本篇論文利用兩步驟植晶法合成約200至300 nm長的鈀奈米棒和具分支的鈀奈米粒子，並將其應用在鈴木偶合的催化反應。我們發現合成鈀材料的過程中，在第二步植晶裡添加不同量的醋酸銅溶液可以達到延長奈米棒長度的效果或生成分支狀的奈米粒子。當添加50至100 μL的醋酸銅溶液可得到200至300 nm長的鈀奈米棒，而這些長奈米棒在反應瓶中會形成沉澱，故可直接將奈米棒和奈米粒子做簡單地分離，進而達到純化的效果；若添加醋酸銅溶液的量增加至250 μL時，發現產物生成分支的奈米粒子。我們認為因銅的電位低於鈀，所以銅離子可不斷地在鈀晶種上進行還原沈積與再氧化，以輔助鈀沉積於短奈米棒或奈米粒子上，達到延長奈米棒或形成分支粒子的效果。在銅離子濃度較低時，因奈米棒的側邊受界面活性劑保護故選擇性地沉積在奈米棒的兩端，進而增加奈米棒的長度；反之當銅離子濃度較高時則隨機沉積在鈀晶種上，造成分支奈米粒子的產生。紫外光可見光吸收光譜顯示當奈米棒長度增長，吸收光譜會有紅位移的現象。
將合成的鈀奈米棒和分支鈀奈米粒子作為鈴木偶合反應的催化劑，實驗發現不論是鈀奈米棒還是具分支的鈀奈米粒子在催化上都具有很高的效率且產率都在90%以上，還能重複地進行反應並可維持很高的催化活性，而晶體本身也具有對環境的熱穩定性以及易與產物分離的好處。

In this study, we have used a simple seed-mediated synthesis process to prepare uniform Pd nanorods with average lengths of ~ 200 and 300 nm and display a penta-twinned structure through the addition of 50–100 □L of 0.004 M Cu(OAc)2 solution into the growth solution for the first time. These long nanorods settle nicely to the bottom of the growth vial to form a precipitate, and can easily be separated from the faceted particles. The nanorods have an average diameter of ~ 20 nm, so they have high aspect ratios of 10–15 or more. By increasing the volume of Cu(OAc)2 solution added to 250 □L, extensively branched Pd nanocrystals were synthesized. The growth mechanism was studied and showed that a mixture of short Pd rods and faceted particles were formed first, and elongated into long rods or branched nanocrystals with the assistance of copper atom deposition. A lower reduction potential of copper than that of palladium leads to reduction and reoxitation of copper ions on the growing rods and faceted particles. UV–vis spectra of the Pd nanorods showed that the longitudinal band of the Pd nanorods
with high aspect ratios red-shifts to longer wavelengths in the near-infrared region.
Both the nanorods and branched nanocrystals were tested for the application as catalysts for Suzuki coupling reactions. They were found to be highly efficient and recyclable catalysts. These crystals are also thermally stable under the reflux condition and can be easily removed from the product solution.

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