Synthesis of sub-1 nm 2D transitional metal oxides via anion exchange-bonds cleavage cascade reactions

Two-dimensional (2D) transition metal oxides (TMOs) are widely applied in various research fields. A reliable, general, and facile synthetic protocol applicable for a large variety of 2D TMOs is in emergent demand. S-S/Se-Se bonds widely exist in various metal sulfide/selenide layered crystals. We demonstrated that 2D TMOs could be fabricated from metal sulfide/selenide with S-S bonds or Se-Se bonds by a novel H2O2-mediated anion exchange bonds cleavage cascade reactions strategy. Specifically, the addition of H2O2 induced the anion exchange in these crystals from S-S/Se-Se to O-O. The O-O bond is fragile than S-S or Se-Se bond, proving by the density functional theory (DFT) calculations. Then, the O-O bonds in the layered crystals were cleavaged to form the sub-1 nm 2D TMOs. 2D CuO2, CuO, and Mn3O4 were fabricated by this method successfully. As an exaple of appilication, we used the ultrathin 2D CuO2 as a biomaterial for cancer treatment. 2D CuO2 have easier biodegradability, more robust reactivity, and higher drug loading efficiency than CuO2 nanoparticles.

Automated summary

This study presents a reliable, general, and facile method for the synthesis of various 2D TMOs through a cascade reaction strategy involving the cleavage of oxide bonds in the presence of H2O2. The fabricated 2D CuO2, CuO, and Mn3O4 show potential applications in cancer treatment, with enhanced biodegradability, reactivity, and drug loading efficiency compared to CuO2 nanoparticles.