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Electrified membranes (EMs) have the potential to address inherent limitations of conventional membrane technologies. Recent studies have demonstrated that EMs exhibit enhanced functions beyond separation. Electrification could enhance the performance and sustainability of membrane technologies and stimulate new applications in water and wastewater treatment. Herein, we first describe EM materials, synthesis methods, electrofiltration modules, and operating modes. Next, we highlight applications of EMs in water decontamination, purification, and disinfection. Additionally, we discuss state-of-the-art electrification methods for controlling membrane organic fouling, biofouling, and inorganic scaling. We also evaluate the energy consumption of EMs for water treatment and fouling control. We conclude by discussing the challenges for improving the stability and practicality of EMs and by proposing pathways for future research and development. On the basis of our discussion, we suggest that EMs may be viable for ultrafiltration and microfiltration but not for salt-rejecting reverse osmosis and nanofiltration applications. Further, we find that EMs are promising for decontamination and organic fouling control, and these systems could be deployed for fit-for-purpose distributed treatment applications.

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Ammonia synthesis by plasma catalysis has emerged as an alternative process for decoupling nitrogen fixation from fossil fuels. Plasma activation can potentially circumvent the limitations of conventional thermocatalytic ammonia synthesis; however, the contribution of different reaction mechanisms to the production of ammonia at the catalyst surface remains unclear. Here, we identify the reaction intermediates adsorbed on γ-Al 2 O 3 -supported Ni and Fe catalysts during plasma-activated ammonia synthesis under various temperatures and reactor configurations using FTIR spectroscopy, steady-state flow reactor experiments, and computational kinetic modeling. Ammonia yield can be influenced by plasma-derived intermediates and their interactions with catalyst surfaces, which lead to different reaction pathways: Ni/γ-Al 2 O 3 enhances plasma-promoted NH 3 production and favors surface-adsorbed NH x species, while Fe/γ-Al 2 O 3 shows the presence of N 2 H y and a lower overall concentration of N-containing adsorbates. Plasma−catalyst interactions are probed to reveal that elevated temperature and plasma irradiation of the surfaces promote NH 3 desorption. The direct evidence of catalytic surface reactions occurring during a plasma-activated process provides mechanistic insight into plasma-activated ammonia synthesis.

The co-conversion of CO2 and CH4 into oxygenates with nonthermal plasma is attracting considerable interest, principally because this approach can overcome thermodynamic limitations and enables operation under mild conditions. However, plasma must be coupled with appropriate catalysts in order to achieve satisfactory oxygenate selectivities. In this article, the mechanisms underlying plasma-catalytic CO2 + CH4 conversion to three different types of oxygenates (CH3OH, HCHO, and CH3COOH) are discussed along the scales of reaction time (ns to ms) and dimension (nm to mm). Particular emphasis is given to the synergy between plasma-phase and surface reactions. In addition, typical materials (both catalytic and noncatalytic) and experimental setups that can affect the selectivities of oxygenated products are also highlighted.