Fabrication of bimetallic Pd/Pt nanostructure deposited on copper nanofoam substrate as a novel sorbent for solid phase microextraction method

Nano materials and structures play an important role in technologies such as energy applications, catalytic properties, separation science, fuel cells and water splitting. The structure of supporting materials is very important. The producing 3-D nanofoam structure of metals with highly porous dendritic is a simple and very effective method. This process is done by the electrochemical deposition accompanying hydrogen evolution. In this technique, produced hydrogen bubbles are as a dynamic template for metal deposition with dense metallic components and unique pore size distribution. Solid phase microextraction (SPME) is a simple, sensitive, solvent free, portable, easy to automate and environmentally friendly microextraction technique applicable for the extraction of analytes from various matrices. The main disadvantages of SPME are the limited selection of commercially available fibers, fragility and limited lifetime of the fiber, and easy swelling in organic solvents. Therefore, most attempts have been focused on obviating the disadvantages of SPME. In this work, the Pd/Pt bimetallic nanofoam was fabricated on Cu nanofoam substrate. The substrate was electrochemically prepared by copper reduction during 3 seconds and covered with Pd/Pt by galvanic replacement reaction in aqueous solutions of Pd (II) and Pt (IV). Then the prepared fiber was used as the sorbent for solid phase microextraction (SPME) method for the extraction and analysis of BTEX from the environmental samples as the HS-SPME method. The experimental parameters such as desorption temperature, desorption time, salt concentration, sample temperature, equilibrium time and extraction time, were optimized by experimental design method. The fiber-to-fiber reproducibility for three fibers prepared under the same condition was 6.4-7.8%.