The oxygen evolution reaction (OER) is pivotal for diverse electrochemical energy conversion systems; however, it has so far been plagued by sluggish kinetics and excessive energy consumption. In this study, we proposed an innovative thermoelectric-electrocatalytic coupling strategy to enhance OER efficiency by constructing an Ohmic heterointerface through uniform integration of RuO2 with thermoelectric oxide (PrCoO3). Combined experimental and theoretical analyses revealed that the thermoelectric potential generated by PrCoO3 selectively activates the intrinsically inert (101) facet of RuO2 by lowering *OOH formation barrier, thereby substantially boosting the overall OER performance. Consequently, the RuO2/PrCoO3 heterointerface delivered exceptional OER performance under a mild temperature gradient (Delta T) of 175 degrees C, achieving dramatic reduction in overpotential at 10 mA cm-2 from 300 mV (Delta T = 0 degrees C) to 178 mV, 4 300% increase in current density, and negligible potential loss over 1,000 h. When the catalyst was assembled into an anion exchange membrane water electrolyzer, the cell driven by spontaneous heating reached a low voltage of 2.18 V at a current density of 2.0 A cm-2, with stable operation for 600 h. These insights into harnessing thermal gradient via integrated electrocatalytic system are crucial for the recovery of industrial waste heat and its conversion into high-value chemicals.
Photocatalytic H2O2 production via the two-electron oxygen reduction reaction (2e- ORR) offers a green alternative to the anthraquinone process, but single-component photocatalysts suffer from rapid charge recombination. Here, we construct an S-scheme heterojunction by growing ZnxCd1-xS (ZCS) quantum dots (QDs) in situ on hollow conjugated microporous polymers (CMPs) containing selenadiazole units (hPSe). The hollow CMPs scaffold provides high surface area, abundant pores for QDs embedding, efficient mass transfer, and enhanced light harvesting, while the selenadiazole units promote strong interfacial coupling. In pure water without any sacrificial agent, the optimal ZCS@hPSe-2 composite achieved an outstanding H2O2 production rate of 15.13 mmol g-1 h-1 with a synergy factor of 1.53 and an apparent quantum efficiency (AQE) of 8.82% at 400 nm, operating exclusively via the 2e- ORR. The dramatic performance is attributed to the S-scheme charge transfer mechanism, which preserves the strong redox potentials of both components and suppresses bulk charge recombination. This work demonstrates that rational integration of QDs with hollow CMPs provides a viable pathway toward efficient, additive-free photocatalytic H2O2 synthesis.
Photocatalytic urea synthesis directly from atmospheric CO2 and N2 offers a sustainable route to bypass the energy-intensive Bosch-Meiser process, yet simultaneously achieving CO2 capture and reduction, N2 activation, and C & horbar;N coupling within a single system remains challenging. Herein, we report a two-step tandem platform combining ionic-liquid-modified metal-organic framework (IL@PCN-250-Fe2Co) with a trinuclear copper-based covalent organic framework (HTP-Cu3-imi-COF) for urea photosynthesis from air. The IL@MOF captures atmospheric CO2 and photoreduces it to CO, while HTP-Cu3-imi-COF couples the generated CO with ambient N2 into urea. This synergistic tandem configuration delivers a urea production rate of 259.87 & micro;g & centerdot;gcat -1 & centerdot;h-1 under air, marking the first demonstration of photocatalytic urea synthesis from atmospheric CO2 and N2. In situ spectroscopic measurements and DFT calculations reveal that the imidazole-functionalized HTP segments act as hole-rich oxidation domains, promoting water oxidation to generate *OH species that oxidize locally enriched N2 to *NO intermediates. Simultaneously, the Cu3 clusters serve as electron-rich centers for CO adsorption and activation, forming *CO that couples with *NO via the critical *OCNO intermediate toward urea formation. This work not only showcases the first photocatalytic urea synthesis from air but also establishes a modular paradigm for cascade catalysts that integrate capture and conversion toward sustainable chemical transformations.
Multivalent cation-anion co-(de)intercalation offers a promising pathway to higher energy densities in multivalent ion batteries. However, its practical realization is challenged by lattice strain and the lack of effective dual charge-compensation strategies. Here, we report a layered vanadium oxide cathode with pre-intercalated melamine ligands (MeVO) that enables a spatially decoupled charge-compensation mechanism-organic ligands serve as redox centers for anions, while metal sites accommodate multivalent cation redox. This design alleviates electrostatic crowding, promotes ion mobility, and preserves structural integrity. Using Mg2 +-TFSI- as a representative system, MeVO delivers a record cycle life of over 36 000 cycles at a loading of approximately 3 mg cm- 2 and an areal capacity of 3.3 mAh cm- 2 at a higher loading of 16.4 mg cm- 2, surpassing leading Mg-ion cathodes. The hybrid structure also supports co-(de)intercalation of various multivalent cations and anions, demonstrating its potential as a versatile intercalation platform for high-performance energy storage.
We have synthesized layered superconducting LiNbO2 crystals through a bulk phase transformation from LiNbO3 single crystals via CaH2 reduction. As the Nb valence is reduced from 5+ to 3+, the material undergoes a structural transformation to the resulting product, LiNbO2, which is accompanied by metallic behavior and a superconducting transition, T c onset, as high as 14.4 K. Secondary ion mass spectroscopy (SIMS) and x-ray photoelectron spectroscopy (XPS) show that the resulting phase is hole-doped through de-lithiation during the reduction. Magnetization and AC susceptibility measurements from a tunnel diode resonator confirm the bulk nature of superconductivity with a superconducting volume fraction of approximate to 77% and an upper critical field approaching 26 T. Our study demonstrates extreme hydride reduction as an effective method to induce phase transformations with non-topochemical pathways and can be used to synthesize bulk materials with exotic properties.
