Research method
Transmission Electron Microscopy (TEM)
24 studies
Transmission electron microscopy forms an image (and often a diffraction pattern) from electrons that have passed through a thin specimen. Diameters, lattice fringes, selected-area diffraction and cryo-TEM pitch measurements report local size and order at the nanometre scale. In this library TEM is used to size silver and platinum particles, to check polymer vesicles after a SAXS run, to measure amyloid fibril helical pitch, and to watch pyrite cubes grow from clusters — each time on a small counted set of objects, not on the whole flask.
Materials chemists reach for TEM when the question is how big, how crystalline, or how the morphology evolved. It answers 'what does this thin region look like at nanometre resolution?' Its main limitation is sampling: tens of particles, a dried grid, or a reconstructed catalyst after electrochemistry need not represent the working ensemble, and TEM length scales are not SEM length scales.
Studies
24
Findings
6
7 supporting · 0 challenging · 0 qualifying citations
Open tensions
2
Currently
What we know
- TEM of a glycerol/PVP silver synthesis, counting ~50 particles, tracks a solvent knob that UV-vis only sees as SPR. Up to ~60% glycerol, particles stay ultra-small (<10 nm) with a stable 410–450 nm plasmon; above ~70–80% glycerol, SPR and size rise, spanning about 10–160 nm (extremes 1.8 nm and 159 nm). High glycerol viscosity also complicates DLS, so TEM is doing work that a single hydrodynamic diameter cannot.
- Stirring time is another TEM-readable size knob. Glutathione-capped Ag at 60 °C grows TEM diameters 3.20, 4.83 and 6.19 nm at 36, 48 and 72 h as fcc metal forms and SPR appears at 344–354 nm. Blackberry-leaf Ag is much larger by TEM (50–120 nm) with SPR at 449 nm — same metal, different length scale, both still images of dried particles.
- On a fuel-cell catalyst, TEM size splits into two populations whose electrochemistry is not equal. Heat treatment of 1.8 nm sputtered Pt on PEG/Vulcan carbon yields a bimodal 2.5 ± 0.8 nm and 6.7 ± 1.8 nm distribution; the larger particles dominate ORR activity. TEM here is the size histogram that rotating-disk voltammetry then ranks.
- After a ~2 mL in situ SAXS PISA run, TEM is the morphology check, not the nucleation clock. Micelles nucleate at 9–10 min by SAXS; worms appear near PHPMA DP 134 after 28–29 min; vesicles reach Dv = 227 ± 16 nm. HPMA conversion exceeds 99% within 80 min (GPC Mn 51 200 g mol⁻¹, Đ = 1.25). The SAXS clock is faster than the lab ¹H NMR rate jump.
- Cryo-TEM pitch can distinguish two amyloid polymorphs that mixed nucleation might have been expected to scramble. Aβ40 fibrils have a helical half-pitch of 162 nm versus 31 nm for Aβ42; first fibrils are Aβ42 (<13% Aβ40). Cross-seeding is weak versus self-seeding. Atomic mixed-oligomer structures are not solved.
Largest unresolved question
TEM and SEM are not interchangeable length scales. The glycerol silver paper uses TEM (~50 particles) for ultra-small (<10 nm) objects and SEM for larger particles as glycerol exceeds ~70–80% and sizes reach tens to 159 nm. Quoting 'electron microscopy showed 10 nm particles' without which microscope and which glycerol fraction mixes those regimes.
Procedure
How it works
The main stages of the method. Specific protocols and analysis choices vary between studies.
Prepare a thin specimen
Electrons only transmit through a thin region — a nanoparticle drop-cast on a grid, a microtomed slice, or a cryo film. Drying, staining, and which patch the operator photographs are already a sample, not a view of the whole flask.
Pass electrons through the sample
A high-energy beam is focused through the specimen in vacuum. Contrast comes from how much the local thickness, density, and diffraction scatter or absorb those electrons.
Form an image or a diffraction pattern
The transmitted electrons can be imaged (bright field, lattice fringes) or selected-area diffracted. Cryo-TEM can also measure helical pitch on a frozen hydrated object. Each mode reports local size and order at the nanometre scale.
Count a small set of objects
Diameters, cube edges, or vesicle walls are measured on tens to hundreds of particles. That distribution is what the grid held and what was photographed; DLS or a bulk assay can disagree without either being 'wrong.'
Do not treat the micrograph as the working ensemble
TEM answers what this thin region looks like at nanometre resolution. A crystalline nanocube on the grid need not be the electrocatalyst after cycling, a TEM diameter is not by itself the activity-determining size, and TEM length scales are not SEM length scales.
Common misconceptions
A TEM image is the whole sample.
Glycerol Ag sizes rest on ~50 particles; DLS at high glycerol is compromised by viscosity. GSH-capped Ag still grows more polydisperse with time. A grid selects what dried and what the operator photographed.
If TEM shows a crystalline nanocube, that crystal is the electrocatalyst.
NiFeS₂ porous cubes are pre-catalysts: after CVs the active material is amorphous S-doped metal (oxy)hydroxide. η₁₀ < 260 mV is measured on the reconstructed film, and a GCE η₁₀ is not a device metric.
Particle diameter from TEM is the quantity that determines activity.
Bimodal Pt (2.5 and 6.7 nm) is both visible by TEM; ORR is dominated by the larger 6.7 ± 1.8 nm set. Size is necessary characterisation, not a substitute for a kinetic ranking.
Related
Claim ledger
What the evidence shows
Drawn from 24 studies in this library. Mix labels say which citation roles are present; they are not a strength score. Supports means evidence for a finding; Challenges means evidence against a stated position; Qualifies marks scope.
TEM of a glycerol/PVP silver synthesis, counting ~50 particles, tracks a solvent knob that UV-vis only sees as SPR. Up to ~60% glycerol, particles stay ultra-small (<10 nm) with a stable 410–450 nm plasmon; above ~70–80% glycerol, SPR and size rise, spanning about 10–160 nm (extremes 1.8 nm and 159 nm). High glycerol viscosity also complicates DLS, so TEM is doing work that a single hydrodynamic diameter cannot.
Stirring time is another TEM-readable size knob. Glutathione-capped Ag at 60 °C grows TEM diameters 3.20, 4.83 and 6.19 nm at 36, 48 and 72 h as fcc metal forms and SPR appears at 344–354 nm. Blackberry-leaf Ag is much larger by TEM (50–120 nm) with SPR at 449 nm — same metal, different length scale, both still images of dried particles.
- Stirring time sets GSH-capped silver nanoparticle size
- Blackberry-leaf silver nanoparticles against plant pathogens
Study Role Design N Population Outcome Stirring time sets GSH-capped silver nanoparticle size Supports OtherTime-dependent glutathione-capped AgNP growth tracked by SPR/TEM/XRD Nanomaterial synthesis kinetics — no sample N Silver nanoparticles prepared with glutathione at 60 °C Stirring-time dependence of particle diameter and SPR Blackberry-leaf silver nanoparticles against plant pathogens Supports Animal / in-vitroPlant-extract AgNP synthesis with antibacterial titration against plant pathogens and DPPH assays Materials/antimicrobial assay study — no sample N Ralstonia solanacearum and Erwinia carotovora cultures exposed to Rubus-derived AgNPs Pathogen inhibition and antioxidant activity of biogenic AgNPs On a fuel-cell catalyst, TEM size splits into two populations whose electrochemistry is not equal. Heat treatment of 1.8 nm sputtered Pt on PEG/Vulcan carbon yields a bimodal 2.5 ± 0.8 nm and 6.7 ± 1.8 nm distribution; the larger particles dominate ORR activity. TEM here is the size histogram that rotating-disk voltammetry then ranks.
After a ~2 mL in situ SAXS PISA run, TEM is the morphology check, not the nucleation clock. Micelles nucleate at 9–10 min by SAXS; worms appear near PHPMA DP 134 after 28–29 min; vesicles reach Dv = 227 ± 16 nm. HPMA conversion exceeds 99% within 80 min (GPC Mn 51 200 g mol⁻¹, Đ = 1.25). The SAXS clock is faster than the lab ¹H NMR rate jump.
Cryo-TEM pitch can distinguish two amyloid polymorphs that mixed nucleation might have been expected to scramble. Aβ40 fibrils have a helical half-pitch of 162 nm versus 31 nm for Aβ42; first fibrils are Aβ42 (<13% Aβ40). Cross-seeding is weak versus self-seeding. Atomic mixed-oligomer structures are not solved.
TEM/SAED of a pre-catalyst can disagree with the working catalyst. Fe-doped NiFeS₂ pyrite mesocrystals grow as 40–50 nm nearly single-crystalline porous cubes from <2 nm clusters at 180 °C, with η₁₀ < 260 mV versus 351 mV for NiS₂. After CVs the real OER catalyst is an amorphous S-doped metal (oxy)hydroxide; Fe helps retain S. The cubes TEM imaged are not the surface that evolves oxygen.
Debates
Tensions and limits
Some items are genuine disagreements on the same question. Others mark different assays, populations, or outcomes.
TEM and SEM are not interchangeable length scales. The glycerol silver paper uses TEM (~50 particles) for ultra-small (<10 nm) objects and SEM for larger particles as glycerol exceeds ~70–80% and sizes reach tens to 159 nm. Quoting 'electron microscopy showed 10 nm particles' without which microscope and which glycerol fraction mixes those regimes.
TEM and SEM are not interchangeable length scales. The glycerol silver paper uses TEM (~50 particles) for ultra-small (<10 nm) objects and SEM for larger particles as glycerol exceeds ~70–80% and sizes reach tens to 159 nm. Quoting 'electron microscopy showed 10 nm particles' without which microscope and which glycerol fraction mixes those regimes.
PaperFren reads this as a limit on how far one study travels — different assays, populations, or outcomes — not a forced fight between papers.
A TEM image of the as-made solid can be characterisation while the mechanism lives elsewhere. Pyrite mesocrystal cubes (40–50 nm, SAED nearly single-crystalline) reconstruct into amorphous (oxy)hydroxide under OER CVs; SAXS, not TEM, clocks PISA nucleation at 9–10 min. Treating the first image as the operating structure is the disagreement between those papers and a simple 'TEM showed the catalyst/morphology' sentence.
A TEM image of the as-made solid can be characterisation while the mechanism lives elsewhere. Pyrite mesocrystal cubes (40–50 nm, SAED nearly single-crystalline) reconstruct into amorphous (oxy)hydroxide under OER CVs; SAXS, not TEM, clocks PISA nucleation at 9–10 min. Treating the first image as the operating structure is the disagreement between those papers and a simple 'TEM showed the catalyst/morphology' sentence.
Study Role Design N Population Outcome Pyrite mesocrystals reconstruct into OER catalysts Supports OtherNiFeS2 pyrite mesocrystal growth and OER pre-catalyst evaluation Materials synthesis and electrocatalysis — no sample N Fe-doped NiS2 pyrite mesocrystals on GCEs OER overpotential and post-CV transformation to active (oxy)hydroxide Watching RAFT PISA grow spheres, worms, vesicles Supports OtherIn situ SAXS of aqueous RAFT HPMA polymerization from a PGMA45 macro-CTA ~2 mL SAXS cell polymerization tracking — no sample N Aqueous RAFT polymerization forming micelles, worms, and vesicles Time-resolved nucleation and morphological transitions during polymerization
PaperFren reads this as a limit on how far one study travels — different assays, populations, or outcomes — not a forced fight between papers.
Timeline
How understanding moved
Study years are when the paper was published. Evidence edits are dated changes to this page's claims. Explanations are when PaperFren added a Discovery — not a claim that the science happened that day.
2026
Concept page published
Transmission Electron Microscopy (TEM)
Change log
What changed
Dated edits to this page's evidence: studies added or removed from a claim, claims added or withdrawn, and new explanations tagged here. Coverage edits are distinct from reviewed research changes and corrections. Dates record PaperFren updates; study publication dates appear in the timeline.
- Coverage updated · Concept page published
Papers
24 studies in this library bear on Transmission Electron Microscopy (TEM), ordered by citations.
- Single-atom Co–N–C catalyzes nitroarene azo coupling
A self-supporting Co–N–C single-atom catalyst with a CoN4C8-1-2O2 site hydrogenatively couples nitroarenes to azo compounds.
- Aβ40 and Aβ42 make separate fibrils after mixed nuclei
In mixtures, Aβ42 fibrillizes first; elongation and secondary nucleation stay homospecific, so each peptide builds its own fibrils.
- Ir nanodendrites on ATO for acid OER
TTAB-grown Ir nanodendrites on mesoporous ATO outperform Ir black for oxygen evolution in acid and in a PEM electrolyzer.
- FeMn single-atom nanozyme dual-readout HER2 test
An etched FeMn–N–C nanozyme boosts peroxidase-like activity 2.03-fold and reports HER2 by electrochemistry and 808 nm photothermal readout.
- Single silver nanoparticles strip in many shots
SECCM impact transients show 10 nm Ag particles often dissolve in one spike, but larger ones leave, return, and only partly oxidize.
- Ultrathin porous CoP nanosheets drive HER
Phosphidation of Co3O4 yields sub-1.1 nm porous CoP sheets with exposed {200} facets and high HER mass activity.
- A MOF that releases CO with visible light
Post-synthetic Mn(CO)3 on a zirconium MOF (CORF-1) liberates carbon monoxide under low-intensity visible light, with crystal size from 260 nm to 1 mm setting the dose.
- Ten-gram grinding makes lanthanum coordination polymers
Manual grinding of LaCl3 with 5-sulfosalicylate and 8-hydroxyquinoline yields ternary CPs whose IR/XPS/MS match a chelated nanocomposite.
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- Carbon-coated nickel nanoparticles that make CO from CO2
N-doped carbon plus a carbon coat lets metallic Ni nanoparticles reach about 94% CO faradaic efficiency, suppressing hydrogen evolution.
- Pt TPE cages harvest light for cyclization
Self-assembled platinum–tetraphenylethene cages transfer energy to rhodamine B (up to 77% ΦET) and photocatalyze maleimide–aniline cyclization in water-rich solvent.
- Stirring time sets GSH-capped silver nanoparticle size
Glutathione reduces AgNO3 at 60 °C; longer stirring grows spherical Ag nanoparticles from about 3 to 6 nm.
- Watching RAFT PISA grow spheres, worms, vesicles
In situ SAXS shows PGMA45-PHPMA200 aqueous RAFT PISA nucleating in 9–10 min and finishing as ~227 nm vesicles.
- Gamma-made Ag–Se nanoparticles carrying cefotaxime
Radiolytic Ag, Se, and Ag–Se nanoparticles (about 11–21 nm) are characterized and loaded with cefotaxime for synergistic antimicrobial tests.
- Pore diameter flips ORR from kinetic to transport control
Narrower Pt–Ni nanozyme channels raise ORR activity at low overpotential by concentrating protons, but at high overpotential O2 reacts at the pore mouth.
- Pyrite mesocrystals reconstruct into OER catalysts
Oleylamine-grown (NiFe)S2 porous cubes form by cluster aggregation; Fe-doped samples reach η10 < 260 mV after converting to S-doped (oxy)hydroxides.
- Stibnite in carbon sheets stores sodium better
Natural Sb2S3 anchored on sulfur-doped carbon sheets delivers much higher reversible sodium-storage capacity and cycle retention than raw stibnite.
- NH4OH tunes silica dots from 20 to 500 nm
Varying ammonia in a Stöber synthesis sizes silica nanoparticles from 20 to 200 nm (then 500 nm with extra TEOS), enabling core–shell TAMRA–BHQ2 quenching studies over unusually long distances.
- Microwave phage carbons glow and sense Fe3+
M13 bacteriophage carbonized in a 700 W microwave gives fluorescent nanoparticles (QY 14.8%) that quench with Fe3+ down to an 8.0 μM LOD.
- Glycerol tunes silver nanoparticle size
Silver nitrate reduced in 10–100% glycerol with PVP at room temperature gives plasmonic Ag nanoparticles from ultra-small (~1.8 nm) up to ~160 nm.
- Blackberry-leaf silver nanoparticles against plant pathogens
Rubus fruticosus extract reduces Ag+ to 50–120 nm AgNPs (SPR 449 nm) that fully inhibit two phytopathogens at the highest dose.
- Plasmonic SiO2/TiO2 aerogels degrade RhB
Anatase TiO2 grown in silica aerogels, then Ag@Au nanoshells, adsorbs and photocatalyzes rhodamine B far better than TiO2 powder.
- Sputtering Pt onto PEG to make fuel-cell catalysts
Pt sputtered onto liquid PEG, then heat-transferred onto carbon, gives bimodal nanoparticles whose larger population drives ORR activity.
- Al3+ lights up Ag/Au clusters to sense fluoroquinolones
Dithioerythritol Ag/Au nanoclusters aggregate with Al3+ and then report ciprofloxacin, norfloxacin and enrofloxacin by ratiometric fluorescence down to a few nanomolar.
- Many silicatein mutants together make better nanoceria
Evolving silicatein for ceria biomineralization never yielded one champion sequence; mixed truncated mutants and intact catalytic-triad knockouts still mineralize, implying synergistic mosaicism.
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Questions
What is still open
TEM and SEM are not interchangeable length scales. The glycerol silver paper uses TEM (~50 particles) for ultra-small (<10 nm) objects and SEM for larger particles as glycerol exceeds ~70–80% and sizes reach tens to 159 nm. Quoting 'electron microscopy showed 10 nm particles' without which microscope and which glycerol fraction mixes those regimes.
A TEM image of the as-made solid can be characterisation while the mechanism lives elsewhere. Pyrite mesocrystal cubes (40–50 nm, SAED nearly single-crystalline) reconstruct into amorphous (oxy)hydroxide under OER CVs; SAXS, not TEM, clocks PISA nucleation at 9–10 min. Treating the first image as the operating structure is the disagreement between those papers and a simple 'TEM showed the catalyst/morphology' sentence.
Ask PaperFren about Transmission Electron Microscopy (TEM)
Study this conceptflashcards and short-answer questions
Why might two silver papers both 'use TEM' yet report 3.20–6.19 nm versus 50–120 nm particles without contradicting each other?
They are different syntheses. GSH stirring time at 60 °C grows small fcc particles (SPR 344–354 nm); blackberry-leaf reduction gives larger particles (SPR 449 nm). TEM reports the local diameter in each recipe, not a universal Ag size.
In the glycerol synthesis, when should you believe TEM over DLS, and when is SEM the better electron-microscopy choice?
At high glycerol, viscosity distorts DLS, so TEM of a limited particle count is the more direct size check for ultra-small (<10 nm) objects. Once glycerol exceeds ~70–80% and particles reach tens to ~160 nm, the paper uses SEM for the larger objects; TEM of ~50 particles is no longer the whole story.
SAXS says PISA micelles nucleate at 9–10 min and vesicles reach Dv = 227 ± 16 nm. What did TEM contribute that SAXS did not, and vice versa?
TEM (with DLS after the run) checks real-space sphere/worm/vesicle morphology. SAXS in the ~2 mL cell supplies the time-resolved nucleation and growth clock, which is faster than the lab ¹H NMR conversion jump. Neither alone is a full kinetic-plus-shape assignment.
Fe-doped pyrite mesocrystals are 40–50 nm cubes with η₁₀ < 260 mV. Why is it wrong to say TEM imaged the OER active site?
TEM/SAED describe the as-made mesocrystal. Post-CV spectroscopy shows reconstruction to amorphous S-doped (oxy)hydroxide, which is the working catalyst. The cube is a pre-catalyst morphology; Fe's role in the paper is helping retain sulfur during that reconstruction.