One‐Dimensional Carbon Nanotube/SnO 2 /Noble Metal Nanoparticle Hybrid Nanostructure: Synthesis, Characterization, and Electrochemical Sensing

Herein we report a facile and efficient method for self‐assembling noble‐metal nanoparticles (NPs) to the surface of SnO 2 ‐coated carbon nanotubes (CNT@SnO 2 ) to construct CNT@SnO 2 /noble metal NP hybrids. By using SnCl 4 as the precursor of the SnO 2 shell on the surface of CNTs, the hydrolysis speed of SnCl 4 was slowed down in ethanol containing a trace amount of urea and water. The coaxial nanostructure of CNT@SnO 2 was confirmed by using X‐ray powder diffraction (XRD) and transmission electron microscopy (TEM). It was found that the coating layer of SnO 2 was homogeneous with the mean thickness of 8 nm. The CNT@SnO 2 /noble‐metal NP hybrids were obtained by mixing noble‐metal NPs with as‐prepared CNT@SnO 2 coaxial nanocables by means of a self‐assembly strategy. With the amino group terminated, the CNT@SnO 2 coaxial nanocable can readily adsorb the as‐prepared noble‐metal NPs (Au, Ag, AuPt, and AuPd NPs). The presence of an amino group at the surface of SnO 2 was proved by use of X‐ray photoelectron spectroscopy (XPS). In addition , H 2 O 2 sensing by amperometric methods could serve as detection models for investigating the electrocatalytic ability of as‐prepared hybrid materials . It was found that wide linear ranges and low detection limits were obtained by using the enzyme‐free CNT@SnO 2 @AuPt modified electrode, which indicated the potential utilizations of the hybrid based on CNT@SnO 2 for electrochemical sensing.