Indoor organic gaseous pollution is a global health problem, which seriously threats the health and life of human all over the world. Hence, it is important to fabricate new sensing materials with high sensitivity and efficiency for indoor volatile organic compounds. In this study, a series of ordered mesoporous silica-based nanocomposites with uniform carbon coatings on the internal surface of silica mesopore channels were synthesized through a simple template–carbonization strategy. The obtained mesoporous silica–carbon nanocomposites not only possess ordered mesostructures, high surface areas (up to ∼759 m2 g−1), large and tunable pore sizes (2.6–10.2 nm), but also have the improved hydrophobicity and anti–interference capability to environmental humidity. The sensing performances of the mesoporous silica–carbon nanocomposites to volatile organic compounds, such as ethylbenzene, methylbenzene, benzene, methanol, acetone, formaldehyde, dichloromethane and tetrahydrofuran, were systematically investigated. The relationships between the sensing performances and their properties, including mesostructures, surface areas, pore sizes, carbon contents and surface hydrophilic/hydrophobic interactions, have been achieved. The mesoporous silica–carbon nanocomposites with hexagonal mesostructure exhibit outstanding performance at room temperature to benzene and acetone with high responses, short response (2–3 s) and recovery (16–19 s) time, strong anti–interference to environmental humidity, and long–term stability (less than ∼5% loss of the frequency shifts after 42 days). Therefore, the obtained mesoporous silica–carbon nanocomposites have a hopeful prospect in the field of environmental air quality monitoring.

In this paper, we report a facile one-pot route to prepare core-shell Ag2S@MSN mesoporous silica nanospheres with near-infrared (NIR) photoluminescent properties. The Ag2S@MSN nanospheres have uniform core-shell structures with single monoclinic α-Ag2S nanocrystal core (∼17 nm), ordered mesoporous silica shell (the thickness of ∼20 nm), very high surface area (∼909 m2 g−1), and uniform pore size (∼2.6 nm). The core-shell Ag2S@MSN nanospheres show NIR emission at around 1275 nm excited by a 648 nm laser diode, which can be observed in a wide range of concentration (0.2∼3.2 mg mL−1). The stability of the NIR photoluminescence for the core-shell Ag2S@MSN nanospheres is greatly improved compared to the bare Ag2S nanocrystals. The NIR emission intensity could be enhanced after the hydrothermal treatment with the increase of crystallinity of the silver sulfide cores. The thickness of mesoporous silica shell could be tuned by adjusting the amount of silica source. Furthermore, the core-shell Ag2S@MSN nanocomposites with several small Ag2S nanoparticles in one mesoporous silica shell could also be obtained, which may be a good candidate for bioimaging and biolabeling.

Transparent ordered mesostructured resin-silica composite monoliths with uniform rectangular shape which fully copies the inner-shape of vessels and size (5 × 3 × 0.3 cm3) are prepared via a facile approach of evaporation induced self-assembly (EISA) without adding any protecting agent by using triblock copolymer Pluronic F127 as a template. Ordered mesoporous carbon-silica composite monoliths can be obtained in a wide range of silica content (34–82 wt %) after calcination in N2. Monolithic shape can be maintained with shrinkage (∼20%) in sizes. Furthermore, each component of the composites can be easily removed after the simple post treatments. After etching silica, mesoporous carbon monoliths retain the same in shape and sizes, but show much larger pore volume (∼2.65 cm3/g) and higher surface area (∼1800 m2/g) than the carbon–silica composites. Besides, mesoporous silica monoliths with large pore size (∼14.6 nm) show an integral and uniform shape after air combustion. The obtained mesoporous carbon monoliths show high capacitance (186 F/g) and high cycling stability (8% capacitance loss after 1000 cycles), exhibiting an excellent potential in capacitor applications.Keywords: carbon; composite; crack-free; electrochemistry; mesoporous; monolith;

The uniform core–shell silver nanoparticle@mesoporous silica nanospheres have been prepared by a simple one-pot synchronous method, which combines several steps into one, including the generation of silver nanocrystals and mesoporous silica, transfer and aggregation of silver nanoparticles in an incompact silica framework.

Hierarchically porous silica materials have been synthesized through a confinement self-assembly approach in the skeletal scaffolds of commercial polyurethane (PU) foams. Macroporous/mesoporous silica materials with a well-ordered two-dimensional (2-D) hexagonal (p6mm) mesostructure have been synthesized in an acidic solution using tetraethoxysilane as a precursor, triblock copolymer Pluronic P123 as a mesostructural template, and PU foams with three-dimensional (3-D) interconnecting strut networks as a macrostructure scaffold. By controlling the volume ratio of the cast silica sol to the PU foam scaffolds, hierarchically porous silica monoliths with various macropore structures can be obtained. The porous silica monoliths can be disassembled into uniform polyhedron-like particles. The porous silica polyhedrons exhibit macropores 100−500 μm in diameter, adjustable uniform mesopores (6.5−9.3 nm in diameter), high surface areas (340−780 m2/g), and large pore volumes (0.48−1.16 cm3/g). The resulting macroporous/mesoporous silica polyhedrons show an excellent adsorption and remove capability of Microcystin-LR in wastewater.

The hydrothermal stability of mesostructured cellular silica foams (MCFs) was studied in detail for the first time, using a variety of techniques including transmission electron microscopy, nitrogen sorption, small-angle X-ray scattering, 29Si solid-state nuclear magnetic resonance, and Fourier transform infrared spectroscopy. It was found that the high aging temperature, greater microporosity, and high calcination temperature contribute to the stability of MCFs in high-temperature steam. The frameworks of MCFs calcined at 550 °C are stable in 100% steam at 600 °C for 12 h, but cannot withstand more critical conditions of 800 °C steam and collapse completely. By elevating the calcination temperature of MCFs to 900 °C, the polymerization degree of the silica frameworks is further enhanced, and the obtained MCF materials exhibit high hydrothermal stability under steam at 800 °C for 12 h. The results indicate that increasing the calcination temperature is an effective method to improve the hydrothermal stability of MCFs. It is concluded that 3-D disordered MCFs show structural variations during the high-temperature steam treatments different from those of 2-D ordered hexagonal SBA-15 materials. The pore size, window size, and wall thickness were unaltered for the steam-treated MCFs, while the pore size decreased and the pore wall thickness became thicker for SBA-15.

A simple strategy for the synthesis of macro-mesoporous carbonaceous monolith materials has been demonstrated through an organic-organic self-assembly at the interface of an organic scaffold such as polyurethane (PU) foam. Hierarchically porous carbonaceous monoliths with cubic (Im\( \bar 3 \)m) or hexagonal (p6mm) mesostructure were prepared through evaporation induced self-assembly of the mesostructure on the three-dimensional (3-D) interconnecting struts of the PU foam scaffold. The preparation was carried out by using phenol/formaldehyde resol as a carbon precursor, triblock copolymer F127 as a template for the mesostructure and PU foam as a sacrificial monolithic scaffold. Their hierarchical pore system was macroscopically fabricated with cable-like mesostructured carbonaceous struts. The carbonaceous monoliths exhibit macropores of diameter 100–450 μm, adjustable uniform mesopores (3.8–7.5 nm), high surface areas (200–870 m2/g), and large pore volumes (0.17–0.58) cm3/g. Compared with the corresponding evaporation induced self-assembly (EISA) process on a planar substrate, this facile process is a time-saving, labor-saving, space-saving, and highly efficient pathway for mass production of ordered mesoporous materials.

Mesoporous tungsten titanium oxides (MTTO) materials have been synthesized by using triblock copolymer (EO106PO70EO106, Pluronic F127) as a structure-directing agent via “acid–base pairs” strategy. Two different inorganic precursors, tungsten chloride (WCl6) and titanium isopropoxide [Ti(OPr)4], were used as the “acid–base pair”. The calcined MTTO materials have been investigated by using XRD, TEM, N2 adsorption–desorption isotherms and UV-DRS techniques. The XRD and TEM results show that MTTO materials have well-defined two-dimensional (2D) hexagonal mesostructure. The N2 adsorption–desorption isotherm of the MTTO materials shows that the products have a pore size of 9.8 nm, a pore volume of 0.29 cm3 g−1 and a BET surface area of 150 m2 g−1. The UV-DRS spectrum for the MTTO materials reveals that the materials possess maximum absorption at 340 nm. Such materials have been utilized as matrix to detect the peptide (Gramicidin S) by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The results show that the signal intensities of the MALDI-MS spectrum for Gramicidin S with the MTTO materials as matrix are about hundredfold of those obtained with nonporous WO3–TiO2 as matrix.

Ordered large-pore (up to 12 nm) and stable mesoporous aluminophosphates (AlPO) have been synthesized by using block copolymer (EO106PO70EO106, Pluronic F127) as a structure-directing agent. The selection of inorganic precursors is based on an “acid–base pair” route. Three acid–base pair, including AlCl3/H3PO4, AlCl3/OP(OCH3)3 and Al(OC4H9)3/PCl3 are confirmed to be efficient for the assembly of periodic mesoporous frameworks. Ordered 2-D hexagonal mesoporous aluminophosphates can be obtained by using AlCl3/H3PO4 as precursors, while disordered mesoporous aluminophosphates are produced by using AlCl3/OP(OCH3)3 or Al(OC4H9)3/PCl3 as precursors. BET surface areas and pore sizes of the products vary from 261 to 115 m2/g and from 9.4 to 12 nm, respectively. The solution and solid state 27Al and 31P MAS NMR were used to characterize the chemical environment of aluminium and phosphorus before and after the formation of mesostructured AlPO products, which simultaneously allows us to evaluate the efficiency of inorganic–inorganic (I–I) interactions (Al–O–P) of different acid–base pair. Both 27Al and 31P MAS NMR results show that among the three acid–base pair, AlCl3/H3PO4 pair interacts more readily with each other than the other two pairs [AlCl3/OP(OCH3)3, Al(OC4H9)3/PCl3], and tends to form rigid framework before calcination. The detailed structural characterizations reveal that strong I–I interactions (Al–O–P) between inorganic precursors will lead to a final mesoporous material with high structure regularity. This method can also be applied to synthesize iron-incorporated aluminophosphate (FeAlPO) with highly ordered 2-D hexagonal structure. BET surface area and pore size of FeAlPO prepared with Fe/Al=0.1 (molar ratio) are 181 m2/g and 8.9 nm, respectively. Electron spin resonance (ESR) and UV–vis spectra were employed to characterize the chemical state of Fe3+ ion.

The uniform core–shell silver nanoparticle@mesoporous silica nanospheres have been prepared by a simple one-pot synchronous method, which combines several steps into one, including the generation of silver nanocrystals and mesoporous silica, transfer and aggregation of silver nanoparticles in an incompact silica framework.

In this paper, we report a facile one-pot route to prepare core-shell Ag2S@MSN mesoporous silica nanospheres with near-infrared (NIR) photoluminescent properties. The Ag2S@MSN nanospheres have uniform core-shell structures with single monoclinic α-Ag2S nanocrystal core (∼17 nm), ordered mesoporous silica shell (the thickness of ∼20 nm), very high surface area (∼909 m2 g−1), and uniform pore size (∼2.6 nm). The core-shell Ag2S@MSN nanospheres show NIR emission at around 1275 nm excited by a 648 nm laser diode, which can be observed in a wide range of concentration (0.2∼3.2 mg mL−1). The stability of the NIR photoluminescence for the core-shell Ag2S@MSN nanospheres is greatly improved compared to the bare Ag2S nanocrystals. The NIR emission intensity could be enhanced after the hydrothermal treatment with the increase of crystallinity of the silver sulfide cores. The thickness of mesoporous silica shell could be tuned by adjusting the amount of silica source. Furthermore, the core-shell Ag2S@MSN nanocomposites with several small Ag2S nanoparticles in one mesoporous silica shell could also be obtained, which may be a good candidate for bioimaging and biolabeling.