Chen Mengtian, Ye Zhongju, Wei Lin, Yuan Jie, Xiao Lehui
State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, College of Chemistry, Nankai University, Tianjin 300071, China.
College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China.
J Am Chem Soc. 2022 Jul 20;144(28):12842-12849. doi: 10.1021/jacs.2c04202. Epub 2022 Jul 8.
Bimetallic nanostructures are a promising candidate for plasmon-driven photocatalysis. However, knowledge on the generation and utilization of hot carriers in bimetallic nanostructures is still limited. In this work, we explored Pt position-dependent photocatalytic properties of bimetallic Au nanobipyramids (Au NBPs) with single-molecule fluorescence imaging. Compared with all-deposited core-shell nanostructures (aPt-Au NBPs), single-molecule imaging and simulation results show that the end-deposited bimetallic nanostructures (ePt-Au NBPs) can maintain a strong electromagnetic (EM) field and further promote the generation and transfer of energetic hot electrons for photocatalysis. Even though the Pt lattice is more stable than Au, the strong EM field at the sharp tips can boost lattice vibration, where enhanced spontaneous surface restructuring for active reaction site generation takes place. Significantly enhanced catalytic efficiency from ePt-Au NBPs is observed in contrast to that of Au NBPs and aPt-Au NBPs. These microscopic evidences offer valuable guidelines to design plasmon-based photocatalysts, particularly for bimetallic nanostructures.
双金属纳米结构是等离子体驱动光催化的一个有前途的候选材料。然而，关于双金属纳米结构中热载流子的产生和利用的知识仍然有限。在这项工作中，我们通过单分子荧光成像探索了双金属金纳米双锥（Au NBPs）的铂位置依赖性光催化性能。与全沉积核壳纳米结构（aPt-Au NBPs）相比，单分子成像和模拟结果表明，端部沉积的双金属纳米结构（ePt-Au NBPs）可以保持强电磁场（EM），并进一步促进用于光催化的高能热电子的产生和转移。尽管铂晶格比金更稳定，但尖锐尖端处的强电磁场可以促进晶格振动，在此发生增强的自发表面重构以产生活性反应位点。与Au NBPs和aPt-Au NBPs相比，观察到ePt-Au NBPs的催化效率显著提高。这些微观证据为设计基于等离子体的光催化剂，特别是双金属纳米结构，提供了有价值的指导。
