title: Synthesis of Bismuth-Nanoparticle-Enriched Nanoporous Carbon on Graphene for Efficient Electrochemical Analysis of Heavy-Metal Ions.
abstract: A BiNPs@NPCGS nanocomposite was designed for highly efficient detection of multiple heavy-metal ions by in situ synthesis of bismuth-nanoparticle (BiNP)-enriched nanoporous carbon (NPS) on graphene sheet (GS). The NPCGS was prepared by pyrolysis of zeolitic imidazolate framework-8 (ZIF-8) nanocrystals deposited on graphene oxide and displayed a high surface area of 1251 m(2)  g(-1) and a pore size of 3.4 nm. BiNPs were deposited on NPCGS in situ by chemical reduction of Bi(3+) with NaBH4 . Due to the restrictive effect of the pore/surface structure of NPCGS, the BiNPs were uniform and well dispersed on the NPCGS. The BiNPs@NPCGS showed good conductivity and high effective area, and the presence of BiNPs allowed it to act as an efficient material for anodic-stripping voltammetric detection of heavy-metal ions. Under optimized conditions, the BiNPs@NPCGS-based sensor could simultaneously determine Pb(2+) and Cd(2+) with detection limits of 3.2 and 4.1 nM, respectively. Moreover, the proposed sensor could also differentiate Tl(+) from Pb(2+) and Cd(2+). Owing to its advantages of simple preparation, environmental friendliness, high surface area, and fast electron-transfer ability, BiNPs@NPCGS showed promise for practical application in sensing heavy-metal ions.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (P. R. China), Fax: (+86) 25-8359-3593.
authors.forename: Lin
authors.initials: L
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (P. R. China), Fax: (+86) 25-8359-3593.
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (P. R. China), Fax: (+86) 25-8359-3593. hxju@nju.edu.cn.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
keywords: bismuth; electrochemistry; nanostructures; voltammetry; zeolite analogues