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A MOF-derived cobalt oxide/nitrogen-doped carbon composite is prepared and it exhibits remarkable performance for chlorine-assisted ethylene oxide production.

Hierarchical nickel–iron phosphide nanosheets were reported as a novel anode catalyst for direct lignin fuel cells at low temperature. When NiFeP with a Ni/Fe ratio of 1 was used, the fuel cell produced a maximum power density of 24 mW cm−2.

A unique electrocatalytic oxidative dehydrogenation of aldehydes and its facile kinetics on a Cu-based porous electrode enables an ultra-low voltage bipolar H2 production system with industrial-relevant current densities.

A product-oriented electrolyzer design offers a remarkably high nitrate-to-ammonia performance on a simple nickel electrode in an aqueous NaOH/KOH/H2O electrolyte.

Bicarbonate electrolyzer can achieve the direct conversion of CO

Electrocatalytic upgrading of biomass-derived feedstocks driven by renewable electricity offers a greener way to reduce the global carbon footprint associated with the production of value-added chemicals. In this respect, a key strategy is the electrocatalytic hydrogenation (ECH) reaction, which is typically paired with the anodic oxygen evolution reaction (OER) with sluggish kinetics, producing O2 with little value. Here we prepared an oxide-derived Ag (OD-Ag) electrode with high activity and up to 98.2% selectivity for the ECH of 5-(hydroxymethyl)furfural (HMF) to 2,5-bis(hydroxymethyl)furan (BHMF), and such efficient conversion was achieved in a three-electrode flow cell. The excellent BHMF selectivity was maintained over a broad potential range with long-term operational stability. We then considered the oxidation of HMF to 2,5-furandicarboxylic acid (FDCA) and hydrogen (to water) as more efficient and productive alternatives to the OER. In HMF-to-BHMF paired with 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-mediated HMF-to-FDCA conversion, a markedly reduced cell voltage from ∼7.5 V to ∼2.0 V was observed by transferring the electrolysis from the H-type cell to the flow cell, corresponding to more than four-fold increase in energy efficiency in operation at 10 mA. A combined faradaic efficiency of 163% was obtained for BHMF and FDCA. Alternatively, the anodic hydrogen oxidation reaction on platinum further reduced the cell voltage to only ∼0.85 V at 10 mA. These paired processes show the potential for integration of renewable electricity and carbon for green and economically feasible distributed chemical manufacturing.

Stimulated by the growing demand for sustainable and/or economical distributed ammonia synthesis, the electrochemical nitrogen reduction reaction has attracted considerable interest. The nitrogen-containing impurities in commercial metal-based nitrogen reduction reaction catalysts such as metal oxides and metallic irons have, however, been overlooked. Herein we report the presence of nitrogen-containing species in NOx− or nitrides at substantial levels revealed from many commercial catalysts. We call attention to the necessity to screen the NOx−/nitrides impurities in commercial catalysts, as the nitrogen impurities are not commonly listed in vendors’ assay documents. A simple two-step procedure (alkaline/acidic treatment followed by HPLC/UV–vis analysis) is recommended as a reliable protocol for screening NOx−/nitrides impurities in catalyst materials. A case analysis is also carried out on the previously reported H2O–NaOH–KOH system with both 15N-isotopic labelling and nitrogen elemental tracking, reassigning the true nitrogen source of the electrochemically produced NH3 from gaseous N2 to nitrogen-containing impurities in catalysts. The electrochemical nitrogen reduction reaction has recently attracted significant interest, but the true source of ammonia formation remains sometimes unclear. This Analysis reports a systematic investigation of the presence of nitrogen-containing species in a number of commercial catalysts, revealing substantial levels of NOx− and nitrides impurities for some of them.

Magnetic field- and polarization-dependent measurements on bright and dark excitons in monolayer WSe

Correction for ‘Efficient direct lignin fuel cells enabled by hierarchical nickel–iron phosphide nanosheets as an anode catalyst’ by Fei Liu et al., Sustainable Energy Fuels, 2022, 6, 4866–4872, https://doi.org/10.1039/D2SE00930G.

It is critical to fight against global warming and confine it to a manageable level of +1.5°C by curbing CO2 emissions, eventually achieving zero net emissions by 2050. This target will involve significant efforts from all industry sectors and require renewable energy storage and conversion, most of which are heavily rely on clean hydrogen production. Water electrolysis, producing hydrogen and oxygen from water and electricity, is a promising route to the decarbonization of industry and transportation. The main source of energy loss in water electrolysis is the unfavorable thermodynamics (standard potential of 1.23 V vs. NHE) and slow kinetics of oxygen evolution reaction (OER). These challenges motivate us to design efficient paired electrolysis systems to substitute OER. In this work, we demonstrate an efficient bipolar hydrogen production system that combines cathodic hydrogen evolution from water and anodic hydrogen generation from aldehyde oxidation, at a low voltage (~0.1V) with co-generation of high valuable carboxylic acid. We used furfural as the model aldehyde, a biomass-derived compound that is produced on a large scale, currently on a scale of 0.43 million tons/year. Unlike conventional combined systems for hydrogen production that require high voltage (> 1.0 V) and are limited by mass transport (−2) of reactants, this study doubled the hydrogen production rate, obtained industrial-level current density (e.g. 390 mA cm−2, 0.6V), and achieved economic viability ($2.51/kg of H2). These achievements benefit from a thermodynamically favorable hydrogen production pathway from aldehyde, facile kinetics on porous Cu-based catalysts, efficient mass transport in flow cells, and inexpensive size-exclusive separators. The successful implementation of such an energy-efficient process will impact future low-carbon hydrogen production and distributed chemical manufacturing.

Electrochemical reduction of biomass-derived feedstocks holds great promise to produce value-added chemicals or fuels driven by renewable electricity. However, mechanistic understanding of the aldehyde reduction toward valuable products at the molecular level within the interfacial regions is still lacking. Herein, through tailoring the local environments, including H/D composition and local H3O+ and H2O content, we studied the furfural reduction on Pb electrodes in acid conditions and elucidated the detailed pathways toward three key products: furfuryl alcohol (FA), 2-methylfuran (MF), and hydrofuroin. By combining isotopic labeling and electrokinetic studies, we revealed the source of protons (H2O and H3O+) plays a critical but different role in the hydrogenation and hydrogenolysis pathways toward FA and MF, respectively. In particular, the product-selective kinetic isotopic effect of H/D and the surface property-dependent hydrogenation/deuteration pathway strongly impacted the generation of FA but not MF. This is because FA and MF are produced from Langmuir-Hinshelwood and Eley-Rideal pathways, respectively. Through modifying the double layer by cations with large radii, we further correlated the product selectivity (FA and MF) qualitatively and quantitively with interfacial environments (local H3O+ and H2O content, interfacial electric field, and differential capacitances). Experimental and computational investigations further suggested competitive pathways toward hydrofuroin and FA: Hydrofuroin is favorably produced through the self-coupling of ketyl radicals in the electrolyte, which are formed from the outer-sphere single-electron transfers, while FA is generated from hydrogenation of the adsorbed furfural/ketyl radical on the electrode surface.

Ammonia (NH3) is a primary form of reactive nitrogen (Nr) which is an essential nutrient for all lives on the earth. Over the past century, the anthropological N2-fixing process in the industry (i.e., the Haber-Bosch process) has contributed to a significant portion of NH3 production, and has also led to the continued accumulation of Nr in our ecosystems that has caused alarming and profound damages to the ecosystems as well as human welfare, as the rate of Nr generation is not balanced by the natural nitrification-denitrification process for its elimination. For example, leakage of excessive nitrate (NO3 −) into the water bodies caused by overfertilization of crop fields and discharged streams from food processing facilities has led to the formation of “dead zones” in coastal areas created by eutrophication. Denitrification in nature is also accompanied by the considerable generation of nitrous oxide (N2O) which possesses century-long stability and a 300-time greater potential for greenhouse effect than CO2. Therefore, restoring the balance between the generation and elimination of Nr is a challenging but urgent task faced by our human beings today. Sustainable solutions to this human-induced matter have been actively pursued in recent years either by converting Nr to harmless N2 (i.e., denitrification), or by enhancing the effective circulation and utilization of Nr in the cycle of the nitrogen element. For instance, the electrochemical reduction of nitrate (NO3RR) is a promising approach as it can eliminate Nr without the need for additional oxidant/reductant. Selective NO3RR toward N2 is highly desirable but remains difficult to achieve due to the high activation barrier for linking two N atoms on typical catalyst surfaces, and thus the coexistence of competing pathways toward other N-containing products. Alternatively, if other forms of Nr in waste resources can be converted to NH3 in an electrochemical device, this process will not only alleviate the environmental impacts of those Nr, but also simultaneously produce NH3 that could substantially decrease the NH3 demand from the Haber-Bosch process, reduce the use of fossil-derived H2 in NH3 production, and decelerate the accumulation of Nr. In this work, we seek to develop an electricity-driven process that can convert various forms of Nr in real waste resources into manageable NH3 products. The key component is a membrane-free alkaline electrolyzer (MFAEL) which transforms Nr into NH3 as the sole N-containing product. With the inexpensive and robust MFAEL system, we achieved an ampere-level partial current density towards NH3 production. By properly choosing the conditions of NH3 collection from MFAEL, continuous production of pure NH3-based chemicals can be realized without the need for additional separation procedures. Techno-economic analysis (TEA) suggests the potential economic feasibility of the waste-to-NH3 process by coupling electrodialysis (ED) for Nr concentration and the MFAEL process for Nr conversion, offering an all-sustainable route for upcycling waste N into the highest-demanded N-based chemical product, so that the growing trend of Nr buildup can be largely decelerated and reversed.

The efficient conversion of renewable biomass to advanced carbons with high porosity and heteroatoms doping is of huge significance towards energy-related applications. However, most of the resultant carbon materials are always bulk materials with low aspect ratio and unsatisfactory electronic properties owing to the severe activation process. In this work, the KNO3 modified molten-salt (KCl/LiCl) strategy is explored to fabricate two dimensional nitrogen-doped carbon nanosheets (NCNs) by using agaric as the precursor. Benefiting from its large surface area (1376 m2 g−1), high-ratio micro-porosity (72%), high-content N doping (4 at.%) and high graphitization, the optimized NCNs sample is endowed with exceptional electrochemical capacitances both in aqueous electrolyte (6 M KOH) and organic electrolyte (1 M tetraethylammonium tetrafluoroborate/acetonitrile), when evaluated as a competitive electrode for supercapacitors. It is strongly envisioned that the method developed here holds great potential for advanced porous heteroatom-doped carbons from natural biomass for next-generation supercapacitors.

The electrochemical CO2 reduction reaction (CO2RR) has attracted enormous attention as a promising technology not only to mitigate CO2 accumulation, but also to convert CO2 into valuable chemicals and fuels.Formate/formic acid is a value-added product from CO2RR that is an important intermediate for chemical industries such as medicines, rubbers, leather and deicing materials. Moreover, it can be used as a source for hydrogen storage, transportation, as well as a fuel for direct formic acid fuel cells. Bismuth nanosheets (BiNSs) have been recognized as a promising catalyst for electrochemical CO2 reduction (CO2RR) to formate, but its preparation typically involves an elaborate synthesis of Bi-precursors under elevated temperature and pressure. Here, we have demonstrated a simple, low-cost preparation method for BiNSs by in-situ morphology transformation of Bi2O3 particles by simple electrochemical processing. SEM analysis showed that such transformation is exceedingly facile on the precipitated Bi2O3 particles compared to BiNPs and Oxi-BiNPs, revealing the crucial roles of oxygen and the initial morphology of Bi precursor in the exfoliation of BiNSs. The OD-BiNS exhibited superior CO2RR performance compared to the BiNPs and Oxi-BiNPs. 93% of FE was achieved with the current density of 62 mA cm−2 at −0.95 VRHE in the H-type cell. The enhanced CO2RR performance of OD-BiNSs can be attributed to its higher intrinsic activity and increased ECSA. 94% of FE with a high current density of 200 mA cm−2 was achieved in the flow cell, suggesting OD-BiNSs as a promising catalyst for practical applications of CO2RR. Our recent research on flow electrolytic cells for CO2 reduction will also be presented.

Electrochemical reduction of biomass-derived feedstocks holds great promise to produce value-added chemicals or fuels driven by renewable electricity. However, mechanistic understanding of the aldehyde reduction toward valuable products at the electrode/electrolyte interface at the molecular level is still lacking. Herein, we studied the furfural reduction on Pb electrodes in acid conditions and elucidated the detailed pathways toward three key products: furfuryl alcohol (FA), 2-methylfuran (MF), and hydrofuroin. First, by coupling isotopic labeling and electrokinetics, we revealed that protons (H2O and H3O+) plays an important role in the hydrogenation pathway toward FA and MF. In particular, the study of product-selective kinetic isotopic effect of H/D and the surface property-dependent hydrogenation/deuteration pathway strongly impacted the generation of FA but not MF, which can be attributed to their different formation mechanisms: FA is produced from Langmuir-Hinshelwood pathway that need both adsorbed furfural and hydrogen, but MF produced from Eley-Rideal pathway that need proton directly from the electrolyte. Modifying the double layer by cations with large radii, we further correlated the product selectivity (FA and MF) with interfacial environments (local H3O+ and H2O content, etc). Combined methods, including pulsed electrolysis, electron paramagnetic resonance (EPR) spectroscopy, and DFT calculations, further suggested that the formation of hydrofuroin and FA shared one intermediate. Hydrofuroin is produced through the desorption of the intermediate as ketyl radicals followed by its self-coupling in the electrolyte, while FA is generated from further hydrogenation of that intermediate. The acquired into the electrochemical reduction of the aldehyde group in furfural to alcohol, alkyl, and dimer may be extended to other organic compounds with carbonyl group, such as 5-hydromethylfurfural, toward a sustainable electrochemical manufacturing of higher-valued chemicals from biomass feedstock.

We report on an all-optical investigation of coupled spin excitation modes in a series of magnetic trilayer structures. Using time-resolved magneto-optic Kerr effect (tr-MOKE) magnetometry, we observe multi-mode coherent spin excitations in [Formula: see text]/Ru/[Formula: see text] multilayers even though the tr-MOKE optical detection is sensitive only to the [Formula: see text] magnetization dynamics. Frequency shifts of the different modes indicate that the coupling between the [Formula: see text] and [Formula: see text] layers varies from anti-ferromagnetic to ferromagnetic to uncoupled as the Ru spacer layer thickness is increased from 8 Å to 200 Å. The lifetime of the high frequency coherent oscillations in the [Formula: see text] layer increases by over 200%–300% even in the case of uncoupled [Formula: see text] and [Formula: see text] layers with a 200 Å thick Ru spacer. The results suggest an additional method to decrease the damping of high-moment alloys in layered magnetic nanostructures.

Potassium formate can be considered an environmentally friendly and low-corrosion deicing material. Herein we explore and develop electrochemical solutions for on-site formate production from CO₂ under ambient conditions. We screen a variety of cathode catalysts in both H-type and gas-diffusion flow-type cells, and explore several possible flow-cell device configurations with various electrolytes and membrane candidates. We demonstrate a cell capable of industrially relevant current densities (≥200 mA cm−2) while maintaining faradaic efficiency of 95% for formate and electrochemical energy efficiency >20%, and compare our results to the state-of-the-art system in the literature.

Hydrothermal carbonization (HTC) process of biomass has showed many merits for the preparation of unique carbon-based material. To overcome the challenges of inherently low porosity and conductivity associated with HTC method-prepared carbons, herein a modified hydrothermal reaction was employed to prepare hierarchically porous carbon spheres (HPCS) with large surface area by using starch as carbon precursor and ammonium ferrous sulfate as porogen. The HPCS materials exhibit excellent electrochemical performance as active materials for electric double-layer capacitors, as demonstrated by a large specific capacitance of 248 F g−1 at 0.5 A g−1, a high volumetric capacitance of 181 F cm−3 at 0.5 A g−1, good capacity retention, and excellent cycling stability. The modified hydrothermal method proposed here is promising to prepare carbon materials for wide applications.

Pairing the electrocatalytic hydrogenation reaction with different anodic reactions driven by renewable electricity offers a greener way for producing value-added chemicals and fuels. In particular, replacing the sluggish water oxidation with a biomass-based upgrading reaction can reduce the overall energy cost, thus allowing for the simultaneous generation of high-value products at both electrodes. This mini-review summarized the recent progress in paired electrolysis of biomass-derived compounds, particularly the furanic chemicals. Some perspectives and outlooks were proposed for further improvements in this research area.

In this work, ZnO-ZnFe 2 O 4 composite hollow microspheres are synthesized firstly through a facile chemical liquid method combined with the subsequent calcination processing. After the tight decoration of three dimensional graphene sheets under the assistance of cetyltrimethyl ammonium bromide surfactant, the as-harvested graphene encapsulated ZnO-ZnFe 2 O 4 composite hollow microspheres, as an anode for lithium ion batteries, deliver a relative high reversible capacity of 625 mA h g −1 after discharged/charged 300 times at 100 mA g −1 and a decent specific capacity of 461 mA h g −1 even at a large current density of 1000 mA g −1 . The modification of three dimensional graphene sheets and the well-dispersed ZnFe 2 O 4 , as well as special hollow configuration are responsible for the outstanding electrochemical properties of ZnO-based composite microspheres.

Extracting electromagnetic patterns by near field scanning can provide concrete information about a device under test (DUT), which benefits a lot when locating EMI sources. In this paper, we extracted the electromagnetic pattern of DUT under different operation state and classify the pattern with a machine learning algorithm for simplifying post-process procedure and better EMC engineering. The result showed different operation state lead to different electromagnetic emission.

In this paper, an experiment to distinguish the spatial resolution of different magnetic probes is executed. Different from traditional measuring method of spatial resolution by using one microstrip line, we measured the spatial resolution by changing two adjacent microstrip lines with space distances from 3 mm to 0.6 mm. By analyzing the test results, we can distinguish the spatial resolution of different probes.

The spatial resolution of probe is defined for a 6-dB level drop point from the peak point close to the edge of the microstrip line. However, this definition is not clear for strongly coupled traces. If the spacing between adjacent traces is small enough, the probe may not detect multiple sources. In this paper, near fields above differential microstrip lines are investigated numerically and theoretically for probe characterization of spatial resolution. Results show several limiting cases for the probe to discriminate two RF sources in close proximity. It is discovered that two traces can be easily distinguished with differential mode excitation, while the detection for the common mode excitation cases is affected by probe height and trace spacing.

In this paper, HPM is used as the source of interference to affect the working state of an integrated circuit. The effect of the injected power and the orientation of the studied integrated circuit (FPGA) is investigated. In the experiment, it is found that the induced voltage of the I/O pin can reach 70.3 V under the electromagnetic field high to 1257.44 V/m. In spite of this, the working state of the FPGA remained normal.

Paired electrolysis has been emerged as an electricity-powered platform for converting biorewable feedstock to higher-valued chemicals at both the cathode and anode. In this presentation, we explored paired electrolyzers of different architectures with remarkable performance and stability. We first designed three-electrode flow electrolyzers to pair electrocatalytic hydrogenation of 5-(hydroxymethyl)furfural (HMF) on oxide-derived silver electrode and TEMPO-mediated HMF oxidation on carbon cloth. The paired flow cell achieved a combined faradaic efficiency of 163% to desired 2,5-bis(hydroxymethyl)furan (BHMF) and 2,5-furandicarboxylic acid (FDCA) with a cell potential of ~1.7 V, at the constant current of 10 mA. When the anodic reaction was replaced by hydrogen oxidation, a minimized cell voltage of only ~0.9 V was achieved. We then assmbled a membrane electrode assembly (MEA)-based two-electrode flow cell, which realized a minimized cell potential of only ~1.5 V for a continuous 24 hours paired electrolysis of HMF. Finally, a pH asymmetric architecture was designed to match the optimum reaction conditions and to replace HMF oxidation on a NiFeOOH anode catalyst without a redox mediator. Our recent development of electrochemical-chemical combined reactors for furanic compounds conversion will also be briefly presented.

In our study, an exceptionally high selectivity of the electrocatalytic nitrate-to-nitrite transformation was discovered on Ag surfaces, among eighteen metals screened. It was demonstrated that this electrocatalytic step on oxide-derived Ag (OD-Ag), which possesses extended surface area (13 times) and enhanced specific activity (3 times) relative to Ag foil, can be coupled with a catalytic nitrite-to-dinitrogen step on a Pd catalyst using renewable hydrogen generated on-site by a water electrolyzer. We thereby proposed and demonstrated a combined electrocatalytic-catalytic process as an alternative strategy for innovative nitrate removal from agricultural wastewater with high selectivity of >95%. With future research and development, the combined process may hold the potential of tackling the ever-increasing nitrate pollution in water bodies to address its linked environmental and health issues. Strategically returning reactive nitrogen from wastewater back to the atmosphere in the inert form, this combined process is well-positioned to help close the global nitrogen cycle, one of the grand engineering challenges in the 21st century. In parallel with the applications in wastewater treatment, the Ag-based electrocatalytic nitrate-to-nitrate conversion with ultrahigh selectivity may be widely employed for designing cost-effective and energy-efficient syntheses of various nitrogen-based compounds in a distributed manufacturing fashion. The kinetics studies and computational insights could also be beneficial to advancing nitrogen-centric electrochemistry, materials science, and technologies. Figure 1

The energy-intensive Haber-Bosch process fixes around 140 million metric tons of molecular nitrogen (N2) annually worldwide into ammonia (NH3) despite its harsh conditions1. The electrochemical nitrogen reduction reaction (NRR) has been regarded as a promising alternative to the Haber-Bosch process, allowing for distributed and onsite NH3 production, and potentially can accelerate the decoupling of the ammonia industry with the use of fossil fuels2. The prosperity of NRR research under environmentally benign conditions in the past few years, however, has been challenged by the recent questioning on the source of produced NH3 in many systems3,4, due to the wide existence of active nitrogen species and the absence of direct evidence on the conversion of N2 (that is, quantitative analysis of 15NH3 production in the electrolytic experiments with 15N2). In search of effective strategies as solutions to these critical challenges, here we propose a reliable protocol for impurities screening in NRR systems. In particular, suggested procedures to examine and eliminate the N-containing species in the electrolyte salts, catalyst materials, and feeding gases will be presented based on our experimental results. We also recommend a gas circulation system for cost-effective 15N2 experiments with improved accuracy in the determination of 15NH3 production as the true N2 fixation performance. Gas permeation and co-generation of hydrogen (H2) are taken into account to ensure that 15N2 can be well confined in the system for stable long-term operation. Such a system is adaptable to different types of electrochemical reactors, making it possible for measuring and reporting 15NH3 production as a routine activity in future NRR research. References: Apodaca, L. E. Nitrogen (fixed)—Ammonia. U.S. Geological Survey, Mineral Commodity Summaries (2020). Soloveichik, G. Electrochemical synthesis of ammonia as a potential alternative to the Haber-Bosch process. Nat. Catal. 2, 377–380 (2019). Andersen, S. Z. et al. A rigorous electrochemical ammonia synthesis protocol with quantitative isotope measurements. Nature 570, 504–508 (2019). Chen, Y. et al. Revealing nitrogen-containing species in commercial catalysts used for ammonia electrosynthesis. Nat. Catal. 3, 1055–1061 (2020).

Organic electrosynthesis is emerging as a cost-effective and environmental-friendly chemical production strategy by utilizing renewable electricity. Paired electrolysis cogenerates valuable chemicals at both electrodes can optimize the energy efficiency and economic feasibility. We report pairing hydrogenation and oxidation of 5-(hydroxymethyl)furfural (HMF) or furfural to desired chemicals at a single electrolysis cell. Electrocatalytic hydrogenation of HMF to 2,5-bis(hydroxymethyl)furan (BHMF) and furfural to furfural alcohol (FA) with high selectivity of >90% can be operated at near-neutral pH on Ag-based and Pb-based catalysts, respectively. In addition, oxidizing HMF to 2,5-furandicarboxylic acid (FDCA) and furfural to furoic acid can both be realized at TEMPO mediated process by using carbon-based catalysts or at Ni-based catalyst in an alkaline medium. Taken together, HMF or furfural can be performed in a single electrolysis cell with a minimized cell voltage only around 1.6 V. Products selectivity and faradaic efficiency are highly related to the reaction conditions, including potential or current density, architectures of the reactor, type of catalysts. By optimizing the single flow reactor, a three-electrode system, two-electrode membrane assembly architecture, and pH-symmetric and pH-asymmetric structure can be designed to reduce the capital expense, minimize required energy, and simplify processing steps. Finally, a complete electrons economy can be achieved by pairing two electrochemical reactions, and the overall charge efficiency can attain over 170% without any crossover issue detected. As a result, the continuous cogeneration of high value-added BHMF or FA and FDCA or furoic acid can be performed in a single electrolyzer.

3C-SiC powders are synthesized successfully by using metallic Na, Si powder and CHI3 as raw materials. The samples are characterized by XRD, FTIR, Raman, TEM, SEM, and luminescence spectroscopy. The XRD patterns, FTIR and Raman spectra indicate that the obtained samples have the cubic phase. The SEM and TEM images suggest that the samples are nano-wires and micro-polyhedra, when different chemical reagents are added in the synthesis. The mean diameter of nano-wires is about 20 nm and the length is about several µm. And the sizes of micro-polyhedra are in the range of 2–5 µm. The two samples show emission band peaking at 395 and 433 nm under the excitation of 220 nm.