Novel mechanisms for electromagnetic wave emission in the terahertz frequency regime emerging at the nanometer scale have recently attracted intense attention for the purpose of searching next-generation broadband THz emitters. Here, we report broadband THz emission, utilizing the interface inverse Rashba-Edelstein effect. By engineering the symmetry of the Ag/Bi Rashba interface, we demonstrate a controllable THz radiation (∼0.1-5  THz) waveform emitted from metallic Fe/Ag/Bi heterostructures following photoexcitation. We further reveal that this type of THz radiation can be selectively superimposed on the emission discovered recently due to the inverse spin Hall effect, yielding a unique film thickness dependent emission pattern. Our results thus offer new opportunities for versatile broadband THz radiation using the interface quantum effects.

We perform systematic first-principles calculations to investigate the spin-phonon coupling (SPC) of Cr2Ge2Te6 (CGT) monolayer (ML). It is found that the Eg phonon mode at 211.8 cm -1 may have a SPC as large as 3.19 cm -1 , as it directly alters the superexchange interaction along the Cr-Te-Cr pathway. Furthermore, the strength of SPC of the CGT ML can be further enhanced by an in-plane compressive strain. These results provide useful insights for the understanding of SPC in novel two-dimensional magnetic semiconductors and may guide the design of spintronic and spin Seebeck materials and devices.In Eq. (2) and (3), spin S for each Cr atom is 3/2. Our calculations show that 1 J =4.92 meV, 2 J =-0.31 meV, and 3 J =0.01 meV, which agrees well with previous studies [15,37]. The large FM 1 J results from the competition between the direct exchange between Cr-Cr sites and the superexchange mediated through the Te ions, and strongly depends on the Cr-Cr distance. It is conceivable that J1 changes when the CGT lattice is either stretched or compressed. This is confirmed in Fig. 2(a) which shows that 1 J , 2 J and 3 J increase rapidly with lattice expansion in a range from 6.69 Å to 6.97 Å. Especially, the slope of the black curve in Fig. 2(a) indicates that the coefficient of the variation of J1 with lattice expansion is as large as 21.13 meV/Å. Furthermore, it is obvious that the FM state becomes more stable when the lattice is

Two-dimensional quantum spin Hall (QSH) insulators with reasonably wide band gaps are imperative for the development of various innovative technologies. Through systematic density functional calculations and tight-binding simulations, we found that stanene on α-alumina surface may possess a sizeable topologically nontrivial band gap (~0.25 eV) at the Γ point. Furthermore, stanene is atomically bonded to but electronically decoupled from the substrate, providing high structural stability and isolated QSH states to a large extent. The underlying physical mechanism is rather general, and this finding may lead to the opening of a new vista for the exploration of QSH insulators for room temperature device applications.

Developing highly efficient, selective and low-overpotential electrocatalysts for carbon dioxide (CO2) reduction is crucial. This study reports an efficient Ni single-atom catalyst coordinated with pyrrolic nitrogen and pyridinic nitrogen for CO2 reduction to carbon monoxide (CO). In flow cell experiments, the catalyst achieves a CO partial current density of 20.1 mA cmgeo−2 at −0.15 V vs. reversible hydrogen electrode (VRHE). It exhibits a high turnover frequency of over 274,000 site−1 h−1 at −1.0 VRHE and maintains high Faradaic efficiency of CO (FECO) exceeding 90% within −0.15 to −0.9 VRHE. Operando synchrotron-based infrared and X-ray absorption spectra, and theoretical calculations reveal that mono CO-adsorbed Ni single sites formed during electrochemical processes contribute to the balance between key intermediates formation and CO desorption, providing insights into the catalyst’s origin of catalytic activity. Overall, this work presents a Ni single-atom catalyst with good selectivity and activity for CO2 reduction while shedding light on its underlying mechanism.

In recent years, there has been significant interest in the development of twodimensional (2D) nanomaterials with unique physicochemical properties for various energy applications. These properties are often derived from the phase structures established through a range of physical and chemical design strategies. A concrete analysis of the phase structures and real reaction mechanisms of 2D energy nanomaterials requires advanced characterization methods that offer valuable information as much as possible. Here, we present a comprehensive review on the phase engineering of typical 2D nanomaterials with the focus of synchrotron radiation characterizations. In particular, the intrinsic defects, atomic doping, intercalation, and heterogeneous interfaces on 2D nanomaterials are introduced, together with their applications in energy-related fields. Among them, synchrotron-based multiple spectroscopic techniques are emphasized to reveal their intrinsic phases and structures. More importantly, various in situ methods are employed to provide deep insights into their structural evolutions under working conditions or reaction processes of 2D energy nanomaterials. Finally, conclusions and research perspectives on the future outlook for the further development of 2D energy nanomaterials and synchrotron radiation light sources and integrated techniques are discussed.

Antibacterial dynamic therapy (ADT) triggered by reactive oxygen species (ROS) is promising for diabetic infectious disease treatment. However, the limited local O 2 /H 2 O 2 production and post-treatment inflammation remain long-standing issues. To address these challenges, a novel H 2 -evolving bio-heterojunction enzyme (Bio-HJzyme) consisting of graphite-phase carbon nitride/copper sulfide (CN/Cu 2−x S) heterojunction and glucose oxidase (GOx) is created. The Bio-HJzyme offers glutathione peroxidase (GPx), peroxidase (POD), and catalase (CAT) mimetic activities; provides anti-pathogen properties via programmed light activation; and effectively promotes diabetic wound healing. Specifically, its GPx-mimetic activity and the presence of GOx significantly enhance the yield of H 2 O 2 , which can be catalyzed through POD-mimetic activity to produce highly germicidal •OH. The H 2 O 2 can also be catalyzed to H 2 O and O 2 , assisted by the CAT-mimetic activity. The catalyzed products can then be catalyzed into germicidal •OH and •O 2 − under NIR light irradiation, giving enhanced ADT. Further, CN can split water to form H 2 under solar light, which dramatically suppresses the inflammation caused by excessive ROS. In vivo evaluation confirms that Bio-HJzyme promotes the regeneration of diabetic infectious skin through killing bacteria, enhancing angiogenesis, promoting wound bed epithelialization, and reinforcing anti-inflammatory responses; hence, providing a revolutionary approach for diabetic wounds healing.

Topological insulators hold great potential for efficient information processing and storage. Using density functional theory calculations, we predict that a honeycomb lead monolayer can be stabilized on an AlO (0001) substrate to become topologically non-trivial with a sizeable band gap (∼0.27 eV). Furthermore, we propose to use a hexagonal boron-nitride (h-BN) monolayer as a protection for the topological states of Pb/AlO and Sn/AlO. Our findings suggest new possibilities for designing and protecting two-dimensional TIs for practical applications.

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