Fabrication of a composite based on aluminum oxide nanofibers and nanodiamonds to construct phenol detection systems

A composite based on aluminum oxide nanofibers (AONF) and modified nanodiamonds (MND) synthesized by explosion technique was made by mixing aqueous suspensions of components at a 5:1 weight ratio and incubating the mixture for 15 minutes at 32 C. It is assumed that the formation of a composite is provided by the difference in the zeta-potentials of the components - negative for MND and positive for AONF. Vacuum filtration of the mixture through a fluoroplastic filter (pore diameter of 0.6 m) formed discs with a diameter of 40 mm with subsequent heat treatment at 300 C to impart structural stability to the composite. Using scanning electron microscopy (SEM), it was revealed that the resulting composite has a network structure in which the MND particles are distributed over the AONF surface. It was established that MND incorporated into the composite catalyze the azo coupling reaction (phenol - 4-aminoantipyrine - H2O2) with the formation of a colored product (quinoneimine). The applicability of the composite for the multiple detection of phenol in aqueous samples is demonstrated.