Size control synthesis of palladium oxide nanoparticles by microwave irradiation

Palladium oxide nanoparticles with small sizes and narrow distributions were synthesized by hydrolysis of palladium chloride in the presence of polyvinylpyrrolidone under microwave irradiation. The as-prepared palladium oxide nanoparticles were characterized by transmission electron microscopy, X-ray powder diffraction and X-ray photoelectron spectroscopy. The factors affecting the sizes of palladium oxide nanoparticles were investigated. Due to the rapid and homogeneous heating with microwave, the mean size of the as-synthesized palladium oxide nanoparticles changed slightly with the increase of the initial pH of the precursor solution. A higher concentration of polyvinylpyrrolidone can only accelerate the hydrolysis rate. It was also found that the species of the acid group anion had little effect on the particle size at an approximately equal pH.