Effects of successive additions of two capping ligands on the structural properties of PbO nanoparticles

A cost-effective approach to the synthesis of lead oxide (PbO) nanoparticles by successive additions of two capping ligands using a simple method of precipitation is reported herein. The successive additions of polyvinyl pyrrolidone (PVP) and cetyltrimethyl ammonium bromide (CTAB) cap the Pb(OH)₂ with a primary layer of PVP and a secondary layer of CTAB, forming a bilayer system around Pb(OH)₂. PVP controls the PbO particle size, while CTAB enhances the particle size of the PVP-treated PbO by seeding growth process. The effects of the successive additions of these two capping ligands were studied by varying the relative percentages of PVP and CTAB from 0 to 100 %. From transmission electron microscopy and X-ray diffraction results, it was confirmed that the size of the PbO nanoparticles decreased with a relative increase in the percentage of PVP (and corresponding decrease in the percentage of CTAB). Furthermore, X-ray diffraction results demonstrated the formation of a pure α-PbO phase. Field emission scanning electron microscopy images showed the increase in grain size with the decrease in the percentage of PVP. Infrared spectroscopy depicted the formation of PbO along with the presence of PVP and CTAB covering the particle surface. Thermogravimetric analysis and differential thermal analysis revealed the decomposition of lead oxalate to α-PbO at around 370 °C.