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Volatile methyl siloxanes (VMS), which are considered to be the most troublesome impurities in current biogas-cleaning technologies, need to be removed. In this study, we fabricated a series of Fe3O4–urea-modified reduced graphene-oxide aerogels (Fe3O4–urea–rGOAs) by using industrial-grade graphene oxide as the raw material. A fixed-bed dynamic adsorption setup was built, and the adsorption properties of the Fe3O4–urea–rGOAs for hexamethyldisiloxane (L2, as a VMS model pollutant) were studied. The properties of the as-prepared samples were investigated by employing various characterization techniques (SEM, TEM, FTIR, XRD, Raman spectroscopy, and N2 adsorption/desorption techniques). The results showed that the Fe3O4–urea–rGOA–0.4 had a high specific surface area (188 m2 g−1), large porous texture (0.77 cm3 g−1), and the theoretical maximum adsorption capacity for L2 (146.5 mg g−1). The adsorption capacity considerably increased with a decrease in the bed temperature of the adsorbents, as well as with an increase in the inlet concentration of L2. More importantly, the spent Fe3O4–urea–rGOA adsorbent could be readily regenerated and showed an excellent adsorption performance. Thus, the proposed Fe3O4–urea–rGOAs are promising adsorbents for removing the VMS in biogas. [ABSTRACT FROM AUTHOR]

A unique method of preparing TiO2/sericite composite particles material was investigated by coating anatase TiO2 on the surface of sericite via chemical precipitation method. The results of X-ray diffraction, scanning electron microscope, infrared spectra and X-ray photoelectron spectroscopy indicated that TiO2 coated uniformly on the surface of sericite, and Si-O-Ti chemical bonds are formed during the thermal treatment process. The hiding power of Ti/SE-CPM composite is up to 85% of TiO2 white pigments, and the oil absorption value was equal to TiO2 white pigments. All these data demonstrated that the obtained Ti/SE-CPM samples have similar excellent properties compared with anatase TiO2 white pigments. Therefore, this study provides a feasible way of reducing the usage of TiO2 while maintaining similar pigment properties, which, of course, will reduce the cost, protect our environment and has a potential application in large-scale production of white pigments. [ABSTRACT FROM AUTHOR]

The work obtained mesoporous TiO 2 white pigments using titanyl sulfate as titanium source with a simple, low-temperature method simplifying the synthesis process and reducing the energy consumption. We investigated the effects of the aging temperature and aging time on the structure and pigments properties of the samples. The structure and morphology of mesoporous samples were characterized by X-ray diffraction and transmission electron microscopy. The obtained mesoporous TiO 2 showed excellent pigments properties of whiteness (93.91%), hiding power (12.37 g m −2 ), and lightness value (97.89), respectively. Moreover, such materials showed outstanding photodegradation performance of organic dyes under UV light irradiation. The current research provided an alternative route to prepare mesoporous TiO 2 micspheres white pigments with well photocatalytic performance for indoor purification on industrial scale. It has great significance in titania white pigments field. [ABSTRACT FROM AUTHOR]