Functional Titanium Dioxide: Photocatalytic, Nano, Antimicrobial & Conductive Grades — Supply Chain Overview
Functional TiO₂ grades command a 5–20x price premium over pigment TiO₂, driven by controlled crystal phase, sub-30 nm particle sizing, and surface-engineered chemistry.
Contents
| 5–20× | <30 nm | >200 m²/g |
|---|---|---|
| Price premium vs pigment TiO₂ | Particle size, nano grades | BET surface area, photocatalytic grade |
Photocatalytic Anatase TiO₂ — Air Purification & Self-Cleaning Surfaces
Photocatalytic TiO₂ generates hydroxyl radicals under UV (λ < 387 nm), oxidising organic pollutants, bacteria, and VOCs on contact. SEMITECH's grade delivers BET ≥ 200 m²/g, anatase purity > 99%, and primary particle size 10–20 nm. Applications include HVAC filter coatings, ceramic tile glazes, architectural glass, and air-purification membranes.
- Phase — Anatase > 99%; no rutile contamination
- BET — ≥ 200 m²/g (ISO 9277)
- Particle size — D50 10–20 nm primary; agglomerate D50 < 200 nm
- Key markets — Indoor air purification, self-cleaning glass, anti-fouling coatings, photovoltaic anti-reflective layers
Nano Anatase & Nano Rutile TiO₂ — UV Absorption for Cosmetics and Coatings
Nano-scale TiO₂ blocks UV without visible whitening below ~50 nm. Nano anatase (10–25 nm) absorbs strongly in UVA for transparent sunscreen formulations. Nano rutile (15–30 nm) extends into UVB with superior photostability for automotive clear coats. Both grades are SiO₂/Al₂O₃ surface-treated to prevent photocatalytic degradation of the matrix.
- Anatase D50 — 10–25 nm; optimal UVA transparency
- Rutile D50 — 15–30 nm; broader UV coverage
- Surface treatment — SiO₂ or Al₂O₃ at 3–8 wt%
- Price sensitivity — Tracks TiCl₄ spot prices
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Antimicrobial Ag-TiO₂ — Visible-Light Activated Silver-Doped Titanate
Silver doping narrows the band gap toward visible light (λ < 550 nm) via plasmonic resonance, enabling ROS generation under fluorescent or LED illumination. Achieves JIS Z 2801 > 2 log reduction against E. coli and S. aureus at 1,000 lux. Applications include hospital coatings, food-contact packaging, and antimicrobial textiles.
- Ag loading — 0.5–2.0 wt% (ICP-OES)
- Test standard — JIS Z 2801; ISO 22196
- Cost driver — Silver metal is 60–70% of variable cost
Conductive ATO-TiO₂ — Antimony Tin Oxide for ESD Coatings & Transparent Electrodes
ATO (SnO₂ + 5–15 mol% Sb₂O₃) delivers volume resistivity 10²–10⁴ Ω·cm in a transparent package. On TiO₂ carriers, it enables ESD-safe clear coats for electronics packaging and conductive primers. Sheet resistance is tunable from 10³ to 10⁶ Ω/sq by varying ATO loading (10–40 wt%) and film thickness (0.5–3 µm).
- Resistivity — 10²–10⁴ Ω·cm bulk
- ATO composition — SnO₂ + 5–15 mol% Sb₂O₃; D50 15–40 nm
- Optical — Transmission > 85% at 550 nm
- Supply risk — Antimony sourced 90% from China
Functional TiO₂ Grade Comparison — Buyer Specification Reference
| Grade | Phase | D50 (nm) | BET (m²/g) | Key Spec | Primary Application | Top Supply Risk |
|---|---|---|---|---|---|---|
| Photocatalytic Anatase | Anatase ≥99% | 10–20 | ≥200 | Hydroxyl radical yield | Air purification, self-cleaning glass | TiCl₄ reactor capacity |
| Nano Anatase | Anatase | 10–25 | 80–150 | UV transparency @ <400 nm | Sunscreen, UV-cure coatings | TiCl₄ spot price |
| Nano Rutile | Rutile | 15–30 | 40–80 | UVA+UVB absorption, photostability | Auto clear coat, plastic UV stab | TiCl₄ + surface treatment cost |
| Ag-TiO₂ | Anatase + Ag° | 20 (host) | 60–120 | Log reduction ≥2 (JIS Z 2801) | Hospital coatings, food packaging | Silver spot price volatility |
| ATO-TiO₂ | SnO₂/Sb (on TiO₂) | 15–40 (ATO) | 30–60 | Volume resistivity 10²–10⁴ Ω·cm | ESD coatings, conductive primers | Antimony trioxide supply/price |
All five grades are produced via the chloride route or post-synthesis doping, tying landed cost to TiCl₄ and specialty dopant price cycles. Buyers should model ±20% raw material cost variance.
FAQ
+What is the difference between functional TiO₂ and standard pigment TiO₂?
Functional TiO₂ is engineered for a specific mechanism — photocatalysis, UV absorption, antimicrobial activity, or conductivity — not optical whiteness. Functional grades are sub-30 nm, high-BET, phase-pure, and surface-treated, costing 5–20x more than commodity pigment.
+Can photocatalytic TiO₂ work under visible light without doping?
No. Undoped anatase requires UV below 387 nm (band gap ~3.2 eV). For visible-light activity, dopants such as Ag, N, or C are needed. SEMITECH's Ag-TiO₂ is formulated for visible-light antimicrobial applications at 1,000 lux.
+What BET surface area should I specify for photocatalytic coatings?
BET ≥ 150 m²/g as a floor; ≥ 200 m²/g preferred for high-throughput air purification. Below 100 m²/g, photocatalytic efficiency drops sharply.
+How does antimony supply risk affect ATO-TiO₂ pricing?
China controls ~90% of antimony mine supply. Sb₂O₃ has traded $6,500–$12,000/mt over two years, translating to $8–15/kg moves in finished ATO-TiO₂. Buyers above 500 kg/month should negotiate quarterly price bands.
+Which grade suits transparent UV-blocking cosmetic formulations?
Nano anatase (D50 10–25 nm, SiO₂/Al₂O₃ treated). Surface treatment is mandatory to suppress photocatalytic degradation of co-formulated UV filters.
+What ATO loading achieves ESD-safe performance (10⁶ Ω/sq)?
20–30 wt% ATO in clear binder at 1–2 µm DFT, verified by 4-point probe (ASTM D257). Below 15 wt%, resistivity climbs above 10⁹ Ω/sq.