One-pot synthesis of yolk-shell Cu/Cu₂O nanospheres with tunable morphologies for assisting photocatalytic hydrogen evolution

We report a facile, one-pot synthesis of spherical Cu/Cu₂O yolk-shell nanocrystals (Cu/Cu₂O YSNSs) with tunable morphologies and explored their applications for assisting photocatalytic hydrogen evolution. The success of current synthesis relies on the reduction of Cu(NO₃)₂ by ascorbic acid in the presence of octadecyl trimethylammonium chloride (OTAC) and hexamethylenetetramine (HMTA). It is found that the variation of OTAC concentration would lead to the formation of Cu/Cu₂O YSNSs with tunable morphologies. The as-prepared Cu/Cu₂O YSNSs are further anchored by TiO₂ nanoparticles (Degussa P25) to construct Cu/Cu₂O/TiO₂ nanocomposites for applications in photocatalytic H₂ evolution under simulated sunlight irritation. The resulting metal-semiconductor nanostructures have remarkable photocatalytic activity in H₂ evolution from water-methanol mixtures, with the product rate being almost 97 times greater than that of the pure P25 catalysts. Such improvement should be attributed to the unique hollow structure and the presence of multi-valent copperish species. The current study describes a feasible one-pot strategy to synthesize copperish oxide nanocrystals with tunable yolk-shell morphologies and validates their promising use in as co-catalyst for photocatalytic hydrogen evolution to illustrate the advantage from both the structure and composition.