Fabrication and photocatalytic properties of silicon nanowires by metal-assisted chemical etching: effect of H2O2 concentration

Abstract

In the current study, monocrystalline silicon nanowire arrays (SiNWs) were prepared through a metal-assisted chemical etching method of silicon wafers in an etching solution composed of HF and H2O2. Photoelectric properties of the monocrystalline SiNWs are improved greatly with the formation of the nanostructure on the silicon wafers. By controlling the hydrogen peroxide concentration in the etching solution, SiNWs with different morphologies and surface characteristics are obtained. A reasonable mechanism of the etching process was proposed. Photocatalytic experiment shows that SiNWs prepared by 20% H2O2 etching solution exhibit the best activity in the decomposition of the target organic pollutant, Rhodamine B (RhB), under Xe arc lamp irradiation for its appropriate Si nanowire density with the effect of Si content and contact area of photocatalyst and RhB optimized.

Enhanced photocatalytic degradation of methylene blue by metal-modified silicon nanowires

“…Liu et al used SiNWs elaborated by metal-assisted electroless etching in a solution containing HF/H 2 O 2 as photocatalysts for the photodegradation of Rhodamine B. Different concentrations of H 2 O 2 were experimented and they found that a concentration of 20% gives the best photocatalytic activity; a degradation of 35% was obtained after 5 h of irradiation under Xe arc lamp [9]. Qu et al show that unmodified and Pt-modified porous silicon nanowires can be used as effective photocatalysts for the degradation of organic dyes and toxic pollutants under visible irradiation [10].…”

Silicon Nanowires: Fabrication and Applications

“…Besides the examples given in this chapter, there are many more potential applications like optical devices [142,143], thermoelectric devices [144], catalysts [145] and even more [146]. It is therefore expected that silicon nanowire technology will evolve as a very versatile supplement to the existing silicon technology.…”

Efficient Photocatalysts Made by Uniform Decoration of Cu2O Nanoparticles on Si Nanowire Arrays with Low Visible Reflectivity

“…Silicon nanowires (SiNWs), with good surface hydrophilicity, mechanical robustness, and chemical stability could be the potential supporting materials for strengthening the photocatalytic activity of Cu 2 O nanostructures, rendering a promising design of visible-responsive photocatalysts [8–12]. Moreover, SiNWs further possessed highly visible-absorption capability due to confining the incident lights through the effects of multiple scattering [11].…”