Microgalvanic cell-mediated green synthesis of Cu2O nanocubes with (100) facets for boosting dopamine hydrochloride sensing performance.

Despite numerous efforts have been made on exploring the preparation, properties and application of Cu₂O nanocrystal, there is still a lack of a facile and green synthesis strategy to obtain well-defined Cu₂O nanocubes (NCs). And exploration of the superior low-index lattice plane of Cu₂O in electrochemical sensing is also inadequate. Herein, we proposed a Ni(OH)₂-mediated in-situ synthetic strategy for the preparation of Cu₂O NCs enclosed by low-index facets with simple procedure, mild temperature and low energy-consumption. The Ni(OH)₂ sites not only facilitated the contact between Cu²⁺ and the substrate Ni foam (NF), but also can combine with the NF to act as a primary battery to regulate the nucleation and growth rate of Cu₂O (100) facets. Benefiting from the high ratio of exposed electroneutral (100) lattice planes of nanocubes, the Cu₂O NCs formed on Ni(OH)₂-abundant Ni Foam (Cu₂O NCs/NF_EO) exhibited a wide linear range (3.25-1178.8 μM), a low detection limit (1.86 μM) and a high sensitivity (900 μA mM^-1 cm^-2) in dopamine hydrochloride (DAH) electrochemical sensing. This work expects to provide more clues about the relationship between different dominant low-index facets of Cu₂O NCs and electrochemical sensing performance towards DAH, and thereby contributes to the development of functional materials based on Cu₂O nanocrystals with desirable facets.