A Biotemplating Route for the Synthesis of Hierarchical Fe₂O₃ with Highly Dispersed Carbon as Electron-Transfer Channel

Although the preparation of carbon composites has made great progress, the construction of systems comprising uniformly dispersed carbon as a framework to link active constituents still remains a challenge. Herein, a hierarchical Fe₂O₃/C composite was synthesized in a one-step biotemplating route, where agarose was firstly reacted with Fe³⁺ and Ca²⁺ ions, which resulted in a competitive interaction between these ions and the hydroxy groups, then partly calcined to achieve the final product that consisted of α-Fe₂O₃ nanoparticles embedded in highly dispersed carbon. The carbon within the composite acts as an efficient photoelectron transfer channel to improve conductivity during photocatalysis. The hierarchical Fe₂O₃/C composite exhibited a photodegradation rate constant (k) of 0.091 min⁻¹, more than four times that of α-Fe₂O₃ (0.020 min⁻¹).