Perovskite and Carbon Nitride Team Up to Build a Better Battery Catalyst

Zinc-air batteries have long promised a cleaner, cheaper way to store electricity, but their commercial fortunes have been held hostage by a stubborn chemical bottleneck: the air electrode. On discharge, the oxygen reduction reaction (ORR) pulls oxygen out of the air and converts it into hydroxide ions; on recharge, the oxygen evolution reaction (OER) runs the process in reverse. Both reactions are notoriously sluggish, and the precious-metal catalysts that can speed them up, such as platinum and iridium oxides, are expensive and often excel at only one side of the chemistry. Now a research team based at the Taiyuan Institute of Technology in China, working with a colleague at Contemporary Amperex Technology, has reported a deceptively simple recipe for a catalyst that handles both reactions well, using abundant elements and a synthesis route that could plausibly be scaled.

The study, published in the journal Ionics, centers on a perovskite oxide of the lanthanum-strontium-manganese-cobalt family. Perovskites are a broad class of crystalline materials defined by their ABO3 lattice architecture, in which large cations occupy the A-sites and smaller transition metals sit at the B-sites surrounded by oxygen octahedra. Because the B-site composition can be tuned almost continuously, chemists can adjust the electronic structure of these oxides to favor particular catalytic reactions. The team started with La0.5Sr0.5Co0.53Mn0.47O3, a composition they abbreviate as LCO, in which strontium substitution on the lanthanum sites and a roughly even cobalt-manganese mix on the B-sites create the kind of mixed valence states that oxygen electrocatalysis thrives on.

What makes the new work interesting is not the perovskite itself but what the researchers did with it. Rather than simply mixing the oxide with a carbon support, they combined the perovskite precursor chemistry with graphitic carbon nitride, a layered polymer of carbon and nitrogen that has become a favorite raw material in catalysis because of its nitrogen-rich framework and thermal lability. Using a sol-gel synthesis coupled with a condensation reflux step, the team prepared a series of hybrid precursors containing varying proportions of the perovskite components and g-C3N4, ranging from 10 to 90 percent carbon nitride by precursor composition. These precursors were then calcined, and the heat treatment transformed them into something quite different from the starting materials: multiphase composites containing LaSrMnO3-based perovskite phases, cobalt oxide in the form of Co3O4 spinel, and nitrogen-doped carbon, all generated in situ from a single precursor blend.

This precursor-derived strategy is the conceptual heart of the paper. When the composite forms during calcination, the three phases are not merely juxtaposed; they emerge from an intimately mixed precursor, which tends to produce fine intergrowth, close interfacial contact, and a distribution of nitrogen atoms within the carbonaceous component. The resulting interfaces between the perovskite, the spinel cobalt oxide, and the nitrogen-doped carbon are precisely where the authors locate the catalytic magic. Systematic electrochemical testing across the whole compositional series showed that activity was not monotonic with carbon nitride content. Instead, the composite derived from the precursor containing 70 percent g-C3N4, denoted LCO/70%g-C3N4, stood out as the optimum, a clear sign that the balance among the three phases matters more than any single ingredient.

The numbers behind that optimum are striking. For the oxygen reduction reaction, the best composite delivered a half-wave potential of 0.78 volts versus the reversible hydrogen electrode, a standard benchmark of ORR activity. For the oxygen evolution reaction, it required an overpotential of just 387 millivolts to drive a current density of 10 milliamperes per square centimeter, another widely used yardstick. Compared with the pristine LCO perovskite, which managed only 0.69 volts for ORR and 478 millivolts of OER overpotential, the optimized composite improved both figures by roughly 90 millivolts. In electrocatalysis, where improvements of a few tens of millivolts are often celebrated, simultaneous gains of that magnitude on both sides of the oxygen chemistry are noteworthy, because the two reactions place different and sometimes conflicting demands on a catalyst’s electronic structure.

Why does the three-phase composite work so much better than the sum of its parts? The authors’ mechanistic analysis points to synergistic interactions among the LaSrMnO3-based phases, the Co3O4 spinel, and the nitrogen-doped carbon. Each component contributes something the others lack. Perovskite oxides offer robust, tunable transition-metal centers with the right orbital occupancy for oxygen intermediates, but they are relatively poor electrical conductors. Cobalt oxide spinel is an active OER catalyst in alkaline media and can provide additional active sites. Nitrogen-doped carbon supplies electrical conductivity, a high surface area scaffold, and its own catalytically useful nitrogen sites, while also anchoring the oxide particles and preventing them from sintering. At the interfaces between these phases, electronic charge transfer can modify the d-band of the transition metals, optimizing the binding energies of oxygen-containing intermediates and thereby lowering the kinetic barriers for both ORR and OER.

The choice of graphitic carbon nitride as the precursor is particularly clever. When g-C3N4 is heated in the presence of metal precursors, it does not simply burn off as an inert template. Its high nitrogen content means that carbon formed from its decomposition is inherently nitrogen-doped, without any post-synthetic ammonia treatment or other extra processing step. That in-situ doping is what gives the final composite its conductive, catalytically active carbon component for free, so to speak. The condensation reflux step used to prepare the precursors helps homogenize the metal species and the carbon nitride at the molecular level before calcination, which in turn promotes the fine dispersion of the resulting phases. The authors describe the overall route as facile, and in the context of catalyst synthesis that word carries real weight: routes that require only conventional sol-gel chemistry, reflux, and a furnace are far more amenable to scale-up than routes demanding exotic precursors, high-pressure equipment, or multistep surface functionalization.

The broader context makes the result timely. Zinc-air batteries are attractive because zinc is cheap, safe, and energy-dense, and because the cathode fuel, oxygen, comes from the atmosphere rather than from a tank. But every rechargeable zinc-air cell lives or dies by the bifunctional air electrode, and the field has been searching for alternatives to noble metals for years. Recent literature has explored iron and cobalt single-atom catalysts on nitrogen-doped carbon, dual-atom configurations, metal-organic framework derivatives, and doped perovskites of many compositions. The present work adds a distinct design principle to that toolbox: instead of doping the perovskite or decorating it with nanoparticles after synthesis, one can co-process the perovskite and a nitrogen-rich carbon precursor so that the entire multiphase architecture assembles itself during calcination. That principle should be portable to other perovskite chemistries and other nitrogen-containing precursors, which is arguably its most valuable implication.

There are, of course, the usual caveats that separate a laboratory benchmark from a commercial air electrode. The reported half-wave potentials and overpotentials were measured under the standardized conditions of aqueous electrochemical testing, and real zinc-air devices impose additional demands, including tolerance to zincate contamination, mechanical robustness under gas evolution, and stability over thousands of charge-discharge cycles. The study’s mechanistic analysis identifies synergy among the phases as the origin of the enhancement, but fully resolving how charge transfer at each interface reshapes the catalytic sites would require the kind of operando spectroscopy that such composites increasingly receive. The authors also note that data related to the article are available on reasonable request, and the work was supported by funding programs of Shanxi Province and the Taiyuan Institute of Technology, reflecting a sustained regional investment in energy materials research.

Even with those caveats, the study offers a satisfying demonstration of materials design by precursor engineering. By treating the perovskite and the carbon nitride not as separate catalyst and support but as co-reactants in a single thermal transformation, the researchers obtained a composite whose phases, interfaces, and nitrogen doping were all established in one step, and whose bifunctional performance clearly benefited from that intimacy. As the world scrambles to store renewable electricity at scale, progress on the humble air electrode may prove as consequential as progress on the batteries themselves, and this perovskite-carbon nitride recipe is a welcome addition to the growing catalog of earth-abundant catalysts designed to keep oxygen chemistry moving in both directions.

Subject of Research: Perovskite-derived multiphase electrocatalysts for bifunctional oxygen reduction and evolution reactions in zinc-air batteries

Article Title: Facile synthesis of LaSrMnO3-based multiphase composites derived from perovskite/g-C3N4 precursors for bifunctional ORR and OER

Article References: Yan, R., Wang, K., Zou, L., Liu, J., Xu, H., & Zhang, T. (2026). Facile synthesis of LaSrMnO3-based multiphase composites derived from perovskite/g-C3N4 precursors for bifunctional ORR and OER. Ionics. https://doi.org/10.1007/s11581-026-07532-w

Image Credits: AI Generated

DOI: 10.1007/s11581-026-07532-w

Keywords: perovskite, LaSrMnO3, graphitic carbon nitride, oxygen reduction reaction, oxygen evolution reaction, zinc-air battery, electrocatalysis, nitrogen-doped carbon, Co3O4, sol-gel synthesis, bifunctional catalyst, metal-air batteries