Promotion of efficient chlorine evolution reaction by d-p hybrid orbitals in hollow porous CoNiSe2/NiSe2 nanosheet arrays

The demand for Cl 2 is increasing globally, and the chlorine evolution from seawater is a promising technique in the chlor-alkali field to generate chlorine gas. Here, we constructed a novel hollow porous CoNiSe 2 /NiSe 2 nanosheet array for the electrosynthesis of chlorine in seawater-like solution. The CoNiSe 2 /NiSe 2 heterostructures were generated by ion exchange and calcination, which can improve their stability. Moreover, the formed porous hollow nanostructures show an ultra-high specific surface area due to the unique morphology and crystal structure, which can provide channels for mass transfer between the electrolyte and the surface of catalysts and expose more catalytically active sites for accelerating the reaction process. What is impressive is that the hybrid coupling of the Se 4p orbital and the Co/Ni 3d orbital in the heterointerface further reduces the reaction energy barrier of the chlorine evolution reaction (CER). The hollow porous CoNiSe 2 /NiSe 2 nanosheet arrays only exhibit an overpotential of 108 mV to reach the current density of 100 mA cm −2 in an acidic medium containing 4.0 M NaCl. Furthermore, the hollow porous CoNiSe 2 /NiSe 2 nanosheet arrays showed excellent stability and Cl 2 selectivity. The designed transition metal selenides provide a choice for the further development of non-noble metal-based catalysts in the chlor-alkali industry.