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Neutrinoless double beta decay (0νββ) provides a way to probe physics beyond the Standard Model of particle physics. The upcoming nEXO experiment will search for 0νββ decay in 136Xe with a projected half-life sensitivity exceeding 1028 years at the 90% confidence level using a liquid xenon (LXe) Time Projection Chamber (TPC) filled with 5 tonnes of Xe enriched to ∼90% in the ββ-decaying isotope 136Xe. In parallel, a potential future upgrade to nEXO is being investigated with the aim to further suppress radioactive backgrounds and to confirm ββ-decay events. This technique, known as Ba-tagging, comprises extracting and identifying the ββ-decay daughter 136Ba ion. One tagging approach being pursued involves extracting a small volume of LXe in the vicinity of a potential ββ-decay using a capillary tube and facilitating a liquid-to-gas phase transition by heating the capillary exit. The Ba ion is then separated from the accompanying Xe gas using a radio-frequency (RF) carpet and RF funnel, conclusively identifying the ion as 136Ba via laser-fluorescence spectroscopy and mass spectrometry. Simultaneously, an accelerator-driven Ba ion source is being developed to validate and optimize this technique. The motivation for the project, the development of the different aspects, along with the current status and results, are discussed here. 

Direct electrochemical halogenation has appeared as an appealing approach in synthesizing organic halides in which inexpensive inorganic halide sources are employed and electrical power is the sole driving force. However, the intrinsic characteristics of direct electrochemical halogenation limit its reaction scope. Herein, we report an on-site halogenation strategy utilizing halogen gas produced from halide electrolysis while the halogenation reaction takes place in a reactor spatially isolated from the electrochemical cell. Such a flexible approach is able to successfully halogenate substrates bearing oxidatively labile functionalities, which are challenging for direct electrochemical halogenation. In addition, low-polar organic solvents, redox-active metal catalysts, and variable temperature conditions, inconvenient for direct electrochemical reactions, could be readily employed for our on-site halogenation. Hence, a wide range of substrates including arenes, heteroarenes, alkenes, alkynes, and ketones all exhibit excellent halogenation yields. Moreover, the simultaneously generated H 2 at the cathode during halide electrolysis can also be utilized for on-site hydrogenation. Such a strategy of paired halogenation/hydrogenation maximizes the atom economy and energy efficiency of halide electrolysis. Taking advantage of the on-site production of halogen and H 2 gases using portable halide electrolysis but not being suffered from electrolyte separation and restricted reaction conditions, our approach of flexible halogenation coupled with hydrogenation enables green and scalable synthesis of organic halides and value-added products. 

Despite the increasing interest in upgrading biomass-derived molecules to value-added products, the electrochemical conversion of biomass platform chemicals to highly valuable biofuels, such as jet fuel, has not yet received wide attention. Herein, we report a catalyst-free electrochemical route for the production of a jet fuel precursor, hydrofuroin, from the electrohydrodimerization of furfural, which can be readily derived from lignocellulose and already has an industrial production of 300 000 tons per year. Detailed electrochemical studies using carbon and copper electrodes at various pH values enabled us to probe the reduction mechanism of furfural and obtain the kinetic details, such as the diffusion constant and electron transfer rate. Preparative electrolysis in a batch electrolyzer achieved a high yield of hydrofuroin (94%) with an excellent faradaic efficiency of 93%. Finally, a flow electrolyzer was employed to demonstrate the great promise of large-scale production of hydrofuroin from the electrohydrodimerization of furfural. 

Electrocatalytic water splitting to produce clean hydrogen is a promising technique for renewable energy conversion and storage in the future energy portfolio. Aiming at industrial hydrogen production, cost-effective electrocatalysts are expected to be competent in both hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs) to accomplish the overall water splitting. Limited by the low tolerance and/or poor activity of most 1st-row transition metal-based electrocatalysts in strongly acidic media, bifunctional electrocatalysts are currently advocated to work at high pH values. Herein, this review summarizes the recent progress of nonprecious bifunctional electrocatalysts for overall water splitting in alkaline media, including transition metal-based phosphides, chalcogenides, oxides, nitrides, carbides, borides, alloys, and metal-free materials. Besides, some prevalent modification strategies to optimize the activities of catalysts are briefly listed. Finally, the perspective on current challenges and future prospects for overall water splitting driven by advanced nonprecious electrocatalysts are briefly discussed.