Neptunium

Neptunium (Np) — 10-Year Trends

As of 2026-09-25 · the last 10 years

Research intensity has fallen to about 26% of the element's own all-time peak, a level reached after a steady decline over the decade.

Research intensity ran from about 35% of the element's own all-time peak in 2016 to about 26% in 2026 — a steady decline, and the all-time peak (1964) lies before this window. Over the same span its share of research attention across all elements fell. Among the 118 elements, neptunium has a mid-sized research literature.

The number of papers involving the element rose from about 274 in 2016 to about 354 in 2025 (1.29x). That is slower than the literature as a whole grew over the same years, so the element lost ground in the wider body of research even as its own count rose.

The largest research community is Neptunium Separation and Redox Chemistry with Uranium, which accounts for about 44% of the element's recent research. This work focuses on neptunium's redox behavior and its separation from uranium and plutonium using nitric acid and ionic liquid extraction. Neptunium is a minor presence in this much larger community, appearing in about 2% of its papers. The community's share has remained steady over the last two five-year periods. A key paper from this group, "The role of the 5f valence orbitals of early actinides in chemical bonding" (2017), has been cited over 220 times, while more recent work such as "Preparation of Neptunyl and Plutonyl Acetates To Access Nonaqueous Transuranium Coordination Chemistry" (2024) has been cited about 22 times.

The second major area is Neptunium Transmutation in Water Reactor Fuel Cycles, representing about 23% of recent research. These studies examine the transmutation of neptunium and other minor actinides within pressurized water reactor metal fuel systems. Here, neptunium is also a minor presence, involved in about 1% of the community's papers. Its share of neptunium research has been steady. The most impactful recent work in this area is "Optimal Neutron Spectrum Database for In‐reactor 238 Pu Production" (2025), which has been cited about 28 times.

The third significant community is Neptunium Separation from Uranium and Plutonium Streams, holding about 20% of the element's recent research. This group investigates solvent extraction and liquid membrane techniques to isolate neptunium from spent nuclear fuel. Neptunium is a minor presence in this community as well, appearing in about 1% of its papers. While its share has been classified as steady, it has slightly decreased from 24.3% in the previous period to 19.6% now. A notable paper in this field, "Microplastics and disposable face masks as “Trojan Horse” for radionuclides pollution in water bodies – A review with emphasis on the involved interactions" (2023), has been cited about 32 times.

The remaining 14% of neptunium research is distributed among other smaller communities. Overall, the composition of neptunium research has remained relatively stable, with the separation and redox chemistry community maintaining its lead, while the transmutation and separation-from-streams communities hold consistent but slightly shifting shares.

For a deeper look at the current state of neptunium research, see the Last 12 Months and Executive Brief reports.