Metal-Organic Framework Wears a Protective Cover for Improved Stability.

Metal-organic frameworks (MOFs) with an ordered channel and porosity show great promise for a myriad of purposes. Unfortunately, the coordination bond of metal ions and organic ligands easily weakens in unfavorable environments, which poses a key problem in expanding the application of MOFs. Herein, we report a general and efficient strategy to enhance the stability and preserve the porosity of MOFs by coating them with reduced graphene oxide (rGO). The prepared hybrid material consisted of MOFs and rGO, as the core and the protective shell, respectively. It is worth noting that the obtained MOFs@rGO composite material maintained a well-defined crystal structure and showed good catalytic activity as well as enhanced stability. Notably, this novel and general method of coating MOFs with a thin protective rGO shell will broaden the application fields of MOFs and open up a new avenue for the research of MOFs.

Wearable Leather-Based Electronics for Respiration Monitoring.

This article presents a leather-based respiration sensor based on the ionic conductivity change of leather, caused by humidity variation during breathing. Leather was applied as a flexible substrate due to its biocompatibility, hydroscopicity, porosity, and ionic conductivity. Printing method was employed to fabricate the sensor, which could convert human respiration to electrical signals. By combining the leather with silver nanowires (AgNWs), data about human respiration rate, respiration depth, and respiration pattern can be acquired easily through a noninvasive way. Such sensor could work tens of hours consecutively due to the unique properties of leather.

Repurposed Leather with Sensing Capabilities for Multifunctional Electronic Skin.

Electronic skin (e-skin), an important part toward the realization of artificial intelligence, has been developing through comprehending, mimicking, and eventually outperforming skin in some aspects. Most of the e-skin substrates are flexible polymers, such as polydimethylsiloxane (PDMS). Although PDMS was found to be biocompatible, it is not suitable for long-time wearing due to its air impermeability. This study reports a simple and designable leather based e-skin by merging the natural sophisticated structure and wearing comfort of leather with the multifunctional properties of nanomaterials. The leather based e-skin could make leather, "the dead skin," repurposed for its sensing capabilities. This e-skin can be applied in flexible pressure sensors, displays, user-interactive devices, etc. It provides a new class of materials for the development of multifunctional e-skin to mimic or even outshine the functions of real skin.

Metal-organic framework derived leaf-like CoSNC nanocomposites for supercapacitor electrodes.

The designed construction of micro-/nano-structures and multi-composites on electrodes showed a promising prospect to improve electrochemical properties in supercapacitors. Herein, a facile carbonizing strategy was adopted for fabricating leaf-like CoSNC nanocomposites, which possess both the sheet structure and multi-composites of well-dispersed CoS2 nanoparticles in N-doped carbon frameworks. First, the leaf-like nanocomposites with high aspect ratios effectively shortened the ion/electron transmission paths and exposed more faradaic redox sites. Second, the N-doped carbon frameworks could stabilize the electrode structure during charge/discharge processes. Third, the well-dispersed CoS2 nanoparticles could also enhance the electrochemical kinetics. Hence, leaf-like CoSNC nanocomposites as electrode materials exhibited high specific capacitance, good rate capacity and cycling stability.