Porous and Partially Dehydrogenated Fe2+-Containing Iron Oxyhydroxide Nanosheets for Efficient Electrochemical Nitrogen Reduction Reaction (ENRR)

The design and development of efficient catalysts for electrochemical nitrogen reduction reaction (ENRR) under ambient conditions are critical for the alternative ammonia (NH₃) synthesis from N₂ and H₂O, wherein iron-based electrocatalysts exhibit outstanding NH₃ formation rate and Faradaic efficiency (FE). Here, the synthesis of porous and positively charged iron oxyhydroxide nanosheets by using layered ferrous hydroxide as a starting precursor, which undergoes topochemical oxidation, partial dehydrogenated reaction, and final delamination, is reported. As the electrocatalyst of ENRR, the obtained nanosheets with a monolayer thickness and 10-nm mesopores display exceptional NH₃ yield rate (28.5 µg h⁻¹ mg_cat.⁻¹) and FE (13.2%) at a potential of −0.4 V versus RHE in a phosphate buffered saline (PBS) electrolyte. The values are much higher than those of the undelaminated bulk iron oxyhydroxide. The larger specific surface area and positive charge of the nanosheets are beneficial for providing more exposed reactive sites as well as retarding hydrogen evolution reaction. This study highlights the rational control on the electronic structure and morphology of porous iron oxyhydroxide nanosheets, expanding the scope of developing non-precious iron-based highly efficient ENRR electrocatalysts.     

Size-Defined Ru Nanoclusters Supported by TiO2 Nanotubes Enable Low-Concentration Nitrate Electroreduction to Ammonia with Suppressed Hydrogen Evolution

Anthropogenic nitrate pollution has an adverse impact on the environment and human health. As part of a sustainable nitrate management strategy, electrochemical denitrification is studied as an innovative strategy for nutrients recycling and recovering. It is, however, challenging to selectively electro-reduce nitrate with low-concentration for ammonia. Herein, the photo-deposition of size-defined Ru nanoclusters (NCs, average size: ≈1.66 nm) on TiO₂ nanotubes (NTs) is demonstrated, which show improved performance for nitrate-to-ammonia electroreduction with a maximum yield rate of ≈600 µg h⁻¹ cm⁻² and a faradic efficiency (FE) of > 90.0% across a broad range of potentials in comparison with electrodeposited Ru nanoparticles (NPs, average size: ≈23.78 nm) on TiO₂ NTs. Experimental and theoretical evidence further suggests the small-size Ru NCs with the intrinsically enhanced selectivity and activity because of the strong metal/substrate interaction and unsaturated coordination state. The findings highlight the size effect on Ru-based catalyst supported on metal oxides, a versatile catalytic model, which allows the regulation of hydrogen adsorption to favor ammonia production over the competing hydrogen evolution reaction.     

Salt‐Templated Construction of Ultrathin Cobalt Doped Iron Thiophosphite Nanosheets toward Electrochemical Ammonia Synthesis

Exploiting efficient electrocatalysts for electrochemical nitrogen reduction (NRR) is highly desired and deeply meaningful for realizing sustainable ammonia (NH₃) production under ambient conditions. The Fe protein contains one [Fe₄S₄] cluster and P cluster, which play an important role for transfer electron during the nitrogen fixing of nitrogenases. Based on the understanding of nitrogenase, the rising‐star 2D iron thiophosphite (FePS₃) nanomaterials may be highly active electrocatalysts toward NRR due to the ideal elemental composition. In this work, 2D FePS₃ nanosheets are successfully synthesized by a facile salt‐templated method. The FePS₃ nanosheets show better electrocatalytic NH₃ yield and faradaic efficiency (FE) than Fe₂S₃, which demonstrates that the P element indeed improves the NRR activity of Fe‐S. Theoretically, Co incorporation not only effectively prompts the conductivity of FePS₃, but also enhances the catalytic activities of Fe‐edge sites. Experimentally, Co‐doped FePS₃ (Co‐FePS₃) nanosheets exhibit a remarkable electrocatalytic performance toward NRR, such as high NH₃ yield rate of 90.6 µg h^?1 mg_cat^?1, high FE of 3.38%, and an excellent long‐term stability. Being the first theoretical and experimental report regarding FePS₃‐based electrocatalyst toward NRR, this work represents an important beginning to the family of metal thiophosphite as advanced electrocatalysts toward NRR.     

FeS2 quantum dots sensitized nanostructured TiO2 solar cell: photoelectrochemical and photoinduced absorption spectroscopy studies

Thin films of nanostructured TiO₂ have been modified with FeS₂ (pyrite) nano-particles by a low temperature chemical reaction of iron pentacarbonyl with sulfur in xylene. Quantum size effects are manifested by the observation of a blue shift in both absorption and photocurrent action spectra. PIA (Photoinduced absorption spectroscopy), where the excitation is provided by a square-wave modulated (on/off) monochromatic light emitting diode, is a multipurpose tool in the study of dye-sensitized solar cells. Here, PIA is used to study quantum-dot modified TiO₂ nanostructured electrodes. The PIA spectra obtained give evidence for long-lived photoinduced charge separation: electrons are injected into the metal oxide and holes are left behind in the FeS₂ quantum dot. Time-resolved PIA shows that recombination between electrons and holes occurs on a millisecond timescale. The Incident-Photon-to-Current Efficiency of about 23 % was obtained at 400 nm excitation. The performances of TiO₂ electrodes modified with FeS₂ are relatively low, which is explained by the presence of FeS₂ phases other than the photoactive pyrite phase, as follows from the XRD spectrum.     

Low‐Coordinate Step Atoms via Plasma‐Assisted Calcinations to Enhance Electrochemical Reduction of Nitrogen to Ammonia

The electrochemical N₂ reduction reaction (NRR) is emerging as a promising alternative to the industrial Haber–Bosch process for distributed and modular production of NH₃. Nevertheless, developing high‐efficiency catalysts to simultaneously realize both high activity and selectivity for the development of a sustainable NRR is very critical but extremely challenging. Here, a unique plasma‐assisted strategy is developed to synthesize iridium diphosphide nanocrystals with abundant surface step atoms anchored in P,N‐codoped porous carbon nanofilms (IrP₂@PNPC‐NF), where the edges of the IrP₂ nanocrystals are extremely irregular, and the ultrathin PNPC‐NF possesses a honeycomb‐like macroporous structure. These characteristics ensure that IrP₂@PNPC‐NF delivers superior NRR performance with an NH₃ yield rate of 94.0 µg h^?1 mg^?1_cat. and a faradaic efficiency (FE) of 17.8%. Density functional theory calculations reveal that the unique NRR performance originates from the low‐coordinate step atoms on the edges of IrP₂ nanocrystals, which can lower the reaction barrier to improve the NRR activity and simultaneously inhibit hydrogen evolution to achieve a high FE for NH₃ formation. More importantly, such a plasma‐assisted strategy is general and can be extended to the synthesis of other high‐melting‐point noble‐metal phosphides (OsP₂@PNPC‐NF, Re₃P₄@PNPC‐NF, etc.) with abundant step atoms at lower temperatures.     

Fabry–Pérot Oscillation and Room Temperature Lasing in Perovskite Cube‐Corner Pyramid Cavities

Recently, organometal halide perovskite‐based optoelectronics, particularly lasers, have attracted intensive attentions because of its outstanding spectral coherence, low threshold, and wideband tunability. In this work, high‐quality CH₃NH₃PbBr₃ single crystals with a unique shape of cube‐corner pyramids are synthesized on mica substrates using chemical vapor deposition method. These micropyramids naturally form cube‐corner cavities, which are eminent candidates for small‐sized resonators and retroreflectors. The as‐grown perovskites show strong emission ≈530 nm in the vertical direction at room temperature. A special Fabry–Pérot (F–P) mode is employed to interpret the light confinement in the cavity. Lasing from the perovskite pyramids is observed from 80 to 200 K, with threshold ranging from ≈92 µJ cm^?2 to 2.2 mJ cm^?2, yielding a characteristic temperature of T₀ = 35 K. By coating a thin layer of Ag film, the threshold is reduced from ≈92 to 26 µJ cm^?2, which is accompanied by room temperature lasing with a threshold of ≈75 µJ cm^?2. This work advocates the prospect of shape‐engineered perovskite crystals toward developing micro‐sized optoelectronic devices and potentially investigating light–matter coupling in quantum optics.     

Supercapacitor Electrodes Based on Hierarchical Mesoporous MnOx/Nitrided TiO2 Nanorod Arrays on Carbon Fiber Paper

Metal nitride nanoarrays are attractive to electrochemical energy storage and in this work, hierarchical mesoporous manganese oxide (MnO_x) nanoflakes and nitrided TiO₂ nanorod arrays (NTNA) are prepared on carbon fiber paper (CFP) by hydrothermal synthesis and electrodeposition. The MnO_x/NTNA/CFP electrode delivers outstanding electrochemical performance such as high areal capacitance of 327 mF cm⁻² at a current density of 0.25 mA cm⁻² and good cycling stability with 96% retention after 5000 cycles. Compared to the MnO_x/TiO₂/CFP and MnO_x/CFP electrodes, the MnO_x/NTNA/CFP electrode possesses better electrochemical properties such as higher areal capacitance, better electrochemical activity, and cycling life. The enhanced performance can be attributed to the nitrided TiO₂ nanorod arrays with higher conductivity offering low electrochemical impedance and fast ion/electron transfer. The MnO_x/NTNA/CFP electrode is a promising candidate in high‐performance supercapacitor applications.     

Highly Selective N2 Electroreduction to NH3 Using a Boron-Vacancy-Rich Diatomic Nb?B Catalyst

The ambient electrochemical N₂ reduction reaction (NRR) is a future approach for the artificial NH₃ synthesis to overcome the problems of high-energy consumption and environmental pollution by Haber–Bosch technology. However, the challenge of N₂ activation on a catalyst surface and the competitive hydrogen evolution reaction make the current NRR unsatisfied. Herein, this work demonstrates that NbB₂ nanoflakes (NFs) exhibit excellent selectivity and durability in NRR, which produces NH₃ with a production rate of 30.5 µg h⁻¹ mg_cat⁻¹ and a super-high Faraday efficiency (FE) of 40.2%. The high-selective NH₃ production is attributed to the large amount of active B vacancies on the surface of NbB₂ NFs. Density functional theory calculations suggest that the multiple atomic adsorption of N₂ on both unsaturated Nb and B atoms results in a significantly stretched N₂ molecule. The weakened NN triple bonds are easier to be broken for a biased NH₃ production. The diatomic catalysis is a future approach for NRR as it shows a special N₂ adsorption mode that can be well engineered.     

Amorphous Sn/Crystalline SnS2 Nanosheets via In Situ Electrochemical Reduction Methodology for Highly Efficient Ambient N2 Fixation

Electrochemical nitrogen reduction reaction (NRR) as a new strategy for synthesizing ammonia has attracted ever‐growing attention, due to its renewability, flexibility, and sustainability. However, the lack of efficient electrocatalysts has hampered the development of such reactions. Herein, a series of amorphous Sn/crystalline SnS₂ (Sn/SnS₂) nanosheets by an L‐cysteine‐based hydrothermal process, followed by in situ electrochemical reduction, are synthesized. The amount of reduced amorphous Sn can be adjusted by selecting electrolytes with different pH values. The optimized Sn/SnS₂ catalyst can achieve a high ammonia yield of 23.8 µg h^?1 mg^?1, outperforming most reported noble‐metal NRR electrocatalysts. According to the electrochemical tests, the conversion of SnS₂ to an amorphous Sn phase leads to the substantial increase of its catalytic activity, while the amorphous Sn is identified as the active phase. These results provide a guideline for a rational design of low‐cost and highly active Sn‐based catalysts thus paving a wider path for NRR.     

Graphene‐Encapsulated FeS2 in Carbon Fibers as High Reversible Anodes for Na+/K+ Batteries in a Wide Temperature Range

Developing low cost, long life, and high capacity rechargeable batteries is a critical factor towards developing next‐generation energy storage devices for practical applications. Therefore, a simple method to prepare graphene‐coated FeS₂ embedded in carbon nanofibers is employed; the double protection from graphene coating and carbon fibers ensures high reversibility of FeS₂ during sodiation/desodiation and improved conductivity, resulting in high rate capacity and long‐term life for Na⁺ (305.5 mAh g^?1 at 3 A g^?1 after 2450 cycles) and K⁺ (120 mAh g^?1 at 1 A g^?1 after 680 cycles) storage at room temperature. Benefitting from the enhanced conductivity and protection on graphene‐encapsulated FeS₂ nanoparticles, the composites exhibit excellent electrochemical performance under low temperature (0 and ?20 °C), and temperature tolerance with stable capacity as sodium‐ion half‐cells. The Na‐ion full‐cells based on the above composites and Na₃V₂(PO₄)₃ can afford reversible capacity of 95 mAh g^?1 at room temperature. Furthermore, the full‐cells deliver promising discharge capacity (50 mAh g^?1 at 0 °C, 43 mAh g^?1 at ?20 °C) and high energy density at low temperatures. Density functional theory calculations imply that graphene coating can effectively decrease the Na⁺ diffusion barrier between FeS₂ and graphene heterointerface and promote the reversibility of Na⁺ storage in FeS₂, resulting in advanced Na⁺ storage properties.     

Electrochemical Ammonia Synthesis via Nitrogen Reduction Reaction on a MoS2 Catalyst: Theoretical and Experimental Studies

The discovery of stable and noble‐metal‐free catalysts toward efficient electrochemical reduction of nitrogen (N₂) to ammonia (NH₃) is highly desired and significantly critical for the earth nitrogen cycle. Here, based on the theoretical predictions, MoS₂ is first utilized to catalyze the N₂ reduction reaction (NRR) under room temperature and atmospheric pressure. Electrochemical tests reveal that such catalyst achieves a high Faradaic efficiency (1.17%) and NH₃ yield (8.08 × 10^?11 mol s^?1 cm^?1) at ?0.5 V versus reversible hydrogen electrode in 0.1 m Na₂SO₄. Even in acidic conditions, where strong hydrogen evolution reaction occurs, MoS₂ is still active for the NRR. This work represents an important addition to the growing family of transition‐metal‐based catalysts with advanced performance in NRR.     

Dinitrogen Reduction Coupled with Methanol Oxidation for Low Overpotential Electrochemical NH3 Synthesis Over Cobalt Pyrophosphate as Bifunctional Catalyst

Electrochemical dinitrogen (N₂) reduction to ammonia (NH₃) coupled with methanol electro-oxidation is presented in the current work. Here, methanol oxidation reaction (MOR) is proposed as an alternative anode reaction to oxygen evolution reaction (OER) to accomplish electrons-induced reduction of N₂ to NH₃ at cathode and oxidation of methanol at anode in alkaline media thereby reducing the overall cell voltage for ammonia production. Cobalt pyrophosphate micro-flowers assembled by nanosheets are synthesized via a surfactant-assisted sonochemical approach. By virtue of structural and morphological advantages, the maximum Faradaic efficiency of 43.37% and NH₃ yield rate of 159.6 µg h⁻¹ mg_ca⁻¹ is achieved at a potential of −0.2 V versus RHE. The proposed catalyst is shown to also exhibit a very high activity (100 mA mg⁻¹ at 1.48 V), durability (2 h) and production of value-added formic acid at anode (2.78 µmol h⁻¹ mg_cat⁻¹ and F.E. of 59.2%). The overall NH₃ synthesis is achieved at a reduced cell voltage of 1.6 V (200 mV less than NRR-OER coupled NH₃ synthesis) when OER at anode is replaced with MOR and a high NH₃ yield rate of 95.2 µg h⁻¹ mg_cat⁻¹ and HCOOH formation rate of 2.53 µmol h⁻¹ mg⁻¹ are witnessed under full-cell conditions.     

Well‐Defined Single‐Atom Cobalt Catalyst for Electrocatalytic Flue Gas CO2 Reduction

Single‐atom Co catalyst Co‐Tpy‐C with well‐defined sites is synthesized by pyrolysis of a Co terpyridine (Tpy) organometallic complex. The Co‐Tpy‐C catalyst exhibits excellent activity for the electrochemical CO₂ reduction reaction in aqueous electrolyte, with CO faradaic efficiency (FE) of over 95% from ?0.7 to ?1.0 V (vs RHE). By comparison, catalysts without Co or Tpy ligand added do not show any high CO FE. When simulated flue gas with 15% of CO₂ is used as the source of CO₂, CO FE is kept at 90.1% at ?0.5 V versus RHE. During gas phase flow electrolysis using simulated flue gas, the CO partial current density is further increased to 86.4 mA cm^?2 and CO FE reached >90% at the cell voltage of 3.4 V. Experiments and density functional theory calculations indicate that uniform single‐atom Co–N₄ sites mainly contribute to the high activity for CO₂ reduction.     

Synergistically Coupling Black Phosphorus Quantum Dots with MnO2 Nanosheets for Efficient Electrochemical Nitrogen Reduction Under Ambient Conditions

The electrochemical nitrogen reduction reaction (NRR) is a promising strategy of nitrogen fixation into ammonia under ambient conditions. However, the development of electrochemical NRR is highly bottlenecked by the expensive noble metal catalysts. As a representative 2D nonmetallic material, black phosphorus (BP) has the valence electron structure similar to nitrogen, which can effectively adsorb the inactive nitrogen molecule and activate its triple bond. In addition, the relatively weak hydrogen adsorption can restrict the competitive and vigorous hydrogen evolution reaction. Herein, ultrafine BP quantum dots (QDs) are prepared via liquid‐phase exfoliation and then assembled on catalytically active MnO₂ nanosheets through van der Waals interactions. The obtained BP QDs/MnO₂ catalyst demonstrates admirable synergetic effects in electrochemical NRR. The monodisperse BP QDs providing major activity manifest excellent ammonia production steadily with high selectivity, which benefits from the robust confinement of the BP QDs on the wrinkled MnO₂ nanosheets with decent activity. A high ammonia yield rate of 25.3 µg h^?1 mg_cat.^?1 and faradic efficiency of 6.7% can be achieved at ?0.5 V (vs RHE) in 0.1 m Na₂SO₄ electrolyte, which are dramatically superior to either component. The isotopic labelling and other control tests further exclude the external contamination possibility and attest the genuine activity.     

Au Sub‐Nanoclusters on TiO2 toward Highly Efficient and Selective Electrocatalyst for N2 Conversion to NH3 at Ambient Conditions

As the N?N bond in N₂ is one of the strongest bonds in chemistry, the fixation of N₂ to ammonia is a kinetically complex and energetically challenging reaction and, up to now, its synthesis is still heavily relying on energy and capital intensive Haber–Bosch process (150–350 atm, 350–550 °C), wherein the input of H₂ and energy are largely derived from fossil fuels and thus result in large amount of CO₂ emission. In this paper, it is demonstrated that by using Au sub‐nanoclusters (≈0.5 nm ) embedded on TiO₂ (Au loading is 1.542 wt%), the electrocatalytic N₂ reduction reaction (NRR) is indeed possible at ambient condition. Unexpectedly, NRR with very high and stable production yield (NH₃: 21.4 µg h^?1 mg^?1_cat., Faradaic efficiency: 8.11%) and good selectivity is achieved at ?0.2 V versus RHE, which is much higher than that of the best results for N₂ fixation under ambient conditions, and even comparable to the yield and activation energy under high temperatures and/or pressures. As isolated precious metal active centers dispersed onto oxide supports provide a well‐defined system, the special structure of atomic Au cluster would promote other important reactions besides NRR for water splitting, fuel cells, and other electrochemical devices.     

Microenvironment Engineering to Promote Selective Ammonia Electrosynthesis from Nitrate over a PdCu Hollow Catalyst

The electrosynthesis of recyclable ammonia (NH₃) from nitrate under ambient conditions is of great importance but still full of challenges for practical application. Herein, an efficient catalyst design strategy is developed that can engineer the surface microenvironment of a PdCu hollow (PdCu-H) catalyst to confine the intermediates and thus promote selective NH₃ electrosynthesis from nitrate. The hollow nanoparticles are synthesized by in situ reduction and nucleation of PdCu nanocrystals along a self-assembled micelle of a well-designed surfactant. The PdCu-H catalyst shows a structure-dependent selectivity toward the NH₃ product during the nitrate reduction reaction (NO₃⁻RR) electrocatalysis, enabling a high NH₃ Faradaic efficiency of 87.3% and a remarkable NH₃ yield rate of 0.551 mmol h⁻¹ mg⁻¹ at -0.30 V (vs reversible hydrogen electrode). Moreover, this PdCu-H catalyst delivers high electrochemical performance in the rechargeable zinc-NO₃⁻ battery. These results provide a promising design strategy to tune catalytic selectivity for efficient electrosynthesis of renewable NH₃ and feedstocks.     

Ultrafast Growth of High‐Quality Monolayer WSe2 on Au

The ultrafast growth of high‐quality uniform monolayer WSe₂ is reported with a growth rate of ≈26 µm s^?1 by chemical vapor deposition on reusable Au substrate, which is ≈2–3 orders of magnitude faster than those of most 2D transition metal dichalcogenides grown on nonmetal substrates. Such ultrafast growth allows for the fabrication of millimeter‐size single‐crystal WSe₂ domains in ≈30 s and large‐area continuous films in ≈60 s. Importantly, the ultrafast grown WSe₂ shows excellent crystal quality and extraordinary electrical performance comparable to those of the mechanically exfoliated samples, with a high mobility up to ≈143 cm² V^?1 s^?1 and ON/OFF ratio up to 9 × 10⁶ at room temperature. Density functional theory calculations reveal that the ultrafast growth of WSe₂ is due to the small energy barriers and exothermic characteristic for the diffusion and attachment of W and Se on the edges of WSe₂ on Au substrate.     

Tuning Oxygen Vacancies in Ultrathin TiO2 Nanosheets to Boost Photocatalytic Nitrogen Fixation up to 700 nm

Dinitrogen reduction to ammonia using transition metal catalysts is central to both the chemical industry and the Earth's nitrogen cycle. In the Haber–Bosch process, a metallic iron catalyst and high temperatures (400 °C) and pressures (200 atm) are necessary to activate and cleave N?N bonds, motivating the search for alternative catalysts that can transform N₂ to NH₃ under far milder reaction conditions. Here, the successful hydrothermal synthesis of ultrathin TiO₂ nanosheets with an abundance of oxygen vacancies and intrinsic compressive strain, achieved through a facile copper‐doping strategy, is reported. These defect‐rich ultrathin anatase nanosheets exhibit remarkable and stable performance for photocatalytic reduction of N₂ to NH₃ in water, exhibiting photoactivity up to 700 nm. The oxygen vacancies and strain effect allow strong chemisorption and activation of molecular N₂ and water, resulting in unusually high rates of NH₃ evolution under visible‐light irradiation. Therefore, this study offers a promising and sustainable route for the fixation of atmospheric N₂ using solar energy.     

Hierarchically Nanoporous 3D Assembly Composed of Functionalized Onion‐Like Graphitic Carbon Nanospheres for Anode‐Minimized Li Metal Batteries

Despite the recent attention for Li metal anode (LMA) with high theoretical specific capacity of ≈ 3860 mA h g^?1, it suffers from not enough practical energy densities and safety concerns originating from the excessive metal load, which is essential to compensate for the loss of Li sources resulting from their poor coulombic efficiencies (CEs). Therefore, the development of high‐performance LMA is needed to realize anode‐minimized Li metal batteries (LMBs). In this study, high‐performance LMAs are produced by introducing a hierarchically nanoporous assembly (HNA) composed of functionalized onion‐like graphitic carbon building blocks, several nanometers in diameter, as a catalytic scaffold for Li‐metal storage. The HNA‐based electrodes lead to a high Li ion concentration in the nanoporous structure, showing a high CE of ≈ 99.1%, high rate capability of 12 mA cm^?2, and a stable cycling behavior of more than 750 cycles. In addition, anode‐minimized LMBs are achieved using a HNA that has limited Li content ( ≈ 0.13 mg cm^?2), corresponding to 6.5% of the cathode material (commercial NCM622 ( ≈ 2 mg cm^?2)). The LMBs demonstrate a feasible electrochemical performance with high energy and power densities of ≈ 510 Wh kg_electrode^?1 and ≈ 2760 W kg_electrode^?1, respectively, for more than 100 cycles.     

Pd-Doped Co3O4 Nanoarray for Efficient Eight-Electron Nitrate Electrocatalytic Reduction to Ammonia Synthesis

Ammonia (NH₃) is an indispensable feedstock for fertilizer production and one of the most ideal green hydrogen rich fuel. Electrochemical nitrate (NO₃⁻) reduction reaction (NO₃⁻RR) is being explored as a promising strategy for green to synthesize industrial-scale NH₃, which has nonetheless involved complex multi-reaction process. This work presents a Pd-doped Co₃O₄ nanoarray on titanium mesh (Pd-Co₃O₄/TM) electrode for highly efficient and selective electrocatalytic NO₃⁻RR to NH₃ at low onset potential. The well-designed Pd-Co₃O₄/TM delivers a large NH₃ yield of 745.6 µmol h⁻¹ cm⁻² and an extremely high Faradaic efficiency (FE) of 98.7% at −0.3 V with strong stability. These calculations further indicate that the doping Co₃O₄ with Pd improves the adsorption characteristic of Pd-Co₃O₄ and optimizes the free energies for intermediates, thereby facilitating the kinetics of the reaction. Furthermore, assembling this catalyst in a Zn-NO₃⁻ battery realizes a power density of 3.9 mW cm⁻² and an excellent FE of 98.8% for NH₃.