Photocatalytic Water Purification Patent Landscape 2026
The photocatalytic water purification field is in a sustained growth phase, with Chinese institutions and academic filers dominating a fragmented but expanding corpus. Nitto Denko leads among corporate filers, while university entrants from India, China, and France are driving the most recent acceleration.
Fragmented field led by a corporate pioneer and a long tail of academic filers
Nitto Denko Corp holds the top position with 50 patent families, ahead of Shoolini University of Biotech & Management Sciences (35), Guangdong University of Technology (33), Hohai University (32), CNRS (32), and Jiangsu University (32). The top-ranked filer’s lead over the next tier is modest, signaling a field where no single entity commands a decisive share.
The top five filers account for 12% of the combined output of the hundred largest filers — a low concentration figure that confirms the field is broadly contested. There is no dominant corporate bloc; academic and research institutions fill most of the top-20 slots.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | Nitto Denko Corporation | 50 | |
| 2 | Shoolini University OF BIOTECH & MANAGEMENT SCI | 35 | |
| 3 | Guangdong University of Technology | 33 | |
| 4 | Hohai University | 32 | |
| 5 | French National Centre for Scientific Research (CNRS) | 32 | |
| 6 | Jiangsu University | 32 | |
| 7 | Madan Mohan Malaviya University of Technology | 32 | |
| 8 | Changzhou University | 30 | |
| 9 | HARBIN UNIV OF SCI & TECH | 29 | |
| 10 | Toto Ltd | 26 |
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 11 | Advanced Materials JTJ | 26 | |
| 12 | Fuzhou University | 25 | |
| 13 | KUNMING UNIV OF SCI & TECH | 25 | |
| 14 | Suzhou University | 24 | |
| 15 | SHAANXI UNIV OF SCI & TECH | 23 | |
| 16 | Hefei University of Technology | 23 | |
| 17 | University of Jinan | 22 | |
| 18 | Averett Devron R | 22 | |
| 19 | Shandong University | 22 | |
| 20 | Qilu University of Technology (Shandong Academy of Sciences) | 21 |
Nitto Denko’s position as the sole large-scale industrial leader suggests corporate filers have not yet consolidated around this technology at scale. For industrial entrants, the absence of a dominant corporate cluster reduces the risk of being locked out by dense cross-licensing, but also signals that commercialization pathways remain early-stage.
The most recent 18–24 months of filings are under-represented due to standard patent publication lag; apparent volume in 2025–2026 should be read as a floor, not a ceiling. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Rising annual filings with a core anchored in catalysis and wastewater treatment
The filing trend shows consistent growth from 2017 onward, with the technology mix heavily concentrated in two adjacent IPC classes that together define the field’s technical core.
Annual filing trend
Annual families grew from 183 in 2017 to 500 in 2024, with the multi-year window up 31%. The 2025–2026 bars are truncated by publication lag and should not be read as a plateau or decline; the lifecycle evidence confirms the field is still in a growth stage.
↗ Hover for values · click a bar to ask EurekaTechnology composition
B01J (chemical/physical processes and catalysis) and C02F (water and wastewater treatment) together account for the overwhelming majority of classified records, confirming that photocatalysis and direct water treatment remain the dominant technical routes. Smaller but notable clusters appear in B01D (separation/filtration), C01G (metal compounds), B82Y (nanotechnology), and A61L (sterilisation and disinfection), pointing to adjacent application spaces.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Photocatalytic degradation and removal of imidaclo…
There is disclosed magnetic covalent organic frameworks (COFs) functionalized with Fe<sub>3</sub>O<sub>4 </sub>nanoparticles (Fe<sub>3</sub>O<sub>4</sub>@HMN-COF, Fe<sub>3</sub>O<sub>4</sub>@MAN-COF, and Fe<sub>3</sub>O<sub>4</sub>@SIN-COF) for the efficient removal and degradation of imidacloprid (IMI) from aqueous solutions. These COFs, incorporating… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Photocatalytic oxidation of organics using a porou… | 210 |
| 2 | Method and apparatus for destroying organic compou… | 180 |
| 3 | Nanoparticulate titanium dioxide coatings, and pro… | 166 |
| 4 | Nanoparticulate titanium dioxide coatings, and pro… | 156 |
| 5 | Photocatalytic treatment of water for the preparat… | 149 |
| 6 | Photocatalytic treatment of water | 144 |
| 7 | Photocatalytic oxidation of organics using a porou… | 124 |
| 8 | Doped carbonaceous materials for photocatalytic re… | 117 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the competitive structure means for R&D prioritisation
China-centric jurisdictional footprint creates both opportunities and risks for new entrants and incumbents alike.
Growth stage: annual filings still rising
The field is classified as Growth, with annual filings rising and a 31% increase in the recent window. The lifecycle evidence confirms this is not a post-peak slowdown — the field has not eased from a prior peak. R&D investment made now is entering a still-expanding competitive space rather than a saturated one, though the accelerating pace of new entrants raises the bar for differentiation.
Growth stageLow concentration: no corporate bloc controls the field
With the top five filers holding only 12% of the hundred largest filers’ combined output, and the leading applicant at just 50 patent families, there is no dominant player capable of broadly blocking competitors through portfolio density alone. The top 20 is populated primarily by universities and public research bodies, which typically license rather than enforce aggressively. This structural openness favours new industrial entrants with focused, high-quality filings.
FragmentedCNRS anchors the most active co-filing network
The French National Centre for Scientific Research (CNRS) is the most prolific co-applicant hub, with documented co-filing relationships spanning Claude Bernard Lyon 1 University (11 joint families), University of Strasbourg (8), Ahlstrom (7), Thermal Industries (7), École Polytechnique (7), and CY Cergy Paris University (6). This network signals that Europe’s academic-industrial bridge for photocatalysis is centred on French institutions. Engaging or partnering with CNRS-affiliated labs offers a credible route into the European ecosystem.
CNRS-led networkChina dominates filing volume; India and the US are secondary hubs
China accounts for the largest share of patent records by jurisdiction, followed by India and the United States. WIPO and EPO filings together indicate meaningful international protection activity. Japan and South Korea have modest but established footprints reflecting industrial filers like Nitto Denko and Toto. The geographic weight in China and India reflects where academic research is most active; industrial players seeking commercially enforced rights in developed markets should prioritise PCT and EPO routes, which remain proportionally underfiled relative to Chinese volume.
China-centricGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| French National Centre for Scientific Research (CNRS) | Claude Bernard Lyon 1 University | 11 |
| French National Centre for Scientific Research (CNRS) | University of Strasbourg | 8 |
| French National Centre for Scientific Research (CNRS) | Ahlstrom | 7 |
| French National Centre for Scientific Research (CNRS) | Thermal Industries | 7 |
| French National Centre for Scientific Research (CNRS) | École Polytechnique | 7 |
| French National Centre for Scientific Research (CNRS) | CY Cergy Paris University | 6 |
| French National Centre for Scientific Research (CNRS) | IFP Energies nouvelles | 4 |
| French National Centre for Scientific Research (CNRS) | Paris-Saclay University | 3 |
| French National Centre for Scientific Research (CNRS) | French Alternative Energies and Atomic Energy Commission (CEA) | 3 |
| French National Centre for Scientific Research (CNRS) | École Normale Supérieure de Lyon | 2 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Nitto Denko leads industrially; academic entrants are accelerating
The top of the ranking is split between one established industrial leader and a cohort of university filers — several of which entered only in the most recent filing window.
Nitto Denko Corp
Nitto Denko leads the corpus with 50 patent families, concentrated in B01J 35 (catalyst form factors), B01J 23 (supported metal catalysts), and B01J 37 (catalyst preparation methods) — a technically deep, process-oriented portfolio that reflects industrial manufacturing intent rather than basic research. Their momentum data is not flagged as a new entrant, indicating an established, sustained filing cadence rather than a recent spike.
families: 50Madan Mohan Malaviya University of Technology
With 32 patent families and a new-entrant trend flag, Madan Mohan Malaviya University of Technology has entered the top tier entirely within the recent filing window, with its 24 recent-period families making it the most active new academic entrant by volume. Its focus spans B01J 35, B01J 31, and B01J 27 — a catalyst-centric profile consistent with photocatalyst synthesis research rather than applied water treatment engineering.
families: 32| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Jiangsu University | 3 | ▲ new entrant |
| Changzhou University | 18 | ▲ +64% |
| Guangdong University of Technology | 11 | ▲ new entrant |
| Shoolini University OF BIOTECH & MANAGEMENT SCI | 20 | ▲ new entrant |
| Hohai University | 7 | ▲ new entrant |
| Madan Mohan Malaviya University of Technology | 24 | ▲ new entrant |
| French National Centre for Scientific Research (CNRS) | 3 | ▲ new entrant |
| Harbin University of Science and Technology | 22 | ▲ new entrant |
Under-served branches adjacent to the photocatalysis core
Several IPC classes sit at the edge of the dominant B01J–C02F core with materially lower filing density, suggesting areas where the technical adjacency is clear but dedicated IP coverage is sparse.
A61L · Sterilisation and disinfection
A61L accounts for 149 records — roughly 2% of classified output — despite photocatalytic disinfection being a technically well-established mechanism for pathogen inactivation in drinking water and medical-grade water systems. The sparse coverage relative to the core C02F class suggests that applicants are framing their work around industrial wastewater rather than potable or medical water quality. An entrant with UV-LED or solar-driven photocatalytic disinfection claims anchored in A61L could build a differentiated position with limited direct competition from the existing dense clusters.
Search this in Eureka →B82Y · Nanotechnology applications
B82Y holds 278 records — approximately 3% of classified output — even though nanostructured photocatalysts (TiO2 nanoparticles, graphene composites, quantum dots) are among the most-researched material classes in the academic literature reflected in the top-cited patents. The gap between research intensity and dedicated nanotechnology IP classification may indicate that applicants are filing under B01J rather than cross-tagging into B82Y, creating a potential freedom-to-operate window for claims specifically directed at nano-enabled photocatalytic architectures and their water-treatment performance.
Search this in Eureka →How leading filers differ by technology route
Route coverage across the main technology branches in the current evidence set.
| Player | B01J 35 · Chemical/physical processes & catalysis | C02F 1 · Water & wastewater treatment | C02F 101 · Water & wastewater treatment | B01J 37 · Chemical/physical processes & catalysis | B01J 23 · Chemical/physical processes & catalysis |
|---|---|---|---|---|---|
| Changzhou University | Strong · 30 | Strong · 35 | Strong · 33 | Moderate · 11 | Absent |
| Nitto Denko Corporation | Strong · 49 | Absent | Absent | Moderate · 24 | Strong · 31 |
| Shoolini University of Biotechnology and Management Sciences | Strong · 30 | Strong · 30 | Strong · 24 | Absent | Moderate · 10 |
| Jiangsu University | Strong · 28 | Strong · 30 | Strong · 25 | Absent | Moderate · 10 |
| Guangdong University of Technology | Strong · 26 | Strong · 24 | Strong · 23 | Strong · 14 | Absent |
| Harbin University of Science and Technology | Strong · 28 | Strong · 21 | Strong · 18 | Moderate · 10 | Absent |
| Qilu University of Technology (Shandong Academy of Sciences) | Absent | Strong · 27 | Strong · 20 | Absent | Moderate · 13 |
Frequently asked questions
The corpus in scope covers 3,043 patent families. Filing volume has grown 31% in the recent window, with annual families reaching 500 in 2024 before publication lag compresses the most recent counts.
Nitto Denko Corp leads with 50 patent families, making it the only large industrial filer in the top tier. The next cluster — Shoolini University (35), Guangdong University of Technology (33), Hohai University (32), CNRS (32), and Jiangsu University (32) — are all academic or public research bodies.
The field is fragmented. The top five filers account for only 12% of the combined output of the hundred largest filers, and no corporate group has built a blocking position. New industrial entrants face a relatively open landscape, particularly in jurisdictions outside China.
China is the leading jurisdiction by patent records, followed by India and the United States. WIPO (PCT) and the EPO each have meaningful but smaller footprints, suggesting that international protection strategies beyond China and India are still underdeveloped relative to the volume of underlying research.
CNRS is the most active co-filer, with joint patent families involving Claude Bernard Lyon 1 University (11 families), University of Strasbourg (8), Ahlstrom (7), Thermal Industries (7), École Polytechnique (7), and CY Cergy Paris University (6), among others. This makes the French academic-industrial network the most visible collaborative cluster in the corpus.
A61L (sterilisation and disinfection) and B82Y (nanotechnology applications) stand out as branches with plausible technical connection to photocatalytic water purification but relatively sparse dedicated coverage — 149 and 278 records respectively — compared with the dominant B01J and C02F classes. B01D (separation processes) and C01G (metal compounds) are also observably lower-density branches within the corpus.
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Disclaimer. This page is generated from PatSnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
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