Electrochemical synthesis of NH3 is a carbon-free alternative to the traditional Haber-Bosch process. The challenge with nitrogen reduction reaction (NRR) to NH3 is cleavage of the inert N≡N triple bond of nitrogen gas. Obtaining NH3 from environmental pollutants, such as nitrates or nitrites, is a more practical route than NRR. However, reduction of nitrates or nitrites to ammonia is currently hampered by modest Faradaic efficiencies, typically below 10 %. Here, we report a novel heterogeneous catalyst based on iron (Fe) single-atoms supported on two-dimensional MoS2 (Fe-MoS2) for the nitrate reduction reaction (NO3RR). We have found that Fe-MoS2 exhibits remarkable performance with a maximum Faradaic efficiency of 98 % for NO3RR to NH3 at an overpotential of -0.48 V vs. the reversible hydrogen electrode (RHE) as confirmed by our isotopic nuclear magnetic resonance (NMR) analyses. Density function theory (DFT) calculations reveal that the enhanced selectivity for the production of NH3 from single Fe atoms supported on MoS2 is attributed to a reduced energy barrier of 0.38 eV associated with de-oxidation of *NO to *N -the usual potential limiting step in NO3RR. We assembled our catalyst in a two-electrode electrolyzer coupled to an InGaP/GaAs/Ge triple-junction solar cell to demonstrate a solar-to-ammonia (STA) conversion efficiency of 3.4 % and a yield rate of 0.03 mmol h -1 cm -2 equivalent to 510 µg h -1 cm -2 . Our results open new avenues for design of single-atom catalysts (SAC) for the realization of solar-driven ammonia production.
For the practical applications of wearable electronic skin (e‐skin), the multifunctional, self‐powered, biodegradable, biocompatible, and breathable materials are needed to be assessed and tailored simultaneously. Integration of these features in flexible e‐skin is highly desirable; however, it is challenging to construct an e‐skin to meet the requirements of practical applications. Herein, a bio‐inspired multifunctional e‐skin with a multilayer nanostructure based on spider web and ant tentacle is constructed, which can collect biological energy through a triboelectric nanogenerator for the simultaneous detection of pressure, humidity, and temperature. Owing to the poly(vinyl alcohol)/poly(vinylidene fluoride) nanofibers spider web structure, internal bead‐chain structure, and the collagen aggregate nanofibers based positive friction material, e‐skin exhibits the highest pressure sensitivity (0.48 V kPa−1) and high detection range (0–135 kPa). Synchronously, the nanofibers imitating the antennae of ants provide e‐skin with short response and recovery time (16 and 25 s, respectively) to a wide humidity range (25–85% RH). The e‐skin is demonstrated to exhibit temperature coefficient of resistance (TCR = 0.0075 °C−1) in a range of the surrounding temperature (27–55 °C). Moreover, the natural collagen aggregate and the all‐nanofibers structure ensure the biodegradability, biocompatibility, and breathability of the e‐skin, showing great promise for practicability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.