The study, published in Advances in Industrial and Engineering Chemistry, describes electrodes made by ion-sputtering platinum onto polished copper foil for either 10 or 60 seconds, followed by laser treatment with a 450 nm diode laser or a 1064 nm fiber laser. The researchers systematically varied laser power, scan speed, and treatment pattern, then ran one-hour electrolysis experiments at fixed potentials in three different electrolytes: potassium bicarbonate, potassium carbonate, and potassium phosphate buffer. Products were quantified with gas chromatography for gases and proton NMR spectroscopy for liquids, capturing everything from hydrogen and methane to propanol and even glycolaldehyde.

The headline result is the transformation of the platinum-coated copper electrode. Without laser treatment, the 60-second Pt/Cu electrode was essentially a hydrogen factory, producing hydrogen at roughly 69 percent Faradaic efficiency and formate as its only liquid product. After treatment with the 1064 nm laser at full power, hydrogen evolution collapsed to about 26 percent, and the electrode suddenly began producing ethanol at 10.7 percent, propanol at 6.8 percent, methanol, and acetate. Ethylene production jumped roughly twelvefold, from 0.93 percent to 12.27 percent Faradaic efficiency. In other words, a laser scan converted a nearly inert, hydrogen-spewing surface into a genuine carbon-carbon coupling catalyst.

Wavelength mattered enormously. The 450 nm laser, which transfers energy to the copper substrate less efficiently, produced no visible nanostructures under electron microscopy and only modest changes in product distribution. The 1064 nm laser, by contrast, blanketed the surface with dense spherical nanoparticles and triggered the biggest selectivity shifts. On bare copper, 1064 nm treatment boosted ethylene to 12.1 percent and pushed total long-chain hydrocarbon yields up about tenfold. The authors attribute these differences to how effectively each wavelength melts, ablates, and oxidizes the thin metal films, creating distinct populations of active sites.

Perhaps the most surprising discovery came from a fine-grained sweep of 1064 nm laser power between 20 and 30 percent. In that narrow window, the product palette exploded. At 25 percent power, ethanol peaked at nearly 19 percent and acetate at 3.5 percent. From 26 percent onward, propanol, isopropanol, methanol, and acetaldehyde all appeared, with isopropanol and acetaldehyde detected only within the 26 to 30 percent range. This razor-thin sensitivity suggests that the density and spacing of laser-generated nanoparticles, rather than bulk composition alone, control which carbon-carbon coupling pathways are accessible. It also hints at a practical dial: turn the laser power up or down and the electrode’s product portfolio changes accordingly.

The researchers frame their findings through the lens of electrochemical Fischer-Tropsch chemistry, the same chain-growth logic that governs industrial synthesis of fuels from syngas. By fitting Anderson-Schulz-Flory plots to their hydrocarbon distributions, they found that although alkanes have a slightly higher intrinsic chain-growth probability, hydrogenation is kinetically hindered at strongly reducing potentials. The practical consequence is that laser-treated surfaces favor unsaturated products: the alkene-to-alkane ratios for both C2 and C3 products rose consistently after laser treatment, with C3 ratios climbing to around ten at 1064 nm. Higher laser power appears to suppress post-coupling hydrogenation, letting ethylene and propene desorb before they can be saturated into ethane and propane.

Applied potential added another layer of control. On laser-patterned electrodes, formate was the sole liquid product at mild potentials of minus 1.4 to minus 1.6 volts, but from minus 1.8 volts onward the full liquid spectrum emerged, including propanol peaking at 7.4 percent, ethanol holding steady at 7 to 9 percent, and, uniquely at minus 2.2 volts, acetaldehyde and glycolaldehyde. Ethylene climbed roughly twelvefold across the potential window, while methane rose steadily to about 6 percent at the most negative potentials. Electrolyte concentration worked in the opposite direction: dilute 0.05 M bicarbonate maximized long-chain hydrocarbons and product diversity, while concentrated 0.5 M electrolyte drove hydrogen evolution to a crushing 95 percent on the platinum-coated electrode, leaving only formate behind.

Electrochemical diagnostics revealed why laser power demands such careful tuning. Double-layer capacitance measurements showed that moderate 50 percent laser power maximized the electrochemical surface area at roughly 16 square centimeters, while full-power treatment flattened the surface and shrank the active area to 3.24 square centimeters. Impedance spectroscopy told a two-sided story: excessive laser exposure built a thick, resistive oxide layer that impeded electron transport, yet simultaneously created a porous morphology that improved mass transport of reactants. Linear sweep voltammetry confirmed that the fully treated electrode delivered the highest cathodic currents near minus 2 volts, likely thanks to that oxide-rich surface, even as its conductivity suffered.

Depth-profiled X-ray photoelectron spectroscopy peeled back the chemical story layer by layer. On untreated Pt/Cu electrodes, the surface carried a mix of metallic platinum, oxidized platinum, and copper oxides, all of which were partially reduced during electrolysis. On laser-treated electrodes, the picture changed radically: the platinum signal nearly vanished at the surface, indicating the laser had stripped or thinned the overlayer, while copper was locked in a clean metallic state that resisted oxidation throughout the reaction. Ion scattering spectroscopy, reflected electron energy loss spectroscopy, and ultraviolet photoelectron spectroscopy corroborated this picture, and the reappearance of faint platinum signals after electrolysis hinted at subtle platinum rearrangement under operating conditions. Crucially, depth profiling confirmed that platinum survived on the electrode, proving the activity truly arises from the engineered Pt/Cu composite rather than bare copper alone.

What makes this work resonate beyond one laboratory is its manufacturing logic. Laser ablation requires no chemical baths, no exotic precursors, and no vacuum deposition beyond a simple sputtering step, and it scales naturally to large electrode areas with excellent reproducibility. As the authors conclude, the technique offers a scalable, non-chemical route to bimetallic interfaces whose electronic structure, oxidation state, and nanoscale texture can all be dialed in with a programmable beam. For a field racing to convert captured CO2 into ethylene, ethanol, and higher alcohols at industrially meaningful rates, the idea that a laser engraver could serve as a catalyst design tool is an invitation to rethink how electrocatalysts are made.

Subject of Research: Laser-ablation interface engineering of Pt-deposited Cu electrodes for electrochemical CO2 reduction to multi-carbon products

Article Title: Interface engineering of Pt-deposited Cu electrodes via laser ablation for enhanced electrochemical CO2 reduction to multi-carbon products

Article References: Interface engineering of Pt-deposited Cu electrodes via laser ablation for enhanced electrochemical CO2 reduction to multi-carbon products. (n.d.). https://doi.org/10.1007/s44405-025-00019-8

Image Credits: AI Generated

DOI: 10.1007/s44405-025-00019-8

Keywords: electrochemical CO2 reduction, copper catalysts, platinum, laser ablation, ethylene, ethanol, Faradaic efficiency, C-C coupling, Fischer-Tropsch, bimetallic electrodes, XPS, electrocatalysis

Electrochemical generation of sodium hypochlorite is conceptually straightforward. When a sodium chloride brine is electrolyzed, chloride ions are oxidized at the anode to produce chlorine gas, which hydrolyzes in water to form hypochlorous acid and, in the bulk solution, hypochlorite. Meanwhile, water is reduced at the cathode, generating hydrogen gas and hydroxide ions that combine with the hypochlorite to yield sodium hypochlorite. The overall reaction can be written in simplified form as NaCl plus H2O yielding NaOCl plus H2. In practice, however, the process is riddled with competing pathways. Oxygen evolution at the anode steals electrons that should go to chlorine production, hypochlorite decomposes chemically, chlorine can volatilize out of solution, and elevated voltages drive secondary oxidation to chlorate. The efficiency of the whole enterprise therefore hinges on the electrode material and the geometry of the cell.

The industrial gold standard is the dimensionally stable anode, or DSA: a titanium substrate coated with mixed metal oxides such as ruthenium and iridium dioxide. These anodes achieve current efficiencies above 90 percent and last for years, but they are expensive and often inaccessible in the decentralized, resource-limited settings where on-site generation would be most valuable. Recent research has pushed the frontier further with titanium suboxide architectures, cost-efficient Ti–V–Sn–Sb electrodes, and even high-entropy alloy nanowires capable of selective chlorine evolution from seawater. What has been missing, the Ghanaian team argues, is something more mundane but arguably more practical: a fair, side-by-side comparison of the cheap, widely available materials that a workshop in a rural clinic or a small water utility could actually obtain.

That gap matters because most published electrochlorination studies examine a single electrode material under its own idiosyncratic conditions: different reactor geometries, electrolyte concentrations, hydrodynamics, and voltages. Differences in reported performance may therefore reflect the operating conditions rather than the intrinsic properties of the material. To eliminate this confounding, Samuel Kofi Tulashie and colleagues evaluated five accessible non-DSA materials—aluminum, copper, graphite, stainless steel, and platinum—under strictly identical conditions. Each material served as both anode and cathode in a membrane-less, stirred 250-milliliter batch cell containing 20 grams per liter of sodium chloride at near-neutral pH of 7.02. The team systematically varied the electrode spacing from 4 to 10 centimeters and the applied voltage from 6 to 12 volts, running each electrolysis for 40 minutes and quantifying accumulated free chlorine by iodometric titration at 10-minute intervals.

The first finding concerns geometry. Reducing the electrode spacing from 10 to 8 centimeters increased free chlorine formation for every material tested, an effect the authors attribute to reduced ohmic resistance in the solution, which lowers the required cell potential and increases the effective current delivered at a fixed applied voltage. But the trend did not continue monotonically. Shrinking the gap further to 6 and then 4 centimeters actually reduced free chlorine output, even though output at those spacings still exceeded the 10-centimeter case. The maximum at 8 centimeters suggests a sweet spot where electrical, mass-transport, and hydrodynamic effects are favorably balanced. Below the optimum, the researchers propose, concentration polarization and non-uniform current distributions may intensify competing side reactions, while the chlorine and oxygen bubbles generated at the electrodes can crowd together, partially blocking active sites and disrupting electrolyte flow. The authors are careful to note that bubble dynamics were not directly measured, so these explanations remain plausible interpretations rather than demonstrated mechanisms.

When it came to the materials themselves, graphite emerged as the clear winner, accumulating approximately 189 milligrams per liter of free chlorine after 40 minutes—the highest of any electrode. Stainless steel followed at roughly 156 milligrams per liter, copper at about 89, aluminum at about 75, and platinum, remarkably, brought up the rear at around 71 milligrams per liter. The graphite result is consistent with a growing literature on carbon-based electrochlorination and makes physical sense: graphite surfaces are relatively inert toward active chlorine, limiting catalytic decomposition and allowing hypochlorite to accumulate. Stainless steel performed well because the mixed iron-chromium oxide layers that form during anodic polarization remain sufficiently stable under these conditions to sustain chlorine production before extensive passivation sets in.

The underperformance of aluminum and copper tells a cautionary tale about corrosion. Under anodic polarization in chloride-rich electrolyte, copper readily forms Cu+ and Cu2+ species, while aluminum undergoes localized pitting corrosion once its passive oxide layer breaks down. Dissolved metal ions are known catalysts for active chlorine decomposition through redox cycling, so these electrodes effectively destroy the very product they generate. The modest, near-linear rise in free chlorine over time for these materials suggests that generation and decomposition proceeded simultaneously throughout the electrolysis. Platinum’s poor showing is more subtle and, in its way, more instructive. The noble metal sustained the highest current densities across the entire voltage range, yet converted only a small fraction of that charge into measurable free chlorine. The likely culprit is the competing oxygen evolution reaction, which on platinum diverts electrons away from chloride oxidation. The lesson is blunt: pushing more current through a cell does not guarantee more disinfectant.

To quantify this, the team calculated absolute Faradaic efficiencies for free chlorine formation, relating the moles of product to the total charge passed. For all electrodes, efficiency decreased as applied voltage rose, indicating that progressively more of the electrical charge was lost to parasitic pathways—oxygen evolution, chlorine volatilization, hypochlorite decomposition, corrosion reactions, and chlorate formation. Graphite and stainless steel posted the highest efficiencies across the voltage range, confirming their superior charge utilization, while platinum, aluminum, and copper lagged substantially. For the corroding metals, anodic dissolution itself consumed charge that should have gone to chlorine production. The authors emphasize that these figures represent system-level charge utilization rather than intrinsic chlorine-evolution selectivity, since iodometric titration measures total free chlorine without distinguishing species or accounting for oxychlorine by-products.

The study is candid about its limitations, which is part of what makes it useful. The experiments captured only short-duration performance in an undivided batch cell; long-term electrode stability, chlorate and perchlorate formation, specific energy consumption, and lifecycle cost were all beyond scope. Electrode geometries differed—flat plates for the metals, cylindrical rods for graphite and platinum—and the constant-voltage operation without a reference electrode means the results should be read as comparative system benchmarks, not intrinsic electrocatalytic rankings. Minor chlorine loss to the headspace of the open, stirred reactor may also have introduced a small negative bias. The authors call for future work with geometrically identical electrodes under constant-current conditions, extended operation, cyclic voltammetry, impedance spectroscopy, and techno-economic assessment.

Even with those caveats, the practical message is striking. Two of the cheapest, most universally available materials on the planet—graphite and stainless steel—delivered the best combination of disinfectant output and charge efficiency, outperforming platinum under these conditions. For communities and small utilities considering decentralized electrochlorination, where titanium-based DSAs may be unavailable or economically prohibitive, that is genuinely good news. It suggests that the barrier to safe, locally produced disinfectant is not exotic materials science but careful engineering of the cells we can already build, with the right electrode gap, the right voltage, and the right pair of humble electrodes immersed in salt water.

Subject of Research: Benchmarking of low-cost electrode materials for electrochemical sodium hypochlorite generation

Article Title: Benchmarking accessible electrode materials for electrochemical sodium hypochlorite production

Article References: Tulashie, S. K., Atiiga, A.-W. I., Mensah, S., Teye, S. O., Arkorful, R., Iddrisu, M., Olorunyomi, M. O., Nsiah, F., Zugle, R., Alimoh, G., Adukpo, G., & Koomson, S. (2026). Benchmarking accessible electrode materials for electrochemical sodium hypochlorite production. Discover Electrochemistry, 3(1), Article 64. https://doi.org/10.1007/s44373-026-00152-z

Image Credits: AI Generated

DOI: 10.1007/s44373-026-00152-z

Keywords: sodium hypochlorite, electrochlorination, graphite electrode, stainless steel, platinum, Faradaic efficiency, chlorine evolution, on-site disinfection, electrode spacing, water treatment, decentralized systems, electrochemistry

The achievement matters because photocatalysis, the use of light-activated semiconductors to drive chemical reactions that shred organic contaminants, has long been hampered by an uncomfortable trade-off. Titanium dioxide, the workhorse of the field, is cheap and stable but absorbs only ultraviolet light, a sliver of the solar spectrum. Tantalum pentoxide suffers from the same limitation: it is a wide-bandgap oxide with excellent charge-transport properties and chemical robustness, yet it largely ignores the visible photons that make up most of the sunlight reaching the Earth’s surface. Closing that gap is one of the central challenges of environmental photocatalysis, and the new study offers a layered answer.

The researchers built their catalyst films in two stages. First, they used a hydrothermal process to produce the components and then employed doctor blading, a technique borrowed from industrial coating, to cast the films onto substrates. Platinum and ruthenium were introduced afterward by wet impregnation, allowing the noble metals to anchor onto the composite. By systematically varying the proportion of indium sulfide from 25 to 75 weight percent, the team could tune the composition and identify the recipe that delivered the best combination of light harvesting and charge handling.

Characterization told a compelling story. X-ray diffraction, ultraviolet-visible diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy with energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy were all brought to bear on the films. The optimized composite, containing 75 weight percent indium sulfide, exhibited a narrowed bandgap of roughly 2.14 electron volts, comfortably within the visible-light regime, along with increased absorption across the visible spectrum. Electron microscopy revealed uniformly distributed plate-like indium sulfide particles resting on the tantalum oxide framework, and the composite also possessed a larger surface area than its counterparts, providing more active sites for reactions.

The most intriguing findings came from the spectroscopy. X-ray photoelectron spectra showed binding energy shifts that pointed to strong electronic interactions between the platinum and ruthenium species and the tantalum pentoxide support. The analysis also revealed the formation of partially oxidized metal species and oxygen vacancies in the oxide lattice. These defects are far from flaws in this context; they act as effective charge-trapping sites, catching the electrons and holes that light excites inside the semiconductor before they can recombine and waste the absorbed energy as heat. In photocatalysis, keeping those charge carriers alive long enough to do chemistry is half the battle.

When the films were immersed in Rhodamine B solution and illuminated with visible light, the performance followed directly from that design. The optimized indium sulfide/platinum,ruthenium-modified tantalum pentoxide composite achieved up to 92.0 percent dye removal after 120 minutes, and the researchers report high recyclability, an essential quality for any catalyst hoped to leave the laboratory. Scavenger experiments, in which specific chemicals are added to neutralize particular reactive species, revealed that superoxide radicals were the dominant actors in the degradation. That result is significant because it indicates that electrons leaving the catalyst are efficiently transferred to dissolved oxygen molecules, converting them into the aggressive radical species that attack and dismantle the dye.

According to the authors, the enhanced performance arises from the interplay of three mechanisms working in concert. The heterojunction formed between indium sulfide and the modified tantalum oxide creates an internal electrical field that drives photogenerated charges in opposite directions, suppressing recombination. The platinum and ruthenium dopants further improve charge separation by acting as electron sinks with favorable electronic structures. And the defect-mediated electronic interactions, including the oxygen vacancies and partially oxidized metal species identified by photoelectron spectroscopy, provide the trapping sites that shepherd charges toward the surface reactions that generate superoxide. It is, in effect, a division of labor in which every component handles a different bottleneck of the photocatalytic process.

The broader context makes the work timely. Rhodamine B and related dyes are persistent, colored, and often toxic constituents of textile wastewater, and conventional treatment plants struggle to remove them completely. Advanced oxidation processes, including photocatalysis, have emerged as promising complements because they can mineralize organic pollutants rather than merely transferring them to another phase. Reviews of the field have emphasized that heterojunction photocatalysts, in which two semiconductors with staggered band structures are combined, are among the most active research directions, and this study adds a refined example that also leverages noble-metal modification and defect engineering simultaneously.

The choice of tantalum pentoxide as the oxide partner is deliberate. The material has a distinguished record in catalysis, supporting platinum nanoparticles in electrocatalysts and serving as a precursor for visible-light absorbers such as barium tantalum oxynitride. Its conduction band position is favorable for reducing oxygen, and its stability resists photocorrosion. Pairing it with indium sulfide, a narrow-gap visible absorber, covers the weakness of each partner: the sulfide brings the light absorption, while the oxide and its metal dopants bring the charge management and stability. The resulting films, cast by a scalable coating method rather than a batch slurry, also point toward practical reactor designs in which the catalyst can be recovered and reused without filtration.

For a field that often advances one parameter at a time, the study demonstrates the payoff of co-designing composition, defect chemistry, and interface structure in a single system. The researchers suggest that the rational integration of indium sulfide with platinum,ruthenium-modified tantalum pentoxide represents a successful general approach for altering electronic structure and improving charge carrier dynamics in oxide-based photocatalysts. If the strategy transfers to other oxide-sulfide pairings and other pollutants, dye-laden industrial wastewater may one day meet its match in a thin film powered by nothing more than sunlight and cleverly arranged atoms. The work was supported by Thailand Science Research and Innovation, with synchrotron-based characterization provided through the SUT-NANOTEC-SLRI Joint Research Facility.

Subject of Research: Visible-light photocatalytic degradation of Rhodamine B using Pt,Ru-codoped In2S3/Ta2O5 heterostructured films

Article Title: Novel Pt,Ru-Codoped In₂S₃/Ta₂O₅ heterostructured films for the effective enhancement of visible-light photocatalytic degradation of Rhodamine B

Article References: Boonprakob, N., Huatong, N., Chanlek, N., Udonpan, K., Sae-Kung, C., & Zhao, C. (2026). Novel Pt,Ru-Codoped In₂S₃/Ta₂O₅ heterostructured films for the effective enhancement of visible-light photocatalytic degradation of Rhodamine B. Journal of Nanoparticle Research, 28(10), Article 246. https://doi.org/10.1007/s11051-026-06754-3

Image Credits: AI Generated

DOI: 10.1007/s11051-026-06754-3

Keywords: photocatalysis, In2S3, Ta2O5, heterostructure, platinum, ruthenium, Rhodamine B, dye degradation, oxygen vacancies, superoxide radicals, visible light, wastewater treatment