Frugal nanomanufacturing for sustainable research infrastructure: a reuse-oriented framework for carbon nanotube synthesis

Limited access to nanomaterials synthesis infrastructure constrains resource-limited institutions, where commercial chemical vapor deposition (CVD) systems are often unaffordable. This study reports a reuse-oriented tubular CVD setup and a screening-level techno-economic analysis (TEA) framework for frugal carbon nanotubes (CNTs) production. Hardware capital expenditure (CAPEX) amounted to CAPEXP=4,310.00 USD (prototype) and CAPEXR=7,046.17 USD (replication). As a case study, acetylene decomposition over Fe-Co/CaCO3 at atmospheric pressure produced raw CNTs (RCNTs); subsequent acid leaching yielded purified CNTs (PCNTs). Characterization via scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and X-ray diffraction (XRD) confirmed a filamentous/tubular carbon morphology and the strong attenuation of CaCO3 reflections after purification, consistent with effective removal of the bulk catalyst support. Using the dry PCNTs mass as the functional unit and local 2025 prices, the TEA estimated a unit production cost of Cp,OPEX=517.87 USD/g and a levelized cost of Cp,LC=606.59 USD/g, with operating expenditures (OPEX) dominating under baseline utilization. This approach provides a practical template to quantify cost drivers for in-house CNTs production in resource-constrained academic settings.