Gram-level NH3 Electrosynthesis via NOx reduction on a Cu Activated Co Electrode.

Ambient electrochemical ammonia (NH3 ) synthesis is one promising alternative to the energy-intensive Haber-Bosch route. However, the industrial requirement for the electrochemical NH3 production with amperes current densities or gram-level NH3 yield remains a grand challenge. Herein, we report the high-rate NH3 production via NO2 - reduction using the Cu activated Co electrode in a bipolar membrane (BPM) assemble electrolyser, wherein BPM maintains the ion balance and the liquid level of electrolyte. Benefited from the abundant Co sites and optimal structure, the target modified Co foam electrode delivers a current density of 2.64 A cm-2 with the Faradaic efficiency of 96.45 % and the high NH3 yield rate of 279.44 mg h-1 cm-2 in H-type cell using alkaline electrolyte. Combined with in situ experiments and theoretical calculations, we found that Cu optimizes the adsorption behavior of NO2 - and facilitates the hydrogenation steps on Co sites toward a rapid NO2 - reduction process. Importantly, this activated Co electrode affords a large NH3 production up to 4.11 g h-1 in a homemade reactor, highlighting its large-scale practical feasibility.

Fully exposed nickel clusters with electron-rich centers for high-performance electrocatalytic CO2 reduction to CO.

Single-atom catalysts (SACs) have attracted increasing concerns in electrocatalysis because of their maximal metal atom utilization, distinctive electronic properties, and catalytic performance. However, the isolated single sites are disadvantageous for reactions that require simultaneously activating different reactants/intermediates. Fully exposed metal cluster catalyst (FECC), inheriting the merits of SACs and metallic nanoparticles, can synergistically adsorb and activate reactants/intermediates on their multi-atomic sites, demonstrating great promise in electrocatalytic reactions. Here a facile method to regulate the atomic dispersion of Ni species from cluster to single-atom scale for efficient CO2 reduction was developed. The obtained Ni FECC exhibits high Faradaic efficiency of CO up to 99%, high CO partial current density of 347.2 mA cm-2, and robust durability under 20 h electrolysis. Theoretical calculations illuminate that the ensemble of multiple Ni atoms regulated by sulfur atoms accelerates the reaction kinetics and thus improves CO production.

Boosting Electrochemical Carbon Dioxide Reduction on Atomically Dispersed Nickel Catalyst.

Single-atom catalysts (SACs) with metal-nitrogen (M-N) sites are one of the most promising electrocatalysts for electrochemical carbon dioxide reduction (ECO2R). However, challenges in simultaneously enhancing the activity and selectivity greatly limit the efficiency of ECO2R due to the improper interaction of reactants/intermediates on these catalytic sites. Herein, we report a carbon-based nickel (Ni) cluster catalyst containing both single-atom and cluster sites (NiNx-T, T = 500-800) through a ligand-mediated method and realize a highly active and selective electrocatalytic CO2R process. The catalytic performance can be regulated by the dispersion of Ni-N species via controlling the pyrolysis condition. Benefitting from the synergistic effect of pyrrolic-nitrogen coordinated Ni single-atom and cluster sites, NiNx-600 exhibits a satisfying catalytic performance, including a high partial current density of 61.85 mA cm-2 and a high turnover frequency (TOF) of 7,291 h-1 at -1.2 V vs. RHE, and almost 100% selectivity toward carbon monoxide (CO) production, as well as good stability under 10 h of continuous electrolysis. This work discloses the significant role of regulating the coordination environment of the transition metal sites and the synergistic effect between the isolated single-site and cluster site in enhancing the ECO2R performance.

Immunolocalization of Jian Carp (Cyprinus Carpio Var. Jian) Cathepsin B: Cloning, Expression, Characterization, and Antibody Preparation.

Cathepsin B (CatB) cDNA of 759 bp from Jian carp (Cyprinus carpio var. Jian) with amino acid similarity of 99.6% to common carp was cloned. The mature CatB was expressed in Escherichia coli BL21 transferred with vector CatB-pET-30a. It was purified and identified as a single band (29 kDa) on SDS-PAGE. Optimum CatB activity was observed at 40 °C and pH 5.5. Mouse anti-CatB polyclonal antibody with a high titer of 1:256000 was prepared successfully and shown to specifically recognize the antigen both in prokaryotic cells and in the tissues of Jian carp according to western blotting and immunohistochemistry results. Immunolocation analysis showed that CatB distribution at protein level varied among the tested tissues. The results presented in this study may provide a significant reference for future research on the inherent relationship between CatB and the quality of fish or fish products at both the gene and protein levels.

Decorating Waste Cloth via Industrial Wastewater for Tube-Type Flexible and Wearable Sodium-Ion Batteries.

To turn waste into treasure, a facile and cost-effective strategy is developed to revive electroless nickel plating wastewater and cotton-textile waste toward a novel electrode substrate. Based on the substrate, a binder-free PB@GO@NTC electrode is obtained, which exhibits superior electrochemical performance. Moreover, for the first time, a novel tube-type flexible and wearable sodium-ion battery is successfully fabricated.

Electrochemical Reduction of N2 under Ambient Conditions for Artificial N2 Fixation and Renewable Energy Storage Using N2 /NH3 Cycle.

Using tetrahexahedral gold nanorods as a heterogeneous electrocatalyst, an electrocatalytic N2 reduction reaction is shown to be possible at room temperature and atmospheric pressure, with a high Faradic efficiency up to 4.02% at -0.2 V vs reversible hydrogen electrode (1.648 µg h-1 cm-2 and 0.102 µg h-1 cm-2 for NH3 and N2 H4 ·H2 O, respectively).

Reactive Multifunctional Template-Induced Preparation of Fe-N-Doped Mesoporous Carbon Microspheres Towards Highly Efficient Electrocatalysts for Oxygen Reduction.

A novel in situ replication and polymerization strategy is developed for the synthesis of Fe-N-doped mesoporous carbon microspheres (Fe-NMCSs). This material benefits from the synergy between the high catalytic activity of Fe-N-C and the fast mass transport of the mesoporous microsphere structure. Compared to commercial Pt/C catalysts, the Fe-NMCSs show a much better electrocatalytic performance in terms of higher catalytic activity, selectivity, and durability for the oxygen reduction reaction.

Integrated Three-Dimensional Carbon Paper/Carbon Tubes/Cobalt-Sulfide Sheets as an Efficient Electrode for Overall Water Splitting.

The development of an efficient catalytic electrode toward both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of great significance for overall water splitting associated with the conversion and storage of clean and renewable energy. In this study, carbon paper/carbon tubes/cobalt-sulfide is introduced as an integrated three-dimensional (3D) array electrode for cost-effective and energy-efficient HER and OER in alkaline medium. Impressively, this electrode displays superior performance compared to non-noble metal catalysts reported previously, benefiting from the unique 3D array architecture with increased exposure and accessibility of active sites, improved vectorial electron transport capability, and enhanced release of gaseous products. Such an integrated and versatile electrode makes the overall water splitting proceed in a more direct and smooth manner, reducing the production cost of practical technological devices.

C and N Hybrid Coordination Derived Co-C-N Complex as a Highly Efficient Electrocatalyst for Hydrogen Evolution Reaction.

Development of an efficient hydrogen evolution reaction (HER) catalyst composed of earth-abundant elements is scientifically and technologically important for the water splitting associated with the conversion and storage of renewable energy. Herein we report a new class of Co-C-N complex bonded carbon (only 0.22 at% Co) for HER with a self-supported and three-dimensional porous structure that shows an unexpected catalytic activity with low overpotential (212 mV at 100 mA cm(-2)) and long-term stability, better than that of most traditional-metal catalysts. Experimental observations in combination with density functional theory calculations reveal that C and N hybrid coordination optimizes the charge distribution and enhances the electron transfer, which synergistically promotes the proton adsorption and reduction kinetics.

Gelatin-derived sustainable carbon-based functional materials for energy conversion and storage with controllability of structure and component.

Nonprecious carbon catalysts and electrodes are vital components in energy conversion and storage systems. Despite recent progress, controllable synthesis of carbon functional materials is still a great challenge. We report a novel strategy to prepare simultaneously Fe-N-C catalysts and Fe3O4/N-doped carbon hybrids based on the sol-gel chemistry of gelatin and iron with controllability of structure and component. The catalysts demonstrate higher catalytic activity and better durability for oxygen reduction than precious Pt/C catalysts. The active sites of FeN4/C (D1) and N-FeN2+2/C (D3) are identified by Mössbauer spectroscopy, and most of the Fe ions are converted into D1 or D3 species. The oxygen reduction reaction (ORR) activity correlates well with the surface area, porosity, and the content of active Fe-N x /C (D1 + D3) species. As an anode material for lithium storage, Fe3O4/carbon hybrids exhibit superior rate capability and excellent cycling performance. The synthetic approach and the proposed mechanism open new avenues for the development of sustainable carbon-based functional materials.

Artificial Protection Film on Lithium Metal Anode toward Long-Cycle-Life Lithium-Oxygen Batteries.

An artificial while very stable solid electrolyte interphase film is formed on lithium metal using an electrochemical strategy. When this protected Li anode is first used in a Li-O2 battery, the film formed on the anode can effectively suppress the parasitic reactions on the Li anode/electrolyte interface and significantly enhance the cycling stability of the Li-O2 battery.

Synergistic Effect between Metal-Nitrogen-Carbon Sheets and NiO Nanoparticles for Enhanced Electrochemical Water-Oxidation Performance.

Identifying effective means to improve the electrochemical performance of oxygen-evolution catalysts represents a significant challenge in several emerging renewable energy technologies. Herein, we consider metal-nitrogen-carbon sheets which are commonly used for catalyzing the oxygen-reduction reaction (ORR), as the support to load NiO nanoparticles for the oxygen-evolution reaction (OER). FeNC sheets, as the advanced supports, synergistically promote the NiO nanocatalysts to exhibit superior performance in alkaline media, which is confirmed by experimental observations and density functional theory (DFT) calculations. Our findings show the advantages in considering the support effect for designing highly active, durable, and cost-effective OER electrocatalysts.

ZIF-8 derived graphene-based nitrogen-doped porous carbon sheets as highly efficient and durable oxygen reduction electrocatalysts.

Nitrogen-doped carbon (NC) materials have been proposed as next-generation oxygen reduction reaction (ORR) catalysts to significantly improve scalability and reduce costs, but these alternatives usually exhibit low activity and/or gradual deactivation during use. Here, we develop new 2D sandwich-like zeolitic imidazolate framework (ZIF) derived graphene-based nitrogen-doped porous carbon sheets (GNPCSs) obtained by in situ growing ZIF on graphene oxide (GO). Compared to commercial Pt/C catalyst, the GNPCSs show comparable onset potential, higher current density, and especially an excellent tolerance to methanol and superior durability in the ORR. Those properties might be attributed to a synergistic effect between NC and graphene with regard to structure and composition. Furthermore, higher open-circuit voltage and power density are obtained in direct methanol fuel cells.