Straightforward synthesis of magnetized activated carbon particles

Abstract

To develop new sustainable processes, the production of materials with specific physico-chemical properties is highly desirable. Creating hybrid multi-functional materials by combining​ complementary components represents a suitable approach to meet the requirements of various industrial processes. In this work, a straightforward production route to synthesize magnetic (electrode) particles from low cost starting materials is presented. The particles were produced from iron(II) hydroxide and activated carbon (AC) via a microwave-assisted synthesis, creating a magnetite and AC hybrid material (PMAG/AC). SEM imaging shows that the particles are characterized by an amorphous surface structure, typical for AC. Visible cavities are covered by magnetite nanoparticles, confirming the specific surface area measurements, which show a reduction of the surface area when magnetite is added. Cyclic voltammetry shows increasing current densities, ranging from ＋0.49 to ＋1.31 mA cm−2 and from −0.58 to −1.47 mA cm−2 at ＋/−1000 mV vs. Ag/AgCl with increasing immobilized particle mass (25 to 124 mg cm−2). Finally, adsorption experiments were conducted by adding the particles to a culture of electroactive Shewanella oneidensis showing a time-dependent adsorption behavior. These findings represent a promising perspective for future applications of magnetic, conductive and biocompatible particles across a broad range of biotechnological and (bio-)electrochemical processes.