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Heterostructure engineering is crucial for enhancing gas sensing performance. However, achieving rapid response for room-temperature NO 2 sensing through rational heterostructure design remains a challenge. In this study, a Bi 2 Se 3 /SnSe 2 2D/2D heterostructure was synthesized by hydrothermal method for the rapid detection of NO 2 at room temperature. By combining Bi 2 Se 3 nanosheets with SnSe 2 nanosheets, the Bi 2 Se 3 /SnSe 2 sensor demonstrated and the lowest detection limit for NO 2 a short response time (15 s) to 10 ppm NO 2 at room temperature, reaches 25 ppb. Furthermore the sensor demonstrates significantly larger response to NO 2 than to other interfering gases, including 10 ppm NO 2 , H 2 S, NH 3 , CH 4 , CO, and SO 2 ,demonstrating its outstanding selectivity. And we discuss the mechanism of related performance enhancement., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Yi, Chen, Yu, Hao and Wang.)

Highly-aligned flake graphite (FG) reinforced Cu matrix composites with high thermal conductivity and adaptive coefficient of thermal expansion were successfully prepared via the collaborative process of tape-casting and hot-pressing sintering. To overcome the problem of fragile interface, Zr-Cu alloy powder was introduced instead of pure Zr powder to enhance the interfacial strength, ascribed to the physical-chemical bonding at the Cu-FG interface. The results indicate that the synthetic ZrC as interfacial phase affects the properties of FG/Cu composites. The thermal conductivity reaches the maximum value of 608.7 W/m∙K (52% higher than pure Cu) with 0.5 wt % Zr. Surprisingly, the negative coefficient of thermal expansion (CTE) in the Z direction is acquired from -7.61 × 10 -6 to -1.1 × 10 -6 /K with 0 to 2 wt % Zr due to the physical mechanism of strain-engineering of the thermal expansion. Moreover, the CTE in X-Y plane with Zr addition is 8~10 × 10 -6 /K, meeting the requirements of semiconductor materials. Furthermore, the bending strength of the FG/Cu-2 wt % Zr composite is 42% higher than the FG/Cu composite. Combining excellent thermal conductivity with ultralow thermal expansion make the FG/Cu-Zr composites be a highly promising candidate in the electronic packaging field.

The widespread use of electronic equipment, such as computers, cell phones, communication devices and wireless facilities, has increased electromagnetic radiation, which can cause cancer and other diseases in humans. Furthermore, there is an urgent need for excluding the interferences in the aircraft and other precise instruments in military aspects. Therefore, minimizing and attenuating electromagnetic waves are critical issues. In this review, various two-dimensional (2D) materials and structures are discussed for microwave-absorbing and shielding in terms of 'thin, light, wide, and strong' requirements. The typical absorption and attenuation mechanisms are analysed and summarized to deliver an overall view and offer possible trends for future developments. Multiple works have revealed that 2D materials and structures are promising for use in microwave devices. In addition to conventional materials with 2D structures, we focus on new graphene-like materials, such as 2D transition metal dichalcogenides and black phosphorus, due to their beneficial absorbing and shielding properties. These 2D materials will likely play an important role in electromagnetic wave absorption and cancellation in the future. Finally, the related challenges and some new 2D materials are briefly discussed.