Metal Clusters, Metal Nanostructures, Semiconductor Nanocrystals, Single-Ion Magnets

金属簇、金属纳米结构、半导体纳米晶体、单离子磁体

• 批准号: RGPIN-2021-03176
• 负责人: Hamilton, Ian
• 金额: $ 1.75万
• 依托单位: Wilfrid Laurier University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=747888
• 关键词: Metal; Clusters; Nanostructures; Semiconductor; Nanocrystals

My research program seeks to understand and optimize the catalytic properties of metal clusters, the optoelectronic properties of the metal nanostructures and semiconductor nanocrystals, and the operational properties of doped gold cluster single-ion magnets. i) How can we optimize the catalytic properties of metal clusters for ethanol oxidation? Ethanol is renewable, biodegradable, hydrogen rich and can be oxidized to synthesize a wide range of valuable chemicals. We examined the ability of unsupported coinage metal clusters to catalyze the first step of ethanol oxidation at zero Kelvin. We found that copper clusters were better catalysts than silver or gold catalysts and that anionic clusters are better than neutral clusters, and that single M atoms are better catalysts than M2, M3, and M4. These results will guide our future studies of supported metal clusters at finite temperature. ii) How can we optimize the optoelectronic properties of metal nanostructures and semiconductor nanocrystals? For metal nanostructures we will focus on gold since it is relatively unreactive and can adopt many (locally) stable geometries. Our focus is on gold rod structures because they could be used as electrical connectors in nanostructured devices. Semiconductor nanocrystals are used in photovoltaic devices. Upon absorption of a photon, an electron-hole pair is formed and an electrical current can be generated. They are also used in display devices in which the reverse process takes place. Due to quantum confinement, a smaller nanocrystal has a larger band gap, which makes better use of higher energy photons. Under experimental conditions these species are typically cadmium rich (and positively charged) and must be passivated using negatively charged X-type ligands e.g. Cd16Se10Cl12 and Cd59Se50(CH3COO)18. Motivated by experimental studies, we will examine the effect on charge mobility of doping small CdSe nanocrystals with silver atoms. Also, we will examine the magnetic properties of CdSe nanocrystals doped with a high-spin atom such as Mn, Fe, or Co. iii) How can we optimize the magnetic properties of novel single-ion magnets? Single molecule magnets (SMMs) have potential for use as quantum bits (qubits) in quantum information processing devices. SMMs typically have six to twelve high-spin atoms connected to one another via oxygen or nitrogen bridging atoms. Our primary objective is to gain insight into a subset of SMMs called single ion magnets (SIMs) which are usually comprised of a ligand-protected high-spin atom that is trapped in a crystal lattice with fixed SIM-SIM distances. If a gold cluster is doped with a high-spin atom such as Mn, Fe, Co then, due to the greater electronegativity of Au, the high-spin atom will have a positive charge. These species are therefore a novel type of "free standing" SIM that could be arrayed on a surface with optimum SIM-SIM distances. This could result in a qubit with unique functionality.

我的研究计划旨在理解和优化金属簇的催化特性，金属纳米结构和半导体纳米晶体的光电特性以及掺杂的金簇单离子磁体的操作特性。 i）如何优化金属簇的催化特性用于乙醇氧化？乙醇可再生，可生物降解，富含氢，可以氧化以合成各种有价值的化学物质。我们检查了无支撑的造币金属簇催化零开尔文处乙醇氧化的第一步的能力。我们发现，铜簇比银或金催化剂更好，并且阴离子簇比中性簇更好，并且单个M原子比M2，M3和M4更好。这些结果将指导我们未来对有限温度下支持金属簇的研究。 ii）如何优化金属纳米结构和半导体纳米晶体的光电特性？对于金属纳米结构，我们将专注于黄金，因为它相对不反应，并且可以采用许多（本地）稳定的几何形状。我们的重点是黄金结构，因为它们可以用作纳米结构设备中的电连接器。半导体纳米晶体用于光伏设备。吸收光子后，会形成电子孔对，并可以产生电流。它们还用于进行反向过程的显示设备。由于量子限制，较小的纳米晶体具有较大的带隙，可以更好地利用较高的能量光子。在实验条件下，这些物种通常具有富含镉的富含镉（并带正电荷），并且必须使用带负电荷的X型配体进行钝化，例如CD16SE10CL12和CD59SE50（CH3COO）18。通过实验研究的促进，我们将研究用银原子掺杂小CDSE纳米晶体的电荷迁移率的影响。另外，我们将检查用高旋转原子（例如Mn，Fe或Co.III）掺杂的CDSE纳米晶体的磁性特性。III）如何优化新型单离子磁体的磁性？单分子磁铁（SMM）在量子信息处理设备中有可能用作量子位（Qubits）。 SMM通常通过氧或氮桥接原子相互连接的六到十二个高旋转原子。我们的主要目的是洞悉称为单个离子磁铁（SIMS）的SMMS集，该子集通常由由配体保护的高旋转原子组成，该高旋转原子被困在具有固定的SIM-SIM距离的晶格中。如果金簇用高旋转原子（例如Mn，Fe，co）掺杂，则由于AU的电负性较高，高旋转原子将具有正电荷。因此，这些物种是一种新型的“自由式” SIM的类型，可以在最佳的SIM-SIM距离的表面上排列。这可能会导致具有独特功能的量子。