Atomic plane-selective deposition of gold nanoparticles on metal oxide crystals exploiting preferential adsorption of additives

A strategy of using preferential adsorption of additives for selectively depositing gold metal particles on specific crystallographic planes of Cu(2)O and ZnO crystals was demonstrated. Cu(2)O crystals and ZnO crystals were first electrochemically deposited on a conducting substrate, and gold particles were electrochemically or photochemically deposited on these crystals with the presence of appropriate additives. Preferential adsorption of sodium dodecyl sulfate on {111} planes of Cu(2)O crystals, which was previously used to form octahedral shapes of Cu(2)O crystals, effectively inhibited gold deposition on {111} planes of Cu(2)O, resulting in selective gold deposition on {100} planes. In a similar manner, the use of Cl(-) ions that adsorb selectively on polar {0001} planes of ZnO resulted in selective deposition of gold particles on the {01-10} planes of ZnO rods. The simple chemical method for selective metal deposition described in this study is based on utilizing preferential adsorption of additives as an in situ generated mask to protect certain atomic planes from metal deposition, which significantly simplifies the procedure to assemble precisely controlled composite structures.