Synthesis of Silver Gallium Selenide (AgGaSe2) Nanotubes and Nanowires by Template-Based Electrodeposition.

In this work, a systematic investigation of the different parameters that control the electrodeposition processes was carried out at the aim to synthetizing AgGaSe2 nanostructures. We found that pH is a key parameter to control both the morphology and composition of the nanostructures. Low pH favours mainly the formation of Ag2Se nanotubes with a scarce mechanical stability, while multi-phase nanowires well anchored to the substrate were obtained at higher pH. We also found that it was necessary to increase dramatically the concentration of the gallium precursor into the deposition bath in order to obtain AgGaSe2 owing to lower redox potential of the Ga3+/Ga couple than Ag2+/Ag and Se4+/Se. Besides, the addition of specific complexing agents to deposition bath was necessary to better control the composition of the nanostructures. By increasing gallium precursor concentration and adding complexing agents, it was possible to obtain for the first time nanostructures of amorphous AgGaSe2 with different amount of Ga via one-step electrodeposition.

Pb-PbOHCl Composite Nanowires Synthesized by Galvanic Deposition in Template.

In this paper, we report a detailed study on the synthesis of composite nanowires of Pb-PbOHCl via galvanic deposition into the pores of a membrane acting as a template. PbOHCl deposition quantitatively occurs as the solution pH exceeds the value of about 4.12. Simultaneously, owing to the galvanic coupling, electro-deposition of lead occurs, so composite nanowires were formed. The role of different parameters controlling the kinetic evolution of the process, such as oxygen bubbling, solution pH, surface area and type of sacrificial anode were investigated one at a time. The results suggest that every modification accelerating the alkalization of the solution inside the template pores favors growth of composite nanowires richer in PbOHCl. Alumina and polycarbonate membranes were investigated as template, and the best results were obtained for polycarbonate membrane, which can be easily removed by dissolution in CHCl3 avoiding the collapse and successive loss of the nanowires.