A series of visible-light-driven mesoporous structured MnO(2)/TiO(2) nanocrystal photocatalysts have been synthesized through a modified sol-gel method, and the N(2) adsorption-desorption isotherm confirms that the mesoporous materials possess large pore size (up to 9.2 nm) and a narrow pore size distribution. X-ray powder diffraction (XRD) analyses and complementary x-ray photoelectron spectroscopy (XPS) measurements reveal that the doping of the transition metal Mn inhibits the growth of TiO(2) anatase nanocrystals and the Mn species are highly dispersed on the surface of TiO(2). The ultraviolet (UV)-vis spectrum demonstrates the excellent adsorption properties of MnO(2)/TiO(2) over the whole region of visible light, which enables this novel photocatalysis material to possess remarkable activity in the photocatalytic degradation of methylene blue under visible light radiation. Moreover, a 'coating mechanism' based on the nucleation of titania nanocrystals along with the interaction between the dopant precursors and titania clusters has been suggested.

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A novel Zn2+-sensitive fluorescent chemosensor SC/SBA-15 has been obtained by the self-assembly of 4-chloroaniline-N-salicylidene (SC), a Schiff base ligand, within the channel of silylation-modified SBA-15 without destroying its hexagonally ordered mesoporous structure. The remarkable 200-fold fluorescence enhancement with a large Stokes shift of 180 nm in luminescence emission upon the addition of Zn2+ is attributed to the formation of a coordinate complex of a large rigid conjugate system and Zn2+ ions.

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A novel hybrid mesoporous material PMBA-SBA was designed and synthesized by immobilizing bis-schiff base N,N‘-(1,4-phenylenedimethyli- dyne)bis(1,4-benzenediamine) (PMBA) within the channels of (γ-chloropropyl)triethoxysilicane (CPTES) modified SBA-15. TEM images of the hybrid materials illustrated the reservation of the hexagonal ordered mesoporous structure of SBA-15 after functionalization. The characteristic absorbance of the CN stretching vibration of the Schiff base was observed in the IR spectrum of the hybrid materials, indicating the successful immobilization of PMBA in the mesoporous composite, while the XPS spectra confirmed that the linkage of the PMBA molecule within the channels of CPTES-functionalized SBA-15 is realized by forming a covalent bond between amino and chloropropyl groups. This novel mesoporous material PMBA-SBA showed a high selectivity to Fe3+ ion, which results from a dramatic fluorescence quenching by the addition of Fe3+ ion upon the suspensions of PMBA-SBA. A good linearity between the fluorescence intensity of PMBA-SBA and the concentration of Fe3+ ion is constructed, which enables this hybrid martial as a fluorescence chemosensor for detecting the Fe3+ ion with a satisfactory detection limit of 1.98 × 10-6 M. Judged on the linear equation, the fluorescence quenching of the hybrid material by Fe3+ ion progresses by static quenching forming a nonfluorescence complex.

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