Carrageenan Asissted Synthesis of Palladium Nanoflowers and Their Electrocatalytic Activity toward Ethanol

Palladium (Pd) nanoflowers with tunable thorns were prepared by a facile and rapid route with the assistance of carrageenan. The superior nature of well-dispersed Pd nanoflowers has been disclosed by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy measurements. The growth of thorns of Pd nanostructures was first stimulated with the continuous introduction of l-ascorbic acid in the synthesis system and then reached a maximum length of about 132 nm, followed by a slight decrease in concentration. Electrochemical data showed that Pd nanoflowers with the longest thorns exhibited the highest catalytic current density of 1160 mA/mg, optimized tolerance to the poisoning, and the lowest onset potential while others showed a better cycle stability with a catalytic activity maintenance of above 96% after 300 cycles. It is suggested that the structure of thin thorns of Pd nanoflowers should be easier to damage than thick thorns during the electrocatalysis of ethanol. The relatio...