Scalable synthesis of mesoporous titania microspheres via spray-drying method

Mesoporous TiO2 has several potential applications due to its unique electronic and optical properties, although its structures and morphologies are typically difficult to tune because of its uncontrollable and fast sol-gel reaction. In this study we have coupled the template-directed-sol-gel-chemistry with the low-cost, scalable, and environmentally benign aerosol (spray-drying) one-pot preparation technique for the fabrication of hierarchically mesoporous TiO2 microspheres and Fe3O4@mesoporous TiO2−x microspheres in a large scale. Parameters during the pre-hydrolysis and spray-drying treatment were varied to successfully control the bead diameter, morphology, monodispersity, surface area and pore size for improving their effectiveness for better application. Unlike to the previous aerosol synthetic approaches, where mainly quite a high temperature gradient with the strict control of spray-drying precursor concentration is implied, our strategy is lying on comparatively low drying temperature with an additional post-ultrasonication (further hydrolysis and condensation) route of the pre-calcined TiO2 samples. As-synthesized mesoporous microspheres have a size distribution from 500 nm to 5 μm, specific surface areas ranging from 150 to 162 m2 g−1 and mean pore sizes of several nanometers (4–6 nm). Further Fe3O4@mesoporous TiO2−x microspheres were observed to show remarkable selective phosphopeptide-enrichment activity which might have significant importance in disease diagnosis and other biomedical applications.This work was supported by the State Key Basic Research Program of the PRC ( 2012CB224805 and 2013CB934104 ), Shanghai Sci. & Tech. Committee ( 14JC1400700 ), Shanghai Science and Technology Commission ( 14JC1400700 ), NSF of China (Grant 21210004 , 51422202 , 51372041 , U1463206 ), the Shu Guang Project ( 13SG02 ), the State Key Laboratory of Pollution Control and Resource Reuse Foundation ( PCRRF12001 ), National Youth Top Talent Support Program of National High-level Personnel of Special Support Program (Youth Top-notch Talent Support Program), State Key Laboratory of ASIC & System ( 2015KF002 ), Qatar University grant # QUUG-CAS-DMST-15 ? 16-18 . The authors extend their sincere appreciations to the Deanship of Scientific Research at King Saud University for its funding this Prolific Research group ( PRG-1437-32 ). MP acknowledges China Postdoctoral Science Foundation for postdoctoral fellowship.Scopu