Considering the rapid increase of CO2 emission, especially from power plants, there is a constant need for materials which can effectively eliminate post-combustion CO2 (the main component: CO2/N2 = 15/85). Here, we show the design and synthesis of a Cu(II) metal-organic framework (FJI-H14) with a high density of active sites, which displays unusual acid and base stability and high volumetric uptake (171 cm3 cm−3) of CO2 under ambient conditions (298 K, 1 atm), making it a potential adsorbing agent for post-combustion CO2. Moreover, CO2 from simulated post-combustion flue gas can be smoothly converted into corresponding cyclic carbonates by the FJI-H14 catalyst. Such high CO2 adsorption capacity and moderate catalytic activity may result from the synergistic effect of multiple active sites.

Recently, flexible capacitive pressure sensors have received significant attention in the field of wearable electronics. The high sensitivity over a wide linear range combined with long-term durability is a critical requirement for the fabrication of reliable pressure sensors for versatile applications. Herein, we propose a special approach to enhance the sensitivity and linearity range of a capacitive pressure sensor by fabricating a hybrid ionic nanofibrous membrane as a sensing layer composed of Ti3C2T x MXene and an ionic salt of lithium sulfonamides in a poly­(vinyl alcohol) elastomer matrix. The reversible ion pumping triggered by a hydrogen bond in the hybrid sensing layer leads to high sensitivities of 5.5 and 1.5 kPa–1 in the wide linear ranges of 0–30 and 30–250 kPa, respectively, and a fast response time of 70.4 ms. In addition, the fabricated sensor exhibits a minimum detection limit of 2 Pa and high durability over 20 000 continuous cycles even under a high pressure of 45 kPa. These results indicate that the proposed sensor can be potentially used in mobile medical monitoring devices and next-generation artificial e-skin.

Defect and interface engineering are recognized as effective strategies to regulate electronic structure and improve activity of metal sulfide. However, the practical application of sulfide is restricted by their low conductivity and rapid decline in activity derived from large volume fluctuation during electrocatalysis process. More importantly, the determination of exact active site of sulfide is complicated due to the inevitable electrochemical reconstruction. Herein, ZnS nanoparticles with Zn defect are anchored onto the surface of NiCo2S4 nanosheet to construct NiCo2S4/ZnS hybrids, which exhibit outstanding oxygen evolution performance with an ultralow overpotential of 140 mV. The anchoring of defective ZnS nanoparticles inhibit the volume expansion of NiCo2S4 nanosheet during the cycling process. Density‐functional theory reveals that the build‐in interfacial potential and Zn defect can facilitate the thermodynamic formation of *O to *OOH, thus improve their intrinsic activity.

Vacancy defects of catalysts have been extensively studied and proven to be beneficial to various electrocatalytic reactions. Herein, an ultra‐stable three‐dimensional PtCu nanowire network (NNW) with ultrafine size, self‐supporting rigid structure, and Cu vacancy defects has been developed. The vacancy defect‐rich PtCu NNW exhibits an outstanding performance for the oxygen reduction reaction (ORR), with a mass activity 14.1 times higher than for the commercial Pt/C catalyst (20 %.wt, JM), which is currently the best performance. The mass activity of the PtCu NNW for methanol oxidation reaction (MOR) is 17.8 times higher than for the commercial Pt/C catalyst. Density‐functional theory (DFT) calculations indicate that the introduction of Cu vacancies enhances the adsorption capacity of Pt atoms to the HO* intermediate and simultaneously weakens the adsorption for the O* intermediate. This work presents a facile strategy to assemble efficient electrocatalysts with abundant vacancy defects, at the same time, provides an insight into the ORR mechanism in acidic solution.

No abstract

miniaturizing the portable energy harvesting devices that can replace the conventional batteries to realize a self-powered system by scavenging energy from ambient sources such as human biomechanical energy, [1,2] blue energy, [3-6] solar, [7,8] stray magnetic fields, [9,10] and wind energy. [11-14] The ambient environment has abundant sources of mechanical energy that is being wasted but has huge potential to be converted into useful electric energy. The scavenging of wasted biomechanical energy during human locomotion can be an ideal approach toward a sustainable power supply for wearable electronics and health-care monitoring sensors. [15,16] This will help to increase the run time of the electronic device and sensors such as continuous glucose monitoring sensors, pacemakers, blood pressure monitoring systems, and so on. Also, these portable biomechanical energy harvesters can provide power supply during hiking, trekking, camping, traveling, mountaineering, and so forth. Likewise, water wave energy is also easily available in the oceans, seas, and rivers which can be converted into useful electrical energy. Besides these, automobile vibration is another source of electrical energy. These days, automobiles use a huge number of sensors and monitoring systems which drains a large amount of energy from the automobile battery. Harvesting automotive vibration energy and use for powering those sensors can be game changing toward a self-powered system. Therefore, all these mechanical energies are the potential source of power supply for the increasing number of wearable electronic devices, internet of things (IoT) devices, and sensors. Different methodologies have been demonstrated to harvest mechanical energy such as electromagnetic (EMG), [17,18] triboelectric (TENG), [19-21] and piezoelectric (PENG) effect. [22,23] Each mechanism has its own characteristics such as EMG has comparatively high output current and low output voltage which is exactly opposite to TENG. Moreover, to optimize the output of EMG many advanced designs, [17,24,25] frequency upconversion mechanisms, [26,27] and flux enhancement methods have been reported. [28] To improve the TENG performance, Realization of self-charging, miniaturized, portable, high output, and sustainable energy harvesting devices with wide application areas and good storage under a realistic environment remains a challenge. Herein, a universal selfchargeable power module (USPM) is presented that can efficiently harvest human bio-mechanical energy, ocean wave blue energy, and automobile vibration energy. By implementing a multiple spring-based mechanical coupling design, the hybrid electromagnetic-triboelectric generator shows high performance despite miniaturization under very low acceleration (≤1 g) and low frequency (≤6 Hz) vibration. The electromagnetic performance is further optimized by using a soft magnetic material-based flux concentrator while electrospun nanofibers enhance the triboelectric performance. The USPM is a compactly designed device including a power manag...

A novel sulfur-functionalized metal–organic framework FJI-H12 has been developed, which can completely and selectively remove Hg(ii) from water with high saturation, adsorption and distribution.

A metal–organic framework with high adsorption and selectivity for reversible uptake of Cd(ii) was developed. Both fast detection of Cd(ii) at low concentration and in situ reconstruction of the used MOF were successfully achieved.