Real-time detection of chlorine gas using Ni/Si shell/core nanowires.

Dong-Jin Lee,Byung Yang Lee,Han-Bo-Ram Lee,Kwang Heo,Hochan Chang,Minjun Park,Hyungwoo Lee,Hyungjun Kim,Joon-Hyung Jin

doi:10.1186/s11671-015-0729-2

Abstract

We demonstrate the selective adsorption of Ni/Si shell/core nanowires (Ni-Si NWs) with a Ni outer shell and a Si inner core on molecularly patterned substrates and their application to sensors for the detection of chlorine gas, a toxic halogen gas. The molecularly patterned substrates consisted of polar SiO2 regions and nonpolar regions of self-assembled monolayers of octadecyltrichlorosilane (OTS). The NWs showed selective adsorption on the polar SiO2 regions, avoiding assembly on the nonpolar OTS regions. Utilizing these assembled Ni-Si NWs, we demonstrate a sensor for the detection of chlorine gas. The utilization of Ni-Si NWs resulted in a much larger sensor response of approximately 23% to 5 ppm of chlorine gas compared to bare Ni NWs, due to the increased surface-to-volume ratio of the Ni-Si shell/core structure. We expect that our sensor will be utilized in the future for the real-time detection of halogen gases including chlorine with high sensitivity and fast response.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-015-0729-2) contains supplementary material, which is available to authorized users.

Highlights

Nanoscale hybrid structures of metals and semiconductors have attracted a lot of attention due to their exotic properties [1,2]
We demonstrate the utilization of metal-coated Si NWs with Ni/Si shell/core structures (Ni-Si NWs) as sensor transducers for the detection of chlorine (Cl2) gas, which is a toxic halogen gas
* Correspondence: blee@korea.ac.kr †Equal contributors 1School of Mechanical Engineering, Korea University, 145 Anam-Ro, Seongbuk-Gu, Seoul 136-713, Korea Full list of author information is available at the end of the article work, we introduced a NW with a Ni-Si core/shell structure and demonstrated that a nickel oxide-based structure with high surface-to-volume ratio can be used for the room temperature real-time detection of chlorine gas

Summary

Introduction

Nanoscale hybrid structures of metals and semiconductors have attracted a lot of attention due to their exotic properties [1,2]. Among metal-based materials, nickel and its oxides have been utilized in the detection of ammonia [9,10], glucose [11], and cigarette smoke [12]. We demonstrate the utilization of metal-coated Si NWs with Ni/Si shell/core structures (Ni-Si NWs) as sensor transducers for the detection of chlorine (Cl2) gas, which is a toxic halogen gas. It is worth noting that not much study has been performed on Cl2 gas sensors using nickel oxide materials except for nickel ferrite structure [13], mainly due to its relatively low sensitivity.

Methods

Results

Conclusion