Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2012-01-30

Journal: JOURNAL OF HAZARDOUS MATERIALS

Included Journals: PubMed、EI、SCIE

Volume: 201

Page Number: 155-161

ISSN: 0304-3894

Key Words: Optical sensor; HMS; Heavy metal ions; 4-(2-Pyridylazo)-resorcinol

Abstract: A novel and low-cost optical sensor for heavy metal ion detection has been prepared by immobilizing 4-(2-pyridylazo)-resorcinol (PAR) on the functionalized hexagonal mesoporous silica (HMS) via N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (TMAC). The successful fabrication of this optical sensor is confirmed by extensive characterizations using FT-IR, low angle X-ray diffraction (XRD), UV-vis spectroscopy and N-2 sorption, meanwhile its colorimetric properties, selectivity, sensitivity and reversibility are also investigated. The optical sensor responds selectively to heavy metal ions, such as Fe3+, Cd2+, Ni2+, Zn2+, Pb2+, Co2+, Hg2+ and Cu2+ with a color change from yellow to orange or purple in alkaline solutions, while it shows a color change only for Cu2+ under strongly acidic conditions. At pH 12.0, this optical sensor has a high sensitivity that makes it possible to detect Cu2+ in aqueous solution with the detection limit as low as 40 ppb by naked-eye. This optical sensor also shows excellent reversibility and regeneration by treatment with a solution of EDTA. (C) 2011 Elsevier B.V. All rights reserved.