Palladium nanoparticles deposit on multi-walled carbon nanotubes and their catalytic applications for electrooxidation of ethanol and glucose

A facile spontaneous redox method is developed to obtain uniform palladium nanoparticles (PdNPs) distributed on surfactant-functionalized multi-walled carbon nanotubes (MWCNTs) at room temperature. In this synthesis, hexadecyltrimethylammonium bromide (CTAB) was self-assembled onto MWCNTs to provide adsorption sites for PdCl42− ions. Interestingly, PdCl42− was spontaneously reduced though a galvanic cell effect between PdCl42− and MWCNTs. The as-prepared Pd catalyst showed excellent catalytic activity toward oxidation of ethanol and glucose in an alkaline medium. Inspired by this, a glucose enzyme-free biosensor was developed with a wide linear range covering from 1 mM to 20 mM and a high sensitivity of 11 μA mM−1 cm−2 (to 1-10 mM) and 6.3 μA mM−1 cm−2 (to 11-20 mM). These results indicate that the as-synthesized Pd catalyst could be a great potential material for improving performance of direct ethanol fuel cells and glucose sensors.