Yongsong Luo

Sensitivity of the sensor is of great importance in practical applications of wearable electronics or smart robotics. In the present study, a capacitive sensor enhanced by a tilted micropillar array-structured dielectric layer is developed. Because the tilted micropillars undergo bending deformation rather than compression deformation, the distance between the electrodes is easier to change, even discarding the contribution of the air gap at the interface of the structured dielectric layer and the electrode, thus resulting in high pressure sensitivity (0.42 kPa–1) and very small detection limit (1 Pa). In addition, eliminating the presence of uncertain air gap, the dielectric layer is strongly bonded with the electrode, which makes the structure robust and endows the sensor with high stability and reliable capacitance response. These characteristics allow the device to remain in normal use without the need for repair or replacement despite mechanical damage. Moreover, the proposed sensor can be tailored to any size and shape, which is further demonstrated in wearable application. This work provides a new strategy for sensors that are required to be sensitive and reliable in actual applications.

Abstract MXenes have attracted great interests as supercapacitors due to their metallic conductivity, high density, and hydrophilic nature. Herein we report Ti 3 C 2 ‐Cu/Co hybrids via molten salt etching in which the existence of metal atoms and their interactions with MXene via surficial O atoms were elucidated by XAFS for the first time. The electrochemical investigation of Ti 3 C 2 ‐Cu electrode demonstrated the pseudocapacitive contribution of Cu and a splendid specific capacitance of 885.0 F g −1 at 0.5 A g −1 in 1.0 M H 2 SO 4 . Symmetric supercapacitor Ti 3 C 2 ‐Cu//Ti 3 C 2 ‐Cu was demonstrated with operating voltage of 1.6 V, areal capacitance of 290.5 mF cm −2 at 1 mA cm −2 , and stability over 10 000 cycles. It delivered an areal energy density of 103.3 μWh cm −2 at power density of 0.8 mW cm −2 , based on which a supercapacitor pouch was fabricated. It provides deeper insights into the molten salt mechanism and strategies for designing MXene‐based materials for electrochemical energy storage.

Highly ordered TiO2@α-Fe2O3 core/shell arrays on carbon textiles (TFAs) have been fabricated by a stepwise, seed-assisted, hydrothermal approach and further investigated as the anode materials for Li-ion batteries (LIBs). This composite TFA anode exhibits superior high-rate capability and outstanding cycling performance. The specific capacity of the TFAs is much higher than that of pristine carbon textiles (CTs) and TiO2 nanorod arrays on carbon textiles (TRAs), indicating a positive synergistic effect of the material and structural hybridization on the enhancement of the electrochemical properties. This composite nanostructure not only provides large interfacial area for lithium insertion/extraction but should also be beneficial in reducing the diffusion pathways for electronic and ionic transport, leading to the improved capacity retention on cycling even at high discharge–charge rates. It is worth emphasizing that the CT substrates also present many potential virtues for LIBs as flexible electronic devices owing to the stretchable, lightweight and biodegradable properties. The fabrication strategy presented here is facile, cost-effective, and scalable, which opens new avenues for the design of optimal composite electrode materials for high performance LIBs.

In this paper, a highly ordered three‐dimensional Co 3 O 4 @MnO 2 hierarchical porous nanoneedle array on nickel foam is fabricated by a facile, stepwise hydrothermal approach. The morphologies evolution of Co 3 O 4 and Co 3 O 4 @MnO 2 nanostructures upon reaction times and growth temperature are investigated in detail. Moreover, the as‐prepared Co 3 O 4 @MnO 2 hierarchical structures are investigated as anodes for both supercapacitors and Li‐ion batteries. When used for supercapacitors, excellent electrochemical performances such as high specific capacitances of 932.8 F g −1 at a scan rate of 10 mV s −1 and 1693.2 F g −1 at a current density of 1 A g −1 as well as long‐term cycling stability and high energy density (66.2 W h kg −1 at a power density of 0.25 kW kg −1 ), which are better than that of the individual component of Co 3 O 4 nanoneedles and MnO 2 nanosheets, are obtained. The Co 3 O 4 @MnO 2 NAs are also tested as anode material for LIBs for the first time, which presents an improved performance with high reversible capacity of 1060 mA h g −1 at a rate of 120 mA g −1 , good cycling stability, and rate capability.

Abstract The excessive enrichment of nitrate in the environment can be converted into ammonia (NH 3 ) through electrochemical processes, offering significant implications for modern agriculture and the potential to reduce the burden of the Haber–Bosch (HB) process while achieving environmentally friendly NH 3 production. Emerging research on electrocatalytic nitrate reduction (eNitRR) to NH 3 has gained considerable momentum in recent years for efficient NH 3 synthesis. However, existing reviews on nitrate reduction have primarily focused on limited aspects, often lacking a comprehensive summary of catalysts, reaction systems, reaction mechanisms, and detection methods employed in nitrate reduction. This review aims to provide a timely and comprehensive analysis of the eNitRR field by integrating existing research progress and identifying current challenges. This review offers a comprehensive overview of the research progress achieved using various materials in electrochemical nitrate reduction, elucidates the underlying theoretical mechanism behind eNitRR, and discusses effective strategies based on numerous case studies to enhance the electrochemical reduction from NO 3 ˗ to NH 3 . Finally, this review discusses challenges and development prospects in the eNitRR field with an aim to guide design and development of large‐scale sustainable nitrate reduction electrocatalysts.