Every year, millions of tonnes of electronic waste pile up around the world, and printed circuit boards (PCBs) are among the trickiest parts to recycle. One big reason is bromine: flame retardants added to PCBs to prevent fires contain bromine compounds that, if handled carelessly during recycling, can release toxic fumes or contaminate water. Most current recycling methods either burn the boards (releasing pollutants) or use harsh chemical baths that generate hazardous wastewater.

This work introduces a cleaner alternative. Using a process called solvothermal treatment, where the PCBs are heated in a sealed vessel with carefully chosen solvents at moderate temperatures, the team was able to strip bromine out of end-of-life circuit boards without producing any liquid waste discharge. The phrase "zero-discharge" is key: nothing toxic goes down the drain. The bromine is captured in a controlled way, and the remaining materials (metals, glass fibres) can be recovered for further recycling.

In short, this study shows that we can safely de-brominate old electronics, closing a gap in the e-waste recycling chain and moving closer to a truly circular economy for electronic materials.

Reference:

Kummari, Shivaraj Kumar, Mississippi M. Bhunia, R. Ratheesh, Tiju Thomas, and Sreeram K. Kalpathy. "Debromination of End-of-Life Printed Circuit Boards through a Zero-Discharge Solvothermal Process." Journal of Cleaner Production (2026). https://doi.org/10.1016/j.jclepro.2026.148331

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This paper asks a provocative question: can the plastic waste from old electronics be reborn as functional sensors? Electronic waste contains large quantities of engineering-grade polymers, materials originally designed for durability, heat resistance, and electrical insulation. When electronics reach end of life, these polymers usually end up in landfills or incinerators.

The researchers explore whether these recycled e-waste polymers can instead be repurposed to build chemical and environmental sensors. The idea is compelling because these polymers already possess useful properties (chemical stability, good mechanical strength) and recycling them into sensors would simultaneously address two problems: e-waste accumulation and the need for affordable sensing platforms.

The study evaluates which e-waste polymers are most promising, what processing steps are needed to convert them into sensor-grade materials, and how their sensing performance compares to virgin (newly manufactured) polymers. It is both a technical roadmap and a call to action for the materials community to look at waste not as a problem, but as a resource.

Reference

Robert, Berly, Suvitha S. Kumar, Tiju Thomas, and Sreeram K. Kalpathy. "Can Recycled E-Waste Polymers Power the Future of Sensors?" Journal of Materials Chemistry A (2026). https://doi.org/10.1039/d5ta09015f 

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Lithium-ion batteries power everything from phones to electric cars, but lithium is expensive and geographically concentrated. Sodium, lithium's chemical cousin, is thousands of times more abundant (think: table salt) and far cheaper. The challenge is that sodium-based batteries have historically underperformed lithium ones in terms of energy density and cycle life.

Enter "high-entropy" materials: a relatively new design philosophy where five or more different metal elements are mixed together in roughly equal proportions within a single crystal structure. This cocktail of metals creates a uniquely stable and versatile atomic arrangement, often with properties that none of the individual metals could achieve alone.

This comprehensive review examines how high-entropy design principles can be applied to sodium-based energy storage. By combining multiple metals, researchers can stabilise crystal structures that resist degradation during repeated charge-discharge cycles, improve the movement of sodium ions, and ultimately build better, longer-lasting sodium batteries and supercapacitors. The paper surveys the field's progress and lays out guiding principles for designing next-generation sodium energy storage materials.

Reference

Siddanth, S. G., and Tiju Thomas. "High-Entropy Design Principles for Sodium-Based Electrochemical Energy Storage Systems." Coordination Chemistry Reviews 556 (2026): 217667. https://doi.org/10.1016/j.ccr.2026.217667 

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Lithium manganese oxide (LiMn₂O₄) is a promising cathode material for lithium-ion batteries because manganese is cheap, abundant, and less toxic than cobalt or nickel, which dominate today's commercial batteries. However, LiMn₂O₄ has a frustrating weakness: it tends to degrade over repeated charging and discharging, losing capacity and shortening battery life.

This paper digs deep into why that degradation happens. The researchers investigated three intertwined pathways: structural changes (how the crystal lattice distorts during cycling), electronic behaviour (how electrons move through the material), and interfacial phenomena (what happens at the boundary where the cathode meets the liquid electrolyte). Each pathway contributes to the instability, and they often reinforce each other in a vicious cycle.

By mapping out these degradation mechanisms in detail, the work provides a clearer target for engineers trying to stabilise LiMn₂O₄. If we can interrupt even one of these pathways, through coatings, doping, or electrolyte engineering, we could unlock a cheaper, greener battery chemistry for mass adoption.

Reference

Selvaraj, Siddanth, Gopinath, Snehith Adabala, Tarun Mateti, and Tiju Thomas. "Structural, Electronic, and Interfacial Pathways Governing the Stability of LiMn₂O₄ Spinel Cathodes." Batteries & Supercaps 9 (2026): e202500742. https://doi.org/10.1002/batt.202500742.

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Oxynitrides are materials that contain both oxygen and nitrogen in their crystal structure. They have attracted enormous interest for energy applications (solar cells, supercapacitors, water splitting catalysts) because substituting some oxygen atoms with nitrogen can dramatically change a material's electronic properties, often in beneficial ways, such as narrowing the band gap to absorb more sunlight.

A popular way to make oxynitrides is by heating metal oxide precursors with urea, a cheap nitrogen source. But here is the catch: the chemistry of this reaction is more ambiguous than many researchers assume. Urea decomposes in multiple stages, releasing ammonia, carbon dioxide, and various intermediate compounds, and the exact conditions determine whether nitrogen truly enters the crystal lattice or merely coats the surface.

This perspective paper calls attention to these ambiguities. It highlights common pitfalls in interpreting experimental data (for instance, mistaking surface nitrogen for structural incorporation) and proposes more rigorous characterisation protocols. The goal is to help the community produce oxynitrides with better-understood and more reproducible compositions, which is essential if these materials are ever to move from the lab to commercial devices.

Reference

Joseph, Anit, Chithra Ashok, Shotaro Tada, and Tiju Thomas. "Ambiguities in Oxynitride Chemistry: A Perspective on Urea-Mediated Synthesis." Inorganic Chemistry Communications 186, Part 2 (2026): 116267. https://doi.org/10.1016/j.inoche.2026.116267.

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Producing hydrogen by splitting water using electricity (electrolysis) is central to the clean energy transition, because hydrogen can store renewable energy and power fuel cells. Nickel is a popular electrode material for this process because it is far cheaper than platinum. But researchers have noticed something puzzling: trace amounts of iron, often present as an unintentional impurity in the chemicals used, can dramatically change how well nickel electrodes perform.

This study systematically investigates that effect. By carefully controlling the concentration of iron impurities, the team discovered that the relationship is not straightforward: a little iron can actually boost performance by modifying the electrode surface in helpful ways, but too much iron does the opposite, clogging active sites and slowing down the hydrogen-producing reaction.

Understanding this concentration-dependent behaviour is critical because "pure" laboratory chemicals are never perfectly pure, and iron contamination is nearly ubiquitous. This work helps the community understand apparently contradictory results in the literature and provides practical guidance for optimising nickel-based electrodes for large-scale green hydrogen production.

Reference

Khavala, Vedasri Bai, Christian Schneemann, Valentina Kallina, Carsten Dosche, Tiju Thomas, B. S. Murty, and Mehtap Oezaslan. "Concentration-Dependent Effects of Iron Impurities on Nickel Electrodes for Hydrogen Evolution Reaction in Alkaline Media." International Journal of Hydrogen Energy 206 (2026): 153320. https://doi.org/10.1016/j.ijhydene.2025.153320.

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Here is a fact that might surprise you: human urine is rich in nitrogen, phosphorus, and potassium, the exact nutrients plants need to grow. Every day, we flush these valuable resources into sewage systems, where they become pollutants rather than fertilisers. Closed-loop sanitation systems aim to change that by capturing urine at the source (the toilet) and recovering its nutrients for agricultural use.

This comprehensive review examines the entire chain: from the social and engineering challenges of separating urine at the household level, to the technologies available for converting collected urine into safe, effective fertiliser, to the broader nutrient-recovery ecosystem. It covers membrane filtration, struvite precipitation, electrochemical methods, and biological processing, evaluating each on cost, scalability, and nutrient recovery efficiency.

The paper is a call to rethink sanitation not as a disposal problem but as a resource recovery opportunity, one that could simultaneously reduce water pollution, cut dependence on synthetic fertilisers (which are energy-intensive to produce), and improve soil health, particularly in developing countries where both sanitation infrastructure and fertiliser access are limited.

Reference

Govindarajan, Dhivakar, M. Devasena, Indumathi M. Nambi, Tiju Thomas, Harold Leverenz, and Kahui Lim. "Closed Loop Sanitation Systems (CLSS): A Comprehensive Review on Challenges in Source Separation, Urine-Based Fertilization and Nutrient Recovery Technologies." Waste and Biomass Valorization (2026). https://doi.org/10.1007/s12649-025-03462-2.

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This study creates a single material that can do two important energy jobs at once. The material is a "high-entropy spinel oxide," meaning it combines five different metals (aluminium, chromium, iron, manganese, and nickel) in a spinel crystal structure, a specific atomic arrangement where metals sit in both octahedral and tetrahedral sites.

Why five metals? When you force this many different elements into one lattice, the resulting high configurational entropy (a thermodynamic measure of disorder) actually stabilises the structure, making it surprisingly robust. The team synthesised this material as tiny nanocrystals, maximising the surface area available for electrochemical reactions.

The bifunctional capability is the headline: the same electrode material works both as a supercapacitor (storing and releasing electrical energy very rapidly, like a rechargeable energy buffer) and as a catalyst for the oxygen evolution reaction (the bottleneck half-reaction in water splitting for hydrogen production). Having one material serve both functions simplifies device design and reduces cost. This is a demonstration of how high-entropy materials engineering can yield multifunctional energy materials.

Reference

Sreenivasulu, N., U. Naveen Kumar, Tiju Thomas, and S. S. Bhattacharya. "Nanocrystalline High Entropy M₃O₄ (M = Al, Cr, Fe, Mn, Ni) Spinel Oxide as a Bifunctional Electrode for Supercapacitor and Oxygen Evolution Reaction." Journal of Power Sources 666 (2026): 239056. https://doi.org/10.1016/j.jpowsour.2025.239056.

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Supercapacitors, devices that charge and discharge much faster than batteries, need electrode materials with enormous surface areas. Carbon derived from biomass (agricultural waste, fruit peels, wood, coconut shells) is an attractive option because it is cheap, renewable, and can be processed into highly porous structures. But the preparation process has many tuneable variables: temperature, activation agent, heating time, biomass source, and so on, and figuring out which combination yields the best performance has traditionally been a slow, trial-and-error process.

This study uses machine learning (ML) to cut through that complexity. The team trained models on published data from hundreds of biomass-carbon experiments, letting algorithms identify which preparation parameters matter most for supercapacitor performance. But they went a step further with "explainable AI" (XAI), techniques that open the black box of ML models to reveal why they make certain predictions.

The XAI analysis uncovered physically meaningful insights: for instance, that specific surface area and pore size distribution are the dominant predictors, and that certain activation temperatures interact with particular biomass types in non-obvious ways. This is not just a data exercise; it translates into actionable guidelines for experimentalists, telling them where to focus their effort for maximum payoff.

Reference

Ghosh, Sourav, Ashwath Sibi, and Tiju Thomas. "Machine Learning and Explainable Artificial Intelligence Reveal Physical Insights into Biomass-Derived Carbon for High-Performance Supercapacitors." Journal of Power Sources 665 (2026): 239040. https://doi.org/10.1016/j.jpowsour.2025.239040.

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