Nonthermal Plasma Synthesis of Nanocrystals: Fundamental Principles, Materials, and Applications

Abstract

Nonthermal plasmas have emerged as a viable synthesis technique for nanocrystal materials. Inherently solvent and ligand-free, nonthermal plasmas offer the ability to synthesize high purity nanocrystals of materials that require high synthesis temperatures. The nonequilibrium environment in nonthermal plasmas has a number of attractive attributes: energetic surface reactions selectively heat the nanoparticles to temperatures that can strongly exceed the gas temperature; charging of nanoparticles through plasma electrons reduces or eliminates nanoparticle agglomeration; and the large difference between the chemical potentials of the gaseous growth species and the species bound to the nanoparticle surfaces facilitates nanocrystal doping. This paper reviews the state of the art in nonthermal plasma synthesis of nanocrystals. It discusses the fundamentals of nanocrystal formation in plasmas, reviews practical implementations of plasma reactors, surveys the materials that have been produced with nonthermal plasmas and surface chemistries that have been developed, and provides an overview of applications of plasma-synthesized nanocrystals.

The 2017 Plasma Roadmap: Low temperature plasma science and technology

“…In general, inorganic nanomaterials can be classified into zero, one and two-dimensional (2D) materials. The plasma synthesis of zero-dimensional (0D) nanomaterials, quant um dots or nanocrystals has found significant adoption, due to the ability of plasma to synthesize materials that are difficult to synthesize with other approaches [66]. Efforts initially focused on strongly covalently bond mat erials, such as the group IV materials silicon, germanium and carbon, but have more recently also included group IV alloys.…”

“…Efforts initially focused on strongly covalently bond mat erials, such as the group IV materials silicon, germanium and carbon, but have more recently also included group IV alloys. More contemporary efforts have expanded the mat erials studied with plasma synthesis to doped nanocrystals, as well as metal oxides, nitrides and sulphides [66]. Among one-dimensional (1D) nanomaterials, the main emphasis of plasma research has been on carbon nanostructures, including single-and multiwall carbon nanotubes and carbon nanofibers.…”

In-situ analysis of optically thick nanoparticle clouds

“…Focusing on plasmas, nanoparticles are an unwanted byproduct of fusion devices [1,2] and in plasma reactors used in the semiconductor industry [3]. Plasma aided processes are used to create nanoparticles with unique features [4], like amorphous silicon particles [5], or to embed particles in surfaces [6]. Simulations of growth processes in reactive plasmas are on an elaborated state and give detailed insight into the growth dynamics and the spatial size distribution of the nanoparticles [7].…”

Plasma‐Made (Ni0.5Cu0.5)Fe2O4 Nanoparticles for Alcohol Amination under Microwave Heating

“…To obtain crystalline and well‐defined NPs, high temperatures are required to decompose NP precursor and allow ordered growth. In liquid phase though, ligand‐free NP agglomeration is difficult to avoid, driving the search for solid‐state or gas phase processes . Taking these considerations into account, we turned to induction plasma as a technique for the synthesis of Ni/Cu‐containing NPs.…”