Stable surface functionalization of carbonized mesoporous silicon

Abstract

A new method to produce functional surfaces on porous silicon allow long term use of the material in aqueous environments.

Rapid synthesis of nanostructured porous silicon carbide from biogenic silica

“…Bisphosphonate molecules ( Figure 2B) containing protective trimethylsilyl groups (Tetrakis(trimethylsilyl) 1-(trimethylsilyloxy) undec-10-ene-1,1-diylbisphosphonate) were synthesized as described elsewhere. 20 The bisphosphonates were grafted on the PSiC-H650MC by first heating 60 mg of the PSiC powder at 150°C under N 2 atmosphere. The powder was cooled down to room temperature while maintaining the N 2 flow and 120 mg of the bisphosphonate mixed in 5 ml of mesitylene was added to the particles.…”

“…Bisphosphonate molecules (Figure 2B) containing protective trimethylsilyl groups (Tetrakis(trimethylsilyl) 1‐(trimethylsilyloxy) undec‐10‐ene‐1,1‐diylbisphosphonate) were synthesized as described elsewhere 20 . The bisphosphonates were grafted on the PSiC‐H650MC by first heating 60 mg of the PSiC powder at 150°C under N 2 atmosphere.…”

“…In this work, we also demonstrate that the material can be functionalized with suitable organic moieties, such as bisphosphonates. 19,20 Because of its metal adsorbing properties, high surface area, and chemical stability, such material has potential applications, for example, in treatment of wastewater.…”

“…In our previous work, we have shown bisphosphonate-modified nanoporous silicon to be a promising material to be used in metal adsorption. 20,30 It can be surface stabilized by thermal carbonization and used even several tens of cycles. However, the inherent instability and high cost of the nanostructured Si framework are problematic.…”

“…We used the radical addition reaction instead of a more common silanization because it was shown to create a very stable functional layer on carbonized porous silicon with similar surface chemistry with the PSiC. 20 The initial experiments showed a good capability of the material to adsorb lead from a 30 ppm solution and the material could be regenerated with an acid. Further work is ongoing to explore the capabilities of the material in this application in more detail.…”