Hierarchical Cu₂Se nanostructures film for peroxymonosulfate activation and electrocatalytic hydrogen evolution

Copper selenide (Cu₂Se) nanostructures film was synthesized on a Cu substrate utilizing the hydrothermal method. The Cu₂Se nanostructures were used to activate the peroxymonosulfate (PMS) and electrocatalytic hydrogen evolution (HER). The Cu₂Se nanostructures film was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), elemental mapping analysis and high-resolution transmission electron microscopy (HR-TEM). A single phase and vertically grown hierarchical Cu₂Se could be identified in the XRD and SEM. EDAX analysis and their mapping show that the elements are homogeneously distributed over the entire matrix. The microstructural formation of Cu₂Se film was characterized by HRTEM. Activation of PMS was performed under various experimental conditions, such as different concentrations of PMS and at different pH levels. The formation of free radicals was further analyzed utilizing scavenger techniques. The degradation pathway was analyzed using the mass spectrometer. The copper selenide film was reused in four continuous cycles without any efficiency loss. XRD analysis on the reused copper selenide film was carried out and there was no displacement of the measurable XRD peaks. The HER activity of Cu₂Se film was higher than the bare Cu Foil. The stability of the Cu₂Se film was unaffected even after its use in 500 cycles in an acidic medium.