An ethylenediamine-grafted Y zeolite effectively adsorbs CO₂from a wet flue gas and it is highly regenerable through a temperature swing adsorption (TSA) process.

Zinc-air batteries (ZABs) are promising electrochemical energy storages, but inefficient oxygen reduction reaction (ORR) during discharging and oxygen evolution reaction (OER) during charging at their cathodes impede achieving high energy density and stable cycling. We report a serrated leaf-like nitrogen-doped copper sulfide (N-CuS) cathode with conductive N 2p-S 3p hybridized orbitals, oxygen-transporting mesopores, and about fivefold larger surface area than Cu. A ZAB with the N-CuS cathode exhibits a 788 mAh g^-1 capacity (96% of theoretical) and a hitherto highest energy density of 916.0 Wh kg^-1, surpassing one with the state-of-the-art Pt/C+RuO₂ cathode (712.43 mAh g^-1 and 874 Wh kg^-1). Density functional theory calculations elucidate that O═O bond dissociation is 0.97 eV more favorable on N-CuS than CuS. Subsequently, protonation of surface-adsorbed *O to *OH occurs via dissociate (0.55 V), non-spit associate (1.05 V), and split associate (1.05 V) pathways, with *OH then desorbing as OH^-. Under anaerobic conditions, copper oxide transitions from CuO to Cu₂O (1.05 V) and eventually to Cu (0.75 V) releasing oxygen to sustain ORR. Additionally, a ZAB with the N-CuS cathode achieves about threefold longer cyclability than one with the Pt/C+IrO₂ cathode, and about six-fold longer cyclability than one with the Pt/C+RuO₂ cathode.

Coastal inundation caused by seawater overtopping/overflow due to sea level rise and extreme coastal disaster events poses a significant threat to coastal groundwater resources. Seawater intrusion into coastal aquifers accelerates salinization, disrupting the natural freshwater balance and limiting sustainable water supply for drinking and agriculture. This study uses numerical simulations based on a porous body model to investigate the vertical seawater intrusion process triggered by coastal inundation. The inundation height, distance, and hydraulic gradient effects on salinization and recovery dynamics in coastal aquifers were analyzed. The results indicate that longer inundation distances cause more extensive salinization, whereas higher inundation heights accelerate vertical intrusion. Additionally, lower hydraulic gradients lead to prolonged retention of saline water, delaying recovery. In contrast, higher hydraulic gradients facilitate rapid discharge of intruded seawater, accelerating salinization recovery. The recovery process follows a logarithmic trend, initially rapid but slowing. These findings emphasize the importance of understanding the interplay between coastal inundation conditions and groundwater flow dynamics to effectively manage and protect coastal freshwater resources.

Zinc-air batteries (ZABs) are attractive electrochemical energy storages for advanced applications across various fields, but their performance in terms of energy density and stability is tied to the efficiency and durability of a bifunctional cathode structure that governs oxygen evolution reaction (OER) during discharging and oxygen reduction reaction (ORR) during charging. Here, we present a bifunctional cathode based on a NiFe core encapsulated by a porous pyridinic N-doped graphitic carbon shell (NiFe/NC), which enables both ORR/OER for high performance in ZABs. The NC shell is rich in pyridinic/graphitic N sites and features ion-accessible pores, while the NiFe alloy core contains high-valent Ni²⁺/³⁺ and Fe²⁺/³⁺ sites. Pyridinic N sites aid in the adsorption of reduced oxygen species while suppressing H₂O₂ formation, graphitic N-doped sites promote electron transport, and rich pores accelerate ion transport for efficient ORR. Besides, nucleophilic Ni²⁺/³⁺ and Fe²⁺/³⁺ sites and loose NiFe packing promote OER by facilitating electron and ion transport. Moreover, the ZAB with the NiFe/NC cathode achieves a notable energy density of 879 Wh kg^-1 and excellent stability over 1000 cycles without significant voltage degradation, outperforming the Pt/C+RuO₂-based ZAB that delivers an energy density of 844 Wh kg^-1 and degrades over 181 cycles.

Minimizing the use of iridium (Ir) in proton exchange membrane water electrolyzers (PEMWEs) is essential for hydrogen production without carbon emission. Herein, layered monoclinic iridium nickel oxide (IrNiOx) platelets were synthesized using the molten salt method and used for the oxygen evolution reaction (OER) in a PEMWE. The IrNiOx hexagonal platelets consist of the edge-sharing octahedral framework, in which Ni atoms replace Ir sites in the crystalline lattice. Thin IrNiOx platelets exhibited high OER activity with suppressed Ni dissolution from the bulk lattice in acidic media. When the platelets were applied in a membrane electrode assembly (MEA), they presented improved interconnectivity in the catalyst layer, facilitating electron transfer. Even at a low Ir loading of 0.2 mgIr cm–2, the platelets presented good performance with an initial cell voltage of 1.70 V at a current density of 1 A cm–2. Despite the use of a Ti porous transport layer (PTL) without Pt coating, the PEMWE operated stably for 150 h, exceeding the performance achievable by commercial Ir oxide and rutile IrO2. When a Pt-coated Ti PTL was used, the PEMWE could be operated stably for 500 h. Incorporating earth-abundant transition metals into the Ir oxide lattice can be an effective way to minimize the use of Ir in PEMWEs.