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Novel Quasi‑2D tellurium (Te) nanosheets developed offer an unusual approach to controlling magnetism and catalysis in a single material, facilitating indigenous solutions for sustainable hydrogen production impacting future clean‑energy production.

As devices shrink, traditional materials are becoming limited in their relevance due to instability and loss of functionality and scientists are looking for materials that can suit the changing needs. Recent predictions and experiments on 2D Te and telluride magnets suggested that breaking inversion symmetry and introducing strain could unlock spin‑orbit‑driven magnetism and ferroelectricity in elemental Te.

Building on this background, a team of scientists from the Institute of Nano Science and Technology (INST), Mohali, an autonomous institute of the Department of Science and Technology (DST) have found a way to develop a new nano-material called quasi‑2D α‑Te nanosheets in an emergent ferromagnetic state that can make future hydrogen‑producing electrolysers more energy‑efficient.

This is possible as the magnetoelectric control lowers the voltage needed to generate hydrogen and speeds up the reaction, reducing electricity use for green hydrogen production.

The procedure combines scalable liquid‑phase exfoliation, strain‑engineered lattice distortions, and advanced spin‑sensitive probes to explicitly track how unpaired surface spins emerge and furthermore how it can be manipulated.

Fig: Magnetic field‑induced hydrogen evolution on a 2D Te nanosheet. Under an applied magnetic field, unpaired surface spins on the α‑Te nanosheet generate hydrogen gas bubbles, with enhanced performance at higher fields.

INST scientist Prof. Dipankar Mandal and his PhD student Dalip Saini have shown that when bulk tellurium is exfoliated into quasi‑2D α‑Te nanosheets, the surface “unlocks” unpaired 5p electron spins that are otherwise quenched in bulk Te, giving rise to an emergent ferromagnetic state tied to surface strain and broken inversion symmetry.

This surface magnetism couples strongly with ferroelectricity to produce a giant magnetoelectric response, which the team harnessed to significantly boost the hydrogen evolution reaction (HER), demonstrating a single material that links multiferroicity, spintronics, and electrocatalysis.

This work published in Advanced Materials shows that an elemental 2D material, quasi‑2D α‑tellurium, can host unpaired surface spins that become ferromagnetically ordered and are directly controllable through strain and electric fields, rather than relying on transition‑metal ions or complex magnetic compounds.

It uniquely couples this surface ferromagnetism with ferroelectric and strong piezoelectric responses in the same few‑layer Te platform, and then demonstrates that this magnetoelectric coupling can be used to actively enhance hydrogen evolution catalysis. 

The work connects three areas-- spintronics, multiferroic nanoelectronics, and green hydrogen technologies, targeting applications in low‑power memory, smart sensors, and magnetoelectric‑driven water electrolysers.

The stability and flexibility of quasi‑2D α‑Te nanosheets make them promising for flexible, portable, and wearable energy and sensing technologies, potentially improving access to clean energy and real‑time health or environmental monitoring for the wider population.

Publication link: ITTEN

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