标题： 金-钯天线-反应器纳米颗粒中的倒置温度梯度 显示英文标题

标题： Inverted Temperature Gradients in Gold-Palladium Antenna-Reactor Nanoparticles

摘要： 除了增强的场和可能的电荷转移，纳米尺度光热能的集中是等离子体驱动光化学的基础。 我们展示了一种在金纳米颗粒上附有钯卫星的双金属天线-反应器系统中能量耗散过程中热量定位的进一步增强。 在脉冲激发金核后，卫星收集几乎所有的光热能并升温180 K，而吸光金核保持较冷。 通过比较一系列双金属纳米颗粒与三温模型的瞬态吸收动力学，我们可以精确评估电子和振动子系统的温度。 我们发现了一个强烈的反向温度梯度，其方向与能量输入相反，并将光能集中在活性催化纳米位点。 显示英文摘要

摘要： In addition to enhanced fields and possible charge transfer, the concentration of photothermal energy at the nanoscale is a foundation of plasmon-driven photochemistry. We demonstrate a further enhancement of heat localization during the dissipation of energy in a bimetallic antenna--reactor system with palladium satellites attached to a gold nanoparticle. After pulsed excitation of the gold core, the satellites collect nearly all photothermal energy and heat up by 180\,K while the light-absorbing gold core remains much colder. By comparing transient absorption dynamics of a series of bimetallic nanoparticles with a three-temperature model, we can precisely assess the temperatures of the electronic and vibrational subsystems. We find a strong inverted temperature gradient that opposes the direction of energy input and concentrates the light energy at the active catalytic nanosite.