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

Abstract 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.