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Designing an excellent acidic and alkaline general-purpose hydrogen evolution electrocatalyst plays an important role in promoting the development of the energy field. Here, a feasible strategy is reported to use the strongly coupled MoS2@sulfur and molybdenum co-doped g-C3N4 (MoS2@Mo-S-C3N4) heterostructure with transferable active centers for catalytic reactions in acidic and alkaline media. Research studies have shown that the unsaturated S site at the edge of MoS2 and the active N atom on the Mo-S-C3N4 substrate are, respectively, the active centers of acidic and alkaline hydrogen evolution reaction. Specifically, Mo-S-C3N4 is regarded as a synergistic catalyst for the active species MoS2 in acidic hydrogen evolution, while MoS2 acts as a co-catalyst when the alkaline active species are transferred to Mo-S-C3N4. The coordination of the electrons between the interfaces achieves a synergistic balance, which provides the optimal sites for the adsorption of the reactants. Such an electrocatalyst exhibits overpotentials of 193 and 290 mV at 10 mA cm–2 in 0.5 M H2SO4 and 1 M KOH, respectively, which was better than numerous previous reports. This research provides an outstanding avenue to realize multifunctional electrocatalysts.

Metamaterials are composed of periodic or quasi‐periodic subwavelength structures, having electric and/or magnetic responses. Metamaterials can arbitrarily tailor the refractive index by artificially tailoring the unit‐cell geometries and dimensions. Recent years, as the two dimensional equivalent of bulk metamaterials, metasurfaces have caused considerable attentions due to the lower profile and simpler to fabricate than bulk metamaterials. Metasurfaces can impart discontinuities on electromagnetic wavefronts and can achieve the arbitrary transmission phase of the whole period range. Metamaterials and metasurfaces have led to the realizations of novel electromagnetic properties and functionalities through tailoring subwavelength structures and integrating functional materials. In this letter, two planar lenses are respectively proposed to control the beam direction of the horn antenna by using a gradient refractive index (GRIN) metamaterial and a gradient phase (GRPH) metasurface. It is shown that the antenna beam direction can be steered by controlling the refractive index of the GRIN metamaterial or the transmission phase of the GRPH metasurface. The differences between the two planar lenses for controlling the antenna beam are illustrated.