Magnetron Sputtering Converts Natural Olivine Rock into CO2-Active Nanoparticles at Room Temperature

The method uses argon-hydrogen plasma in a nanoparticle generator to sputter a polished olivine target, with yield tuned by hydrogen fraction and aggregation length. Resulting particles, 5-20 nm, were collected on substrates and exposed to ambient air. XPS, TEM, and FTIR confirmed both retention of forsterite stoichiometry and formation of carbonate species within hours. Hysteresis in plasma power response suggests a route to pulsed, low-energy operation. This bypasses mechanical milling energy costs that have limited prior nanoscale olivine work.

Prior olivine mineralization studies relied on crushed or synthesized powders under 100-200 °C and elevated pCO2. The sputtering route operates at ambient conditions and directly converts abundant rock feedstock, addressing both cost and scalability barriers highlighted in 2023-2025 DAC roadmaps. Integration with existing thin-film deposition infrastructure could allow distributed, modular capture units rather than centralized plants.

Key limitation remains mass throughput; current lab-scale rates are milligrams per hour. Reaching kilogram-scale will require larger targets and continuous-feed geometries. If successful, the approach links precision vacuum processing to gigaton-scale carbon removal by turning a common mafic mineral into a high-surface-area reagent.

Next steps include in-situ mass spectrometry during exposure and life-cycle assessment against aqueous mineral carbonation baselines. Pilot tests on roof-top air flows are planned within two years if yield improves by two orders of magnitude.