CO诱导Pd蓝纳米片形成机理的理论研究

Theoretical study on the formation mechanism of palladium nanosheets induced by CO

本研究探究了实验上已经得到稳定的小于10个原子层结构的钯蓝纳米片的生长机理。计算结果表明,在CO覆盖度为75%的条件下,相比于包含6、7、9和10层Pd原子层的纳米片而言,8层Pd纳米结构的Mülliken电荷布居为0.007|e|,表明当Pd原子达到8层时吸附的CO和Pd纳米片之间几乎没有发生电子转移,此时具有8层Pd的纳米片是相同条件下最稳定的纳米片。同时也可以看出,吸附在Pd纳米片表面的CO分子可以诱导稳定的Pd蓝纳米片的形成,与实验研究结果相一致。

The formation mechanism of freestanding palladium nanosheets was investigated by the first-principles calculations.The calculations show that the most stable nanostructure is predicted to be the eight-layer nanosheet at the high CO coverage(75%),where CO molecules are adsorbed on the hollow sites of the nanosheet surface.Moreover,there is almost no electron transfer between CO molecules and Pd nanosheet for the 8⁃layer system due to the Mülliken charge of 0.007|e|,suggesting that the 8-layer Pd nanosheet approaches a relatively stable electronic structure.It can be seen that the formation of the stable Pd nanosheet can be induced by the adsorption CO on the surface of Pd nanosheet,which is consistent with the experimental results.