Mesoporous silica based recyclable probe for colorimetric detection and separation of ppb level Hg2+ from aqueous medium

Abstract

Functional mesoporous silica probes, MCM-TFM and SBA-TFM, have been synthesized with varying pore sizes and having S-donor sites judiciously selected to bind soft metal centers. The soft S-donor centers are contributed by the thiol functional groups that are introduced into the silica matrices by functionalization with tris(4-formylphenyl)amine followed by 2-aminothiophenol. The materials rapidly and selectively detect Hg2+ colorimetrically and the change in color profile can be perceived through bare eyes. The probes can decontaminate the pollutant heavy metal from aqueous medium at ppb level and the materials are recyclable and reusable for several separation cycles.

Morphology Controlled Synthesis of Heteroatom-Doped Spherical Porous Carbon Particles Retaining High Specific Capacitance at High Current Density

“…When the temperature is increased to 800 °C for CPSM-800, the surface area increases drastically to 622 m 2 •g −1 (Figure 2c) and the isotherm again shows type IV nature with a hysteresis loop between P/P 0 values of 0.35 to 0.80, indicating the formation of mesopores in the sample. 49 On increasing the temperature of pyrolysis further to 900 °C, the surface area increases further to 712 m 2 •g −1 for CPSM-900, but the natures of the isotherms change (Figure 2d) somewhat. When the temperature is further raised to 1000 °C, the surface area does not increase substantially with the nature of the isotherms remaining almost similar (Figure 2e).…”

Modulating the Sensing Behavior of Functionalized Mesoporous Silica towards Metal Ions in Aqueous Medium

“…It has been obtained by step‐wise functionalization of a mesoporous silica support synthesized by a reported procedure [37] . The SBA‐15 type of silica support is at first activated by grafting amine groups on its surface through 3‐aminopropyltriethoxysilane (3‐APTES) to give material ( I ) [17] . The derivative of bisphenol A, 5,5′‐(propane‐2,2‐diyl)bis(2‐hydroxybenzaldehyde ( Compound A ) [38] and rhodamine 6G, N‐(rhodamine‐6G)lactam‐ethylenediamine ( Compound B ) [39] have been synthesized following reported procedures (Scheme S1).…”

“…[37] The SBA-15 type of silica support is at first activated by grafting amine groups on its surface through 3-aminopropyltriethoxysilane (3-APTES) to give material (I). [17] The derivative of bisphenol A, 5,5'-(propane-2,2-diyl)bis(2-hydroxybenzaldehyde (Compound A) [38] and rhodamine 6G, N-(rhodamine-6G)lactamethylenediamine (Compound B) [39] have been synthesized following reported procedures (Scheme S1). Material (I) on reaction with Compound A gives material (II) through Schiffbase reaction between the amine group of 3-APTES anchored on the solid support and one aldehyde group of Compound A, leaving behind one aldehyde moiety for further reaction.…”

“…Due to the heterogeneous nature of these materials, they can be easily separated by filtration. Thus, in certain cases mesoporous silica based sensors can not only be employed for sensing, but they can also be used for the purpose of separation [17] . However, it depends much on the nature of the host‐guest interaction between the probe and the analyte which determines the actual mechanism of the sensing properties displayed.…”

SBA-15 with Crystalline Walls Produced via Thermal Treatment with the Alkali and Alkali Earth Metal Ions

“…Mesoporous silica like MCM-and SBA-series is a very interesting material in the field of nanotechnology [1,2] and has been prepared by the templating method using surfactants and/or polymers as templates, have tunable pore sizes and mesostructures and high surface areas [1][2][3][4][5][6]. Mesoporous silicas can be applied in catalysis [7][8][9][10], sorption [11][12][13][14][15][16][17][18], separations [19][20][21][22][23][24], drug delivery [25][26][27][28][29][30], optics [31,32], sensing [33][34][35], devices [36] and imaging [37,38].…”