Conversion of carbon dioxide (CO2) into fuels is an attractive solution to many energy and environmental challenges. However, the chemical inertness of CO2 renders many electrochemical and photochemical conversion processes inefficient. We report a transition metal dichalcogenide nanoarchitecture for catalytic electrochemical CO2 conversion to carbon monoxide (CO) in an ionic liquid. We found that tungsten diselenide nanoflakes show a current density of 18.95 milliamperes per square centimeter, CO faradaic efficiency of 24%, and CO formation turnover frequency of 0.28 per second at a low overpotential of 54 millivolts. We also applied this catalyst in a light-harvesting artificial leaf platform that concurrently oxidized water in the absence of any external potential.

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The development of an efficient catalyst system for the electrochemical reduction of carbon dioxide into energy-rich products is a major research topic. Here we report the catalytic ability of polyacrylonitrile-based heteroatomic carbon nanofibres for carbon dioxide reduction into carbon monoxide, via a metal-free, renewable and cost-effective route. The carbon nanofibre catalyst exhibits negligible overpotential (0.17 V) for carbon dioxide reduction and more than an order of magnitude higher current density compared with the silver catalyst under similar experimental conditions. The carbon dioxide reduction ability of carbon nanofibres is attributed to the reduced carbons rather than to electronegative nitrogen atoms. The superior performance is credited to the nanofibrillar structure and high binding energy of key intermediates to the carbon nanofibre surfaces. The finding may lead to a new generation of metal-free and non-precious catalysts with much greater efficiency than the existing noble metal catalysts.

Electrochemistry is central to applications in the field of energy storage and generation. However, it has advanced far more slowly over the last two decades, mainly because of a lack of suitable and affordable catalysts. Here, we report the synthesis of highly crystalline layered three-dimensional (3D) molybdenum disulfide (MoS2) catalysts with bare Mo-edge atoms and demonstrate their remarkable performance for the hydrogen evolution reaction (HER). We found that Mo-edge-terminated 3D MoS2 directly grown on graphene film exhibits a remarkable exchange current density (18.2 μA cm–2) and turnover frequency (>4 S–1) for HER. The obtained exchange current density is 15.2 and 2.3 times higher than that of MoS2/graphene and MoS2/Au catalysts, respectively, both with sulfided Mo-edge atoms. An easily scalable and robust growth process on a wide variety of substrates, along with prolonged stability, suggests that this material is a promising catalyst in energy-related applications.

This research focused on improving mineralization rates during the advanced electrochemical oxidation treatment of agricultural water contaminants. For the first time, bismuth-doped tin oxide (BDTO) catalysts were deposited on Magneĺi phase (Ti n O 2n−1 , n = 4−6) reactive electrochemical membranes (REMs). Terephthalic acid (TA) was used as a OH • probe, whereas atrazine (ATZ) and clothianidin (CDN) were chosen as model agricultural water contaminants. The BDTO-deposited REMs (REM/BDTO) showed higher compound removal than the REM, due to enhanced OH • production. At 3.5 V/SHE, complete mineralization of TA, ATZ, and CDN was achieved for the REM/BDTO upon a single pass in the reactor (residence time ∼3.6 s). Energy consumption for REM/BDTO was as much as 31-fold lower than the REM, with minimal values per log removal of <0.53 kWh m −3 for TA (3.5 V/SHE), <0.42 kWh m −3 for ATZ (3.0 V/SHE), and 0.83 kWh m −3 for CDN (3.0 V/ SHE). Density functional theory simulations provided potential dependent activation energy profiles for ATZ, CDN, and various oxidation products. Efficient mass transfer and a reaction mechanism involving direct electron transfer and reaction with OH • were responsible for the rapid and complete mineralization of ATZ and CDN at very short residence times.