 2 @PDMS coating was prepared environmentally without fluorides, toluene and hexane. • The wettability and adhesion to water droplets of the coating surface can be adjusted by different temperatures. • The superhydrophobicity of the as-prepared coating can not be destroyed by UV irradiation. • The as-prepared coating shows the same liquid-repellency toward acid, alkaline, and organic dye droplets. [ABSTRACT FROM AUTHOR]

• The surface of SiO 2 microspheres (MS-SiO 2) carrier is optimized by alkali treatment. • TiO 2 and CdS nanoparticles supported on the optimized surface MS-SiO 2 -0.32 with stronger interaction. • Photogenerated carriers transfer directionally induced by surface hydroxyl group on MS-SiO 2. • The enhanced effect of semiconductor-insulator heterostructure results in the band bend of photocatalyst. Photocatalyst@carrier composites have great potential for the treatment of environment-related issues due to their enhanced photocatalytic activity and increased recovery rate. The surface properties of the carrier could affect the stability and the activity of the nanoparticles and could play a crucial role in the applicability of these nanoparticles. The SiO 2 microspheres (MS-SiO 2) were treated with hot lye to support the UV-activated TiO 2 photocatalyst and visible light-activated CdS photocatalyst. The influence of the surface characteristics of microspheres on the performance and structural peculiarities of the photocatalyst nanoparticles was investigated, with the interactions on the interface between the semiconductor and the carrier. It was found that the activity and the hydroxylation of the surface of MS-SiO 2 were enhanced after alkali treatment, which increased the anchoring sites and the dispersion of the nanoparticles. Moreover, the charge separation and the interface interaction between the semiconductor and the carrier were enhanced, inducing the directional transfer of photogenic carriers. Furthermore, a semiconductor-insulator heterojunction was built between the semiconductor and the carrier, resulting in a change in the band structure of the photocatalyst. This work may provide new considerations for the design of photocatalyst/carrier composites. [ABSTRACT FROM AUTHOR]