No abstract

The simple irradiation of 355 nm nanosecond laser pulses to SiO2@Pt core–shell nanospheres at fluence of 2.7 mJ cm–2 during the preparation process of hollow platinum nanospheres has been found to enhance the catalytic performances of platinum nanocatalysts on a large scale. Laser irradiation has transformed platinum nanoclusters topped on silica nanospheres into well-defined platinum nanoshells having uniform and smooth surfaces; the thickness of platinum nanoshells has been tuned easily by adjusting the irradiation time only. Laser irradiation increases the catalytic performances of hollow platinum nanospheres in the degradation of rhodamine B in the presence of KBH4 by five times via lowering the energy barrier. The energetically more favorable formation of the activated complexes in the nanocavity surfaces is suggested to reduce the activation energy substantially. The restructuring of surface atoms induced by photothermal annealing during laser irradiation has rendered the metallic surfaces much easier to chemisorb reactants and to facilitate electron relays, enhancing the catalytic performances of platinum nanocatalysts extensively.

The controlled fabrication, characterization, and application of nanometer-sized materials with functional properties have been studied widely.1-3 Metal nanostructures attract considerable attention scientifically as well as industrially owing to their intriguing chemico-physical properties that can be tailored as functions of nanoparticle sizes, shapes, and mutual interactions.4,5 In particular, noble-metal nanostructures have attracted enormous attention in various fields of study because of their novel properties, including large optical-field enhancements resulting in the strong scattering and absorption of light. They have possible uses in diverse applications such as devices, transistors, optoelectronics, information storages, and energy converters.1,6 Among various noble-metal nanostructures, platinum-based nanostructures especially have attracted widespread interest as platinum plays an outstanding role in multifunctional catalysts for many industrial reactions. However, because there are some crucial obstacles such as low platinum-utilization efficiency and high cost, some ways must be found to reduce the amount of platinum used in a specific application by increasing its catalytic activity in order to lower the overall cost.