"Nanotechnology and nanomaterials"

Silicon nanoparticles preparation and the formation of carbon-silicon hybrid nanoparticles for sensor applications
Mussabek G.1,2, Zhylkybayeva N.1,2, Zaderko A.N.3, Baktygerey S.1,2, 
Yermukhamed D.1,2, Taurbayev Ye.1,2, Lisnyak V.V.1,3
1 Institute of Information and Computational Technologies, Pushkina Str., 125, 050010 Almaty, Kazakhstan. 
2 Al-Farabi Kazakh National University, al-Farabi Ave., 71, 050040 Almaty, Kazakhstan
3 Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, 01601 Kyiv, Ukraine. E-mail: lisnyak@univ.kiev.ua

Preparing silicon nanoparticles (Si NPs) is a problem that needs a nontrivial solution. For this aim, we performed by preparing Si NPs using different routes, including the reduction of silica NPs and silicon-organic compounds and mechanical grinding using porous silicon materials of various origins. Si NPs have developed inner surface and moderate chemical reactivity. The sensitive layer of Si NPs was modified with carbon adatoms by using chemical routs and by carbonization of organic compounds, including sugars, on the surface of Si NPs. We carried these modifications to regulate adsorptive properties for preparing advanced vapor sensors. Prepared by different processes, silicon nanomaterials, in the form of hybrids and composites, were briefly characterized by TEM and SEM methods. We carried out the modification of Si NPs and Si nanoscale filaments with nanocarbon and nanostructured carbon. The formation of hybrids of various types, including the desired ones, in which nanocarbon modifies the nanosilicon surface, occurs because of high-temperature structuring processes. They are passed during the carbonization of carbon-containing precursors. We have developed and successfully applied synthetic techniques for the experimental production of hybrids bound by a thin interface and surface-modified Si NPs. The sensor characteristics of some surface-modified Si NPs were examined with ammonia and alcohol vapors. The obtained nanohybrids with the carbon decorated surface at the interfacial boundaries and the edge defects/oxidized surface of Si NPs showed sensor response towards ammonia in the gas phase being indifferent to low molecular weight alcohols. 
The authors acknowledge financial support from the Ministry of Education and Science of the Republic of Kazakhstan, Grant No. AP08856579.