We present a dark matter model to explain the excess events in the electron recoil data recently reported by the Xenon1T experiment. In our model, dark matter annihilates into a pair of on-shell particles , which subsequently decay into the final state; interacts with electrons to generate the observed excess events. Because of the mass hierarchy, the velocity of can be rather large and can have an extended distribution, providing a good fit to the electron recoil energy spectrum. We estimate the flux of from dark matter annihilations in the galaxy and further determine the interaction cross section, which is sizable but sufficiently small to allow to penetrate the rocks to reach the underground labs.

Excessive emission of CO2 leads to global warming, and CO2 reduction is a promising method to utilize excessive emission. Light-driven reactions, including photoelectro­chemical (PEC) and photochemical (PC) systems, have been widely investigated, which can convert solar energy into chemical energy. In this review, the mechanism of CO2 reduction is discussed based on density functional theory (DFT) calculation and comparisons are also made in the representative light-driven devices. Also, the characteristics of candidate materials, such as semiconductors, metal organic frameworks (MOFs), layered double hydroxides (LDHs), and zeolites, etc., are included in details to explain how these characteristics influence the process of CO2 adsorption, activation, and desorption. Besides, several strategies to improve the efficiency and selectivity of catalytic reaction are also summarized. Finally, the challenges and outlook of light-driven reaction for CO2 reduction are presented.

Single-electron capture in 14 keV q−1 Ar15+…18++He collisions is investigated both experimentally and theoretically. Partial cross sections and projectile scattering angle dependencies have been deduced from the target ion recoil momenta measured by the COLTRIMS technique. The comparison with close-coupling results obtained from a two-centre extension of the basis generator method yields good overall agreement, demonstrating the applicability of close-coupling calculations to collision systems involving highly charged ions in charge states up to 18+.

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Photoelectrochemical (PEC) reduction of CO2 to high value-added chemicals or fuel is an effective way to remit insufficient energy supply and global warming. Herein, Bi species-modified p-n heterojunction ZnO/p-Si was synthesized by a hydrothermal method and a subsequent electrodeposition process. For the PEC CO2 reduction reaction (CO2RR), the obtained photocathode Bi-Bi2O3/ZnO/p-Si not only improves the light absorption capacity because of p-Si and plasma metal Bi, but also increases the selectivity of CO2 reduction products because of the existence of Bi species. In particular, compared with the electrochemical CO2RR, the faraday efficiency of formate shows a 1.8 fold increase for the optimal sample Bi-Bi2O3/ZnO/p-Si reaching 84.3% in the PEC CO2RR at −0.95 V vs RHE. More importantly, the current density and product selectivity have no decay within 8 h, implying its high stability. In addition,, a high applied bias photon-to-current efficiency of 1.14% and an energy efficiency value of 56.21% were achieved for the Bi-Bi2O3/ZnO/p-Si photocathode at −0.95 V vs RHE, confirming its high PEC activity. A possible electron transfer mechanism for the Bi-Bi2O3/ZnO/p-Si photocathode is also proposed.

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Using renewable energy to convert CO2 into liquid products, as a sustainable way to produce fuels and chemicals, has attracted intense attention. Herein, a novel heterostructured photocathode composed of Si wafer, TiO2 layer, and Sn metal particles has been successfully fabricated by combining of a facile hydrothermal and electrodeposition method. The obtained Sn/TiO2/Si photocathode shows enhanced light absorption performance by the surface plasmon resonance effect of Sn metal. Especially, the Sn/TiO2/Si photocathode together with rich oxygen vacancy defects jointly promote photoelectrochemical CO2 reduction, harvesting a high faradaic efficiency of HCOOH and a desirable average current density (−4.72 mA cm−2) at −1.0 V vs. reversible hydrogen electrode. Significantly, the photocathode Sn/TiO2/Si also shows good stability due to the design of protecting layer TiO2. This study provides a facile strategy of constructing an efficient photocathode to improve the light absorption performance and the electron transfer efficiency, exhibiting great potential in the CO2 reduction.

Converting CO2 into high‐value liquid products is a promising strategy to alleviate energy crisis. Herein, a novel Cu/Bi bi‐metal catalyst derived from MOFs has been prepared by a hydrothermal synthesis combining with high temperature calcination under N2 atmosphere, which shows cylindrical morphology composed of bi‐metallic nanoparticles. It is found that Cu/Bi bi‐metallic system is beneficial to lower the activate energy barrier of CO2 and shows a stronger adsorption capability for the CO2 ⋅ − intermediate than that of reference Bi/Bi2O3@C without Cu species. XPS analysis indicates the boosted performance for CO2 reduction reaction, which could be ascribed to synergistic coordination of Bi0 and Bi3+ in the catalyst. The optimized Cu1−Bi/Bi2O3@C exhibits excellent selectivity toward HCOOH with faradaic efficiency (FE) exceeding 84 % between −0.84 and −1.14 V vs. RHE, and even reaching 93 % at −0.94 V vs. RHE. The obtained Cu/Bi bi‐metal catalyst shows a promising application prospect in the CO2 reduction.