Abstract-A new L-shaped chiral structure working in microwave and optical frequency bands has been designed and simulated. The circular dichroism, ellipticity angle, polarization azimuth rotation angle, and effective parameters of this structure, including relative permittivity, relative permeability, chiral parameter and refractive index, are retrieved from simulated transmission and reflection spectra. The results show that the exceptionally strong optical activity is found for the L-shaped chiral structure. Because of the large chiral parameter of this structure, negative refractive index of one circularly polarized wave can be obtained without simultaneously negative permittivity and negative permeability.

Electrochemical CO 2 reduction to formate offers a mild and feasible pathway for the utilization of CO 2 , and bismuth is a promising metal for its unique hydrogen evolution reaction inhibition. Reported works of Bi-based electrodes generally exhibit high selectivity while suffering from relatively narrow working potential range. From the perspective of electronic modification engineering, B-doped Bi is prepared by a facile chemical reduction method in this work. With B dopant, above 90% Faradaic efficiency for formate over a broad window of working potential of −0.6 to −1.2 V (vs. reversible hydrogen electrode) is achieved. In situ Raman spectroscopy, X-ray adsorption spectroscopy, and computational analysis demonstrate that the B dopant induces the formation of electron-rich bismuth, which is in favor of the formation of formate by fine-tuning the adsorption energy of *OCHO. Moreover, full-cell electrolysis system coupled with photovoltaic device is constructed and achieves the solar-to-formate conversion efficiency as high as 11.8%.

Abstract-The characteristics of guided modes in the four-layer slab waveguide containing chiral nihility core have been investigated theoretically.The characteristic equation of guided modes is derived. The dispersion curves, energy flux and normalized power of guided modes for three cases of chiral metamaterial parameters are presented. Some abnormal features are found, such as the existence of fundamental mode and surface wave mode, unusual dispersion curves, positive energy flux in the chiral nihility core, and zero power at some normalized frequencies.

The slow kinetics of oxygen evolution reaction (OER) catalysts with a large overpotential restricts the feasibility of electrochemical water splitting. Iron based electrodes are attractive candidates, but elevating their activity faces great challenges in weak intermediate adsorption. Herein, we demonstrated that ultrathin FeP nanosheets with Fe defects on nickel foam (FeP-NS/NF) exhibited a remarkable electrocatalytic oxygen evolution performance. The overpotential of FeP-NS/NF only requires 220 mV to achieve a current density of 10 mA cm −2 in 1 M KOH solution. Moreover, it possessed excellent durability during the 85 h stability test. Fe defects over ultrathin FeP evidenced by X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) have been experimentally demonstrated to promote oxygenated intermediate adsorption, which largely reduce the overpotential of OER.