大气压低温微等离子体合成法:原理、装置与应用OA

The development of atmospheric-pressure low-temperature microplasma provides a unique and promising route for the synthesis of multifunctional nanomaterials.Depending on the type of discharge and the distribution of the electric field,the atmospheric-pressure low-temperature microplasma could generate stable discharges in the gas phase,liquid phase,and at the gas-liquid interfaces,forming various low-temperature microplasma states such as glow discharge,dielectric barrier discharge,and corona discharge.The synthesis mechanism relied on the abundant reactive species-such as photons,electrons,ions,free radicals,and excited molecules and atoms-present within the interior and boundary layer of the microplasma.High-energy electrons excited or dissociated the background gas and precursor molecules through inelastic collisions,generating reactive species.These reactive species acted as initiators or reducing agents,inducing cleavage,reduction,or polymerization of precursors,thereby promoting nucleation and growth of the target materials.Since the microplasma was in a non-thermodynamic equilibrium state,where the electron temperature was much higher than the macroscopic gas temperature,while the gas temperature could remain near room temperature,the combination of high-energy activation and a mild thermal environment provided unique reaction conditions for material synthesis.At the same time,the confinement effected within the microscale discharge space significantly shortens the diffusion paths of reactants and active species,markedly reduced mass transfer resistance,and thus facilitates highly efficient reactions.Compared with traditional wet-chemical synthesis or conventional electrochemical deposition,this method offered several distinct advantages:the synthesis typically took only tens of minutes,considerably shorter than the several hours or even days required by traditional methods;no surfactants or strong reducing agents were needed,as the reaction was driven solely by the reactive components inherent to the plasma,thereby avoiding byproduct impurity;and the apparatus was compact,energy-efficient,and operable under mild conditions at ambient temperature and pressure.Furthermore,by adjusting the discharge parameters,the types and concentrations of reactive species could be effectively controlled,thereby enabling regulation of the synthesis process.This article reviewed the fundamental principles of this synthesis method,the various reactor configurations(such as discharge mode into hollow-electrode reactors,microplasma jet reactors,dielectric barrier discharge reactors,and array reactors),as well as the synthesis of diverse nanomaterials-including metal oxides and composites,organic framework compounds,noble metal nanoparticles,and carbon-based nanomaterials.Recent applications in analytical testing were also summarized,demonstrating the promising application of this technique in fields such as precision nanomaterial synthesis,green chemistry,and analytical sensing.