Buying Graphene: A Procurement Guide for Engineers and Managers

Graphene procurement is uniquely difficult. The material comes in half a dozen distinct forms with properties that vary by orders of magnitude, the supply chain is fragmented across hundreds of companies, and a well-documented mislabeling problem means that what is printed on the label may bear little resemblance to what is inside the container. This guide provides a practical framework for specifying, evaluating, and purchasing graphene materials — whether you are buying CVD films for sensor development or GNP powder for composite reinforcement.

The Mislabeling Problem

This is not a minor issue. A landmark 2018 study in Advanced Materials (Kauling et al.) tested graphene products from 60 commercial suppliers and found that fewer than 10% contained material with more than 10% monolayer content. Most products labeled as “graphene” were in fact graphite nanoplatelets or multilayer graphite with marginal performance improvements over conventional carbon fillers.

The problem has two root causes:

No enforced labeling standard. The ISO/TS 80004-13 standard defines monolayer graphene as a single carbon layer and few-layer graphene as 2–10 layers. Material with more than 10 layers is, by this definition, not graphene at all — it is thin graphite. However, ISO standards are voluntary. No regulatory body prevents a supplier from selling 50-layer graphite powder as “graphene nanoplatelets.”

Misaligned incentives. Graphene carries a premium price and marketing cachet. Suppliers face commercial pressure to label their products as graphene even when an honest characterization would call them graphite. The Graphene Council has introduced a verification program that audits supplier claims against measured data, but adoption remains voluntary and coverage is incomplete.

For buyers, the implication is straightforward: supplier claims cannot be taken at face value. Independent characterization data — specifically Raman spectroscopy and transmission electron microscopy (TEM) — is the minimum requirement before committing to a procurement relationship.

Match the Form to Your Application

The most expensive procurement mistake is buying the wrong type of graphene, not overpaying for the right type. Different applications require fundamentally different material properties:

Percolation-driven applications (composites, conductive coatings, anti-static films) — You need a conductive network to form throughout the matrix. This requires high aspect ratio flakes with sufficient lateral size to create inter-flake contacts. Few-layer graphene or GNP with lateral sizes above 5 μm and thickness below 10 nm works well. Monolayer CVD graphene is unnecessary and wildly uneconomical.

Barrier-driven applications (anticorrosion coatings, gas barrier films, packaging) — You need impermeability, which means large flakes with minimal defects that create a tortuous diffusion path. Larger lateral size and low defect density matter more than layer count. GNP with high aspect ratios (lateral size:thickness >1,000) is ideal.

Device-transport applications (sensors, transistors, transparent conductors, photodetectors) — You need the intrinsic electronic properties of pristine graphene, which means monolayer or bilayer CVD graphene with high carrier mobility and low sheet resistance. This is the only category where monolayer graphene is actually required, and it is the smallest market by volume.

Surface-chemistry applications (drug delivery, membranes, catalysis) — You need accessible functional groups and high surface area, which means graphene oxide or functionalized FLG. Pristine graphene is chemically inert and poorly suited to these applications.

Buying CVD monolayer graphene for a composite application wastes money. Buying GNP powder for a Hall sensor wastes time. The form must match the physics.

Key Specifications to Request

For CVD Films

When procuring CVD graphene on substrates, request:

• Raman mapping statistics — Not a single-point Raman spectrum, but a map (minimum 100 points across the sample). Report the percentage of points showing monolayer 2D/G ratio (≥2.0), the average D/G ratio (<0.1 for high quality), and the spatial uniformity. A single “best spot” spectrum is meaningless.
• Sheet resistance — Measured by four-point probe at multiple locations. High-quality monolayer CVD graphene achieves 125–500 Ω/sq. If a supplier claims <100 Ω/sq for monolayer, demand the measurement method — this approaches theoretical limits and is rarely achieved on transferred films.
• Coverage — Percentage of substrate area with continuous graphene. Tears, pinholes, and incomplete growth are common after transfer. Optical microscopy or SEM images at ≥100x provide a quick assessment.
• Transfer residue — PMMA residue from wet transfer degrades performance. Ask whether the supplier uses a PMMA-free or clean-transfer process, and whether post-transfer cleaning is performed.

For Powders (FLG, GNP, GO, rGO)

When procuring bulk graphene powders or dispersions, request:

• Layer-count distribution — Not an average, but a distribution. “Average 5 layers” could mean mostly monolayer with some thick flakes, or it could mean uniformly 5 layers — these perform very differently. AFM or TEM measurements of ≥50 flakes are the standard method.
• Lateral size distribution — Measured by dynamic light scattering (DLS) or image analysis. Report D10, D50, and D90 values.
• BET surface area — Measured by nitrogen adsorption. Theoretical monolayer graphene has a BET of ~2,630 m²/g; commercial FLG typically measures 50–500 m²/g. BET below 50 m²/g suggests thick, low-aspect-ratio material.
• C:O atomic ratio — Measured by X-ray photoelectron spectroscopy (XPS). For FLG and GNP, C:O should exceed 20:1 (>95% carbon). For GO, C:O is typically 1.5–3:1. For rGO, C:O of 8–15:1 indicates moderate reduction. This ratio is the single fastest indicator of material type.
• Electrical conductivity — Measured on compressed pellets or cast films, reported in S/m. Useful for comparing supplier claims.

Red Flags When Evaluating Suppliers

Over years of evaluating graphene materials, certain patterns reliably predict problematic suppliers:

No Raman data available. Raman spectroscopy is inexpensive, fast, and universally accepted. A supplier that cannot provide Raman spectra either has not characterized their product or does not want you to see the results. Walk away.

Only single-point Raman spectra. A single spectrum can be cherry-picked from the best spot on a sample. Demand mapped data or at minimum 10+ random-location spectra with statistics.

Claims of “99.9% purity” without specifying what was measured. Elemental purity (carbon content by combustion analysis) tells you nothing about layer count, defect density, or graphene content. A block of graphite is 99.9% carbon.

No independent characterization. Supplier-generated data should be verified by requesting a sample for third-party testing. If a supplier refuses to provide samples, that is itself a red flag.

Price dramatically below market. GNP powder at $5/kg exists, but it is almost certainly expanded graphite with creative marketing. If the price seems too good to be true for the claimed specification, it is.

“Graphene” used as a singular term. Sophisticated suppliers specify exactly what they sell — monolayer CVD on copper, FLG powder with D50 of 2 μm and 3–5 layers, GO dispersion at 4 mg/mL in water. Vague labeling suggests vague product.

Product Forms at a Glance

Procurement Checklist

Use this checklist before finalizing any graphene purchase above sample quantities:

1. Define your requirement precisely.

• Application identified (composite, coating, device, etc.)
• Required graphene form specified (CVD film, FLG, GNP, GO, rGO)
• Performance target quantified (e.g., “10% tensile improvement” or “<300 Ω/sq sheet resistance”)

2. Request characterization data.

• Raman spectroscopy (mapped for films, multi-point for powders)
• Layer-count distribution (AFM or TEM for powders; Raman mapping for films)
• Lateral size or area coverage data
• For powders: BET surface area and C:O ratio (XPS)
• For films: sheet resistance (four-point probe) and optical coverage

3. Evaluate the supplier.

• Independent characterization or Graphene Council verification available
• Supplier specifies exact product form, not just “graphene”
• Named customers or published application data available
• Consistent batch-to-batch quality documentation
• Willingness to provide samples for your own testing

4. Test before committing.

• Sample received and tested in your actual application (not just characterized)
• Performance meets your quantified target from step 1
• Second batch requested to verify consistency
• Pricing confirmed at production volume (not research-catalog pricing)

5. Establish ongoing quality control.

• Incoming inspection protocol defined (minimum: Raman spot-check per batch)
• Specification sheet agreed with supplier, including rejection criteria
• Alternative supplier identified for supply chain resilience

The graphene supply chain is maturing rapidly, and high-quality material is available from reputable suppliers at commercially viable prices. The key is knowing exactly what you need, insisting on data over claims, and testing before committing. The cost of proper due diligence is trivial compared to the cost of a failed development program built on mislabeled material.

This article is part of the Standards & Safety series on Graphene Guide. For an introduction to graphene types, see What Is Graphene?. For pricing context, see The Real Graphene Market. For definitions of terms, see the Graphene Glossary.