A facile solution-phase deposition approach to porous selenium materials

A facile solution-phase deposition method has been developed to synthesize t-Se porous microstructures. Porous flower-like Se patterns and porous apple-like Se microstructures have been successfully fabricated on a large scale by choosing Zn foil as the deposition substrate, and N₂H₄·H₂O or EDTA as both the reducer and the coordinating agent. By varying the experimental parameters, other Se microstructures, such as lotus-root-like porous microspheres, walnut-like porous spheres and ear-like materials, have been prepared. We have demonstrated that the zinc ions released from the surface of the Zn substrate and the soft template formed through the coordination between Zn²⁺ and organic molecules are significant in controlling the porous structure and morphology of the final products in this solution-phase deposition method. It was deemed that the decomposition of N-containing molecules coordinated with zinc ions on the surface of the Zn foil and the following transformation into solutions, and the N₂ generated in the reduction of Na₂SeO₃ are mainly responsible for the formation of pores in the selenium products. In addition, the porous t-Se materials have been shown to electrochemically store hydrogen with good capacity, which is considered to be associated with the porous structure of the obtained samples. This facile solution-phase deposition method can be potentially extended to prepare Te and other materials with porous or other interesting morphologies. Furthermore, these porous Se materials are expected to find wide applications in the fields of hydrogen storage, high-energy batteries, luminescence, optics, electronics and optoelectronics.