Facile preparation of porous silicon from cost-wise silicon powder as effective catalyst for reduction of p-nitrophenol

Abstract

For the first time, a metalloid is used for the reduction of p-nitrophenol to p-aminophenol. The porous silicon (PS) was prepared via chemical etching technique using HF/HNO3/H2O with a ratio of (1/5/10 v/v) as the chemical etchant. The Si: etchant ratio and etching time was investigated. Higher Si: etchant ratios and longer etching times resulted in an increase in the surface area of the PS. The various PS and silicon powder samples were then tested for the reduction of p-nitrophenol. It was found that the reduction of p-nitrophenol occurs approximately 8 times faster when PS was employed in comparison to silicon. The reduction rates increased with increasing surface area of the PS. Similar trends were observed when the amount of catalyst was added. The PS also shows good reusability for the catalytic reduction of p-nitrophenol.