Adsorption of Colloidal Platinum Nanoparticles to Supports: Charge Transfer and Effects of Electrostatic and Steric Interactions
Adsorption of Colloidal Platinum Nanoparticles to Supports: Charge Transfer and Effects of Electrostatic and Steric Interactions
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DOI：
10.1021/la502588g
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发表时间：
2014-10-14
期刊：
影响因子：
3.9
通讯作者：
Wagener, Philipp
中科院分区：
文献类型：
--
作者：
Marzun, Galina;Streich, Carmen;Wagener, Philipp
将胶体纳米颗粒吸附到表面和载体上是非均相催化剂、聚合物添加剂或废水处理的便捷方法。我们研究了激光生成且最初无配体的铂纳米颗粒对 TiO2 载体的吸附效率，作为 pH、离子强度和配体表面覆盖度的函数。纳米粒子的吸附主要由静电相互作用控制：如果悬浮液的pH值在纳米粒子和载体的等电点之间，则纳米粒子被吸附并将净电荷转移到载体。由于纳米粒子表面附着有各种配体，这种电荷驱动的吸附不受空间排斥的影响。除了静电相互作用之外，中等离子强度和高于纳米颗粒等电点的 pH 值所带来的胶体稳定性是胶体沉积的先决条件。
Adsorption of colloidal nanoparticles to surfaces and supports is a convenient approach to heterogeneous catalysts, polymer additives, or wastewater treatment. We investigated the adsorption efficiency of laser-generated and initially ligand-free platinum nanoparticles to TiO2 supports as a function of pH, ionic strength, and ligand surface coverage. The nanoparticle adsorption is dominantly controlled by electrostatic interactions: if the pH of the suspension is between the isoelectric point of the nanoparticles and the support, nanoparticles are adsorbed and transfer a net charge to the support. This charge-driven adsorption is not affected by steric repulsion due to various ligands attached to the nanoparticle surface. In addition to electrostatic interactions, colloidal stability given by moderate ionic strengths and pH values above the isoelectric point of nanoparticles are prerequisites for colloidal deposition.