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Photocatalytic urea synthesis, utilizing N2 and CO2 as feedstock and sustainable solar energy, represents an environmentally friendly and promising alternative strategy. However, the conventional unidirectional gas phase co‐reduction techniques typically employes pose stringent demands for the design of key catalysts, reaction control, mass transfer, and other aspects, due to the disparity in physical properties, structure, and catalytic kinetics between N2 and CO2. Herein, Ru‐TiO2 is synthesized and employed as an effective catalyst for urea photo‐synthesis through a nitric acid‐mediated pathway combining nitrogen oxidation and subsequent kinetically advantageous nitrate and CO2 co‐reduction. A urea yield of 24.95 µmol h−1 g−1cat. is obtained through an innovative intermittent illumination method, AQE values of 4.7% and 6.3% at 380 and 420 nm, respectively. The remarkable photo‐activity is attributed to its unique oxygen vacancy‐anchored Ru nanostructure (Ru‐O4Ti1), which effectively activates inert N2 molecules to minish the disparity of orbital energy levels, facilitates the formation of crucial *NN(OH) intermediates, and serves as an "electronic pump" to avoid electronegativity effect for facilitating electron transfer from nitrogen to TiO2 support for urea photosynthesis. This study presents groundbreaking insights for nitrogen oxidation activation and provides brand‐new ideas for the direct resource utilization of nitrogen. [ABSTRACT FROM AUTHOR]

In the alkaline hydrogen evolution reaction (HER), the dissociation energy barrier of water, and the easy adsorption of OH on the catalyst are key factors that limit the catalytic activity. This work proposes a novel competing adsorption mechanism driven by dz2 electrons in the context of the alkaline HER. The high concentration of oxygen vacancies in Co doped SrRuO3 (V‐SRCO) results in the electron filling in the Ru 4dz2 orbital. Under alkaline conditions, the V‐SRCO exhibits a low overpotential of only 57.8 mV with a Tafel slope of 35 mV dec−1. Moreover, it exhibits sustained high activity for 60 h. The high HER activity of V‐SRCO can be attributed to the presence of a single electron in the dz2 orbital, which reduces the energy barrier for water dissociation. More importantly, the active electrons in the dz2 orbital can inject into the antibonding orbitals of OH, creating an unfavorable environment for OH adsorption on the catalyst. This work provides favorable conditions for efficient HER. [ABSTRACT FROM AUTHOR]

Multiply twinned icosahedrons possess a diversity of unique functionalities well‐suited to various applications, such as thermoelectric conversion. Regarding chalcogenide icosahedron, an unconventional yet promising thermoelectric candidate, disclosing its growth mechanism is rather challenging. This study uncovers the formation mechanism of thermoelectric Cu5+3xFe1‐xS4 (0 ≤ x ≤ 0.4) core‐shell nano‐icosahedrons, which is distinct from that of well‐known metal icosahedrons. Electron microscopy and molecular dynamics simulations reveal that the evolution into icosahedrons, stemming from the fivefold twin formation in the center of Cu5FeS4 particle aggregates, is accompanied by the gradual formation of Fe‐rich orthorhombic‐structured core and Cu‐rich cubic‐structured shell, which provides a peculiar stress relaxation mechanism. Further identified by density functional theory calculations, Fe atoms have the tendency to transform cubic Cu5FeS4 to its orthorhombic phase and in turn result in varied crystal structures and lattice parameters in the core and shell. Importantly, by adjusting the Cu/Fe ratio of the precursors, the stress‐releasing process and potential energy of icosahedrons are controllably tuned, generating Cu5+3xFe1‐xS4 icosahedrons with tunable diameters. Accordingly, a significantly enhanced thermoelectric zT of 0.90, the largest value for Cu5FeS4, is realized. This study will shed light on the design strategy for Cu‐based ternary chalcogenide icosahedrons with enhanced thermoelectric properties. [ABSTRACT FROM AUTHOR]

Photocatalytic nitrogen oxidation reactions has emerged as promising techniques for air‐based nitrate synthesis, bolstering sustainable nitrogen fixation in industrial chains centered around nitrates. However, significant disparities in orbital energy levels impose constraints on N2 conversion, highlighting the pivotal role of nitrogen activation, particularly in oxygen‐rich environments. Herein, a novel Ir‐WO3 catalyst with cation vacancy chains is fabricated and utilized as a highly efficient catalyst for thermal‐assisted nitrogen oxidation under an innovative discontinuous light illumination strategy. Remarkably, an unexpected NO3− yield of 381.21 µmol g−1 h−1 is achieved, marking a 10.4‐fold increase compared to regular continuous light illumination. This exceptional performance is attributed to the unique structure and discontinuous light illumination, which lowered the energy barrier of the rate‐determining step for forming *NN(OH) intermediates and enhanced the abundance of •OH. Furthermore, a novel •OH assisted nitrogen activation mechanism is proposed based on the identification of crucial N2O intermediate and operando experiments. This work offers novel insights into free radicals‐based photocatalytic conversion processes and also presents a potential nitrate synthesis pathway for nitrates‐centric industrial nitrogen fixation chains. [ABSTRACT FROM AUTHOR]

Photocatalytic urea synthesis, utilizing N2 and CO2 as feedstock and sustainable solar energy, represents an environmentally friendly and promising alternative strategy. However, the conventional unidirectional gas phase co‐reduction techniques typically employes pose stringent demands for the design of key catalysts, reaction control, mass transfer, and other aspects, due to the disparity in physical properties, structure, and catalytic kinetics between N2 and CO2. Herein, Ru‐TiO2 is synthesized and employed as an effective catalyst for urea photo‐synthesis through a nitric acid‐mediated pathway combining nitrogen oxidation and subsequent kinetically advantageous nitrate and CO2 co‐reduction. A urea yield of 24.95 µmol h−1 g−1cat. is obtained through an innovative intermittent illumination method, AQE values of 4.7% and 6.3% at 380 and 420 nm, respectively. The remarkable photo‐activity is attributed to its unique oxygen vacancy‐anchored Ru nanostructure (Ru‐O4Ti1), which effectively activates inert N2 molecules to minish the disparity of orbital energy levels, facilitates the formation of crucial *NN(OH) intermediates, and serves as an "electronic pump" to avoid electronegativity effect for facilitating electron transfer from nitrogen to TiO2 support for urea photosynthesis. This study presents groundbreaking insights for nitrogen oxidation activation and provides brand‐new ideas for the direct resource utilization of nitrogen. [ABSTRACT FROM AUTHOR]