Residual Metal Impurity Aids Facile In Situ Electrochemical Surface Derivatization of Single‐Walled Carbon Nanotubes

Abstract

Residual metal impurities were exploited as reactants in the functionalization of the surface of single-walled carbon nanotubes (SWCNT) with nickel hexacyanoferrate (NiHCF) by simple electrochemical cycling in ferricyanide solutions. This facile in situ electrochemical modification process provides intimate contact between NiHCF and SWCNTs that improves the stability of the redox property and reactivity of NiHCF. The characteristic redox behavior of NiHCF on SWCNT surfaces can be used as an electrochemical probe to access qualitative and quantitative information on unknown electroactive metal impurities in SWCNTs. Significantly, the NiHCF-modified SWCNTs exhibit pseudocapacitive behavior, and the calculated specific capacitances are 710 and 36 F g(-1) for NiHCF-SWCNTs and SWCNTs respectively. Furthermore, NiHCF-SWCNTs were transformed into Ni(OH)2 /SWCNTs and used for enzymeless glucose oxidation.

Stable and Sensitive Amperometric Determination of Endocrine Disruptor Bisphenol A at Residual Metal Impurities Within SWCNT

“…Our group has also reported that the presence of residual metal impurities in SWCNTs act as an active site for selective deposition of ZnHCF on SWCNT modified GCE , which shows enhanced pseudo‐capacitance property. In addition, the same residual impurity in SWCNT leads in‐situ formation of NiHCF and Ni(OH) 2 /NiOOH composite on SWCNT when simple electrochemical cycling in alkaline solution and shows the high pseudo‐capacitance as well as enzyme‐less glucose oxidation .…”

“…The detailed characterization of SWCNT using ICP‐MS and TEM has been discussed in our earlier reports . As received SWCNTs have several metal impurities such as Ni (8.7 %), Fe (4.5 %) and Zn (7 %) based on ICP‐MS analysis and the morphology of these metal impurities in SWCNTs were further confirmed by TEM analysis.…”