Surface Characteristics and Catalytic Activity of Copper Deposited Porous Silicon Powder.

Muhammad Halim,Mohamad Bakar,Noor Bakar,Wei Tan

doi:10.3390/ma7127737

Abstract

Porous structured silicon or porous silicon (PS) powder was prepared by chemical etching of silicon powder in an etchant solution of HF: HNO3: H2O (1:3:5 v/v). An immersion time of 4 min was sufficient for depositing Cu metal from an aqueous solution of CuSO4 in the presence of HF. Scanning electron microscopy (SEM) analysis revealed that the Cu particles aggregated upon an increase in metal content from 3.3 wt% to 9.8 wt%. H2-temperature programmed reduction (H2-TPR) profiles reveal that re-oxidation of the Cu particles occurs after deposition. Furthermore, the profiles denote the existence of various sizes of Cu metal on the PS. The Cu-PS powders show excellent catalytic reduction on the p-nitrophenol regardless of the Cu loadings.

Highlights

Porous silicon (PS) was discovered more than 50 years ago; the interest of the scientific community on PS was only triggered in recent years
Porous silicon powder was prepared via chemical etching, other techniques, such as metal-assisted chemical etching [14,15] and electrochemical etching [16], have been reported to produce
The technique employed in this work is attractive, because of its simplicity and the presence of readily available oxidizing and corrosive reagents; namely nitric acid (HNO3) and water (H2O), as well as hydrogen fluoride (HF)

Summary

Introduction

Porous silicon (PS) was discovered more than 50 years ago; the interest of the scientific community on PS was only triggered in recent years. Among its most significant characteristics are its very large specific area, which can reach up to. PS has been incorporated with biological molecules, because it allows the loading of large quantities of such materials. Devices that can be deposited in humans without undesirable reactions can be developed [1]. PS is widely used in electronic and optic devices [2]. This illustrates the technological benefits of PS in specific applications

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Results

Conclusion