Silicon nanowires as an efficient material for hydrogen evolution through catalysis: A review

Abstract

Now-a-days use of environment-friendly alternative energy has become a common practice, as the conventional fossil fuel energy is being depleted exponentially. Also, the by-products generated from the fossil fuel have posed serious threat to the environment, which has propelled researchers to find eco-friendly and non-conventional energy sources. Solar, wind, and tidal energies are some of the very common examples of such eco-friendly energy sources. It was not long ago that people realized that hydrogen gas, which has the highest mass-energy density when compared to other fuels, could be used as a clean energy source. Hydrogen can easily be generated by splitting of water through different catalysis reactions i.e., in presence of photon, or electric field or other energy sources. Numbers of catalysts have already been found for large scale hydrogen production that includes noble metals like platinum (Pt), palladium (Pd), etc. However, these noble metals are highly expensive and scarce, which has initiated the search to find low-cost and abundantly available materials for such purpose. Silicon nanowire (SiNWs) is one of such material which has established itself an excellent photo-catalyst for initiation of hydrogen evolution reaction (HER). However, there are few scattered reports showing when SiNW is subjected to electric field it can also initiate HER through electro-catalysis. This review describes some of the basic synthesis scheme and properties of SiNWs along with the application of SiNWs in HER through different catalysis process. The article also highlights a comparative study related to merits and demerits of SiNWs induced electrocatalysis reaction compared to the other existing methods regarding HER.