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In this report, we propose to enhance the hole injection efficiency by adjusting the barrier height of the p-type electron blocking layer (p-EBL) for ∼273 nm deep ultraviolet light-emitting diodes (DUV LEDs). The barrier height for the p-EBL is modified by employing a p-Al 0.60 Ga 0.40 N/ Al 0.50 Ga 0.50 N/p-Al 0.60 Ga 0.40 N structure, in which the very thin Al 0.50 Ga 0.50 N layer is able to achieve a high local hole concentration, which is very effective in reducing the effective barrier height of the p-EBL for holes. More importantly, besides the thermionic emission, such a p-EBL structure can also favor a strong intraband tunneling process for holes. As a result, we can obtain a more efficient hole injection into the quantum wells, leading to a remarkably improved optical power for the DUV LED with the proposed p-EBL architecture.

Exploiting high-efficiency and low-cost bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has been actively encouraged because of their potential applications in the field of clean energy. In this paper, we reported a novel electrocatalyst based on an exfoliated two-dimensional (2D) MXene (TiCT ) loaded with bimetallic oxide alloy nanoparticles (NPs) of Pt and Pd (represented by PtOPdO NPs@TiCT ), which was synthesized via solution plasma (SP) modification. The prepared materials were then utilized as highly efficient bifunctional electrocatalysts toward the HER and OER in alkaline solution. At a high plasma input power (200 W), bimetallic oxide alloy nanoparticles of Pt and Pd or nanoclusters with different metallic valence states were deposited onto the TiCT nanosheets. Because of the synergism of the noble-metal NPs and the TiCT nanosheets, the electrocatalytic results revealed that the as-prepared PtOPdO NPs@TiCT nanosheets under the plasma input power of 200 W for 3 min only required a low overpotential to attain 10 mA cm for the HER (-26.5 mV) in 0.5 M HSO solution and OER (1.54 V) in 0.1 M KOH solution. Moreover, water electrolysis using this catalyst achieved a water splitting current density of 10 mA cm at a low cell voltage of 1.53 V in 1.0 M KOH solution. These results suggested that the hybridization of the extremely low usage of PtO /PdO NPs (1.07 μg cm) and TiCT nanosheets by SP will expand the applications of other clean energy reactions to achieve sustainable energy.

Hierarchical and hollow porous FeO nanoboxes (with an average edge length of ∼500 nm) were derived from metal-organic frameworks (MOFs) and the gas sensing characteristics were investigated. Sensors based on FeO nanoboxes exhibited a response (resistance ratio) of 1.23 to 0.25 ppm (ppm) hydrogen sulfide (HS) at 200 °C, the response/recovery speed is fast and the selectivity to HS is excellent. Remarkably, the sensor showed fully reversible response to 5 ppm of HS at 50 °C, demonstrating its promise for operating at near room temperature, which is favorable for medical diagnosis and indoor/outdoor environment monitoring. The excellent performance of the FeO nanoboxes can be ascribed to the unique morphology with high specific surface area (SSA) and porous nanostructure.