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Updated: May 28, 2026
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A Method to Fabricate Disconnected Silver Nanostructures in 3D
Published on: November 27, 2012
Scalable Synthesis of High-Density Ultrafine Spherical Silver Powders
Xi He1, Jiangyong Pei2, Xiaocai He3
1State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China.
Materials (Basel, Switzerland)
|May 27, 2026
Summary
This study developed a scalable process for producing ultrafine silver powders for photovoltaic pastes. The integrated method overcomes limitations in liquid-phase reduction, yielding high-quality powders with controlled properties.
Area of Science:
- Materials Science
- Chemical Engineering
- Nanotechnology
Background:
- Ultrafine spherical silver (Ag) powders are crucial conductive fillers for advanced photovoltaic paste formulations.
- Current liquid-phase reduction methods face challenges in scale-up, including uncontrolled nucleation, secondary agglomeration, and precursor passivation.
Purpose of the Study:
- To investigate and establish a process-integrated synthesis chain for kilogram-scale production of ultrafine spherical Ag powders.
- To overcome limitations in current Ag powder production for photovoltaic applications.
Main Methods:
- A flow-field-enhanced dissolution process for silver ingot passivation and a multi-stage NaOH spray system for NOx emission control.
- Utilized ascorbic acid for controlled nucleation and growth, guided by LaMer model principles.
- Employed molecular dynamics simulations and RDF analysis to understand synergistic dispersion mechanisms involving PVP and gum arabic.
- Developed a 20 L pilot reactor with optimized fluid dynamics and high-pressure cleaning for uniform supersaturation.
- Applied ethanol displacement and supersonic jet milling for final powder processing.
Main Results:
- Achieved kilogram-scale production of Ag powder with D50 = 1.90 µm, tap density = 6.0 g/mL, specific surface area = 0.6 m²/g, and LOI (538 °C) = 0.98%.
- Successfully reduced NOx emissions to 186 mg/m³, meeting GB31573-2015 standards.
- Demonstrated powder-level characteristics suitable for photovoltaic paste formulation.
Conclusions:
- The developed process-integrated synthesis chain enables scalable production of high-quality ultrafine silver powders.
- The optimized method addresses key challenges in precursor preparation and powder production for photovoltaic applications.
- The resulting silver powders exhibit properties relevant for advanced photovoltaic paste formulation.
