RESUMEN
The rapid growth of Internet of Things (IoT) in recent years has increased demand for various sensors to collect a wide range of data. Among various sensors, the demand for force sensors that can recognize physical phenomena in 3D space has notably increased. Recent research has focused on developing energy harvesting methods for sensors to address their maintenance problems. Triboelectric nanogenerator (TENG) based force sensors are a promising solution for converting external motion into electrical signals. However, conventional TENG-based force sensors that use the signal peak can negatively affect data accuracy. In this study, a Scott-Russell linkage-inspired TENG (SRI-TENG) is developed. The SRI-TENG has completely separate signal generation and measurement sections, and the number of peaks in the electrical output is measured to prevent disturbing output signals. In addition, the lubricant liquid enhances durability, enabling stable force signal measurements for 270 000 cycles. The SRI system demonstrates consistent peak counts and high accuracy across different contacting surfaces, indicating that it can function as a contact material-independent self-powered force sensor. Furthermore, using a deep learning method, it is demonstrated that it can function as a multimodal sensor by realizing the tactile properties of various materials.
RESUMEN
We studied the electrochemical synthesis of NH3 on Fe-CuS/C catalysts in an alkaline aqueous solution under ambient conditions. The metal chalcogenide catalyst is active in the nitrogen reduction reaction (NRR) for approximately 45 min with an NH3 production yield of 16 µg h-1 cm-2 at -0.4 VRHE, while it decomposes to CuO. The rapid degradation of the catalyst hinders the precise investigation of the NH3 production activity in longer time measurements. Herein, the electrochemical NH3 production rate is enhanced with increased overpotentials when the degradation effect is mitigated in the measurement, which was difficult to observe in the NRR reports. In the Tafel analysis, the exchange current density, heterogeneous rate constant, and transfer coefficient of the Fe-CuS/C catalyst on the NRR were estimated. When the electrode degradation is mitigated, one of the best NH3 production activities among the reported metal sulfide electrochemical NRR catalysts is obtained, which is 42 µg h-1 cm-2 at -0.6 VRHE.
RESUMEN
Single-atom catalysts are heterogeneous catalysts with atomistically dispersed atoms acting as a catalytically active center, and have recently attracted much attention owing to the minimal use of noble metals. However, a scalable and inexpensive support that can stably anchor isolated atoms remains a challenge due to high surface energy. Here, copper-halide polymer nanowires with sub-nanometer pores are proposed as a versatile support for single-atom catalysts. The synthesis of the nanowires is straightforward and completed in a few minutes. Well-defined sub-nanometer pores and a large free volume of the nanowires are advantageous over any other support material. The nanowires can anchor various atomistically dispersed metal atoms into the sub-nanometer pores up to ≈3 at% via a simple solution process, and this value is at least twice as big as previously reported data. The hydrogen evolution reaction activity of -18.0 A mgPt -1 at -0.2 V overpotential shows its potential for single-atom catalysts support.