Lei Peng,Hao Li,Yi Zhang,Jiao Su,Ping Yu,Yunbai Luo
Oil spills are a serious threat to environment and marine ecosystems; hence, it is urgent to identify an economic and efficient countermeasure to deal with them. In this work, a kind of superhydrophobic 3D porous material is fabricated for oil spill cleanup. Oil is selectively absorbed in the material at first, and then sucked by a pump. The superhydrophobicity and factors influencing oil collection rates are studied. The results show that the water contact-angle is 155°, and the oil collection rate can reach 2.8 g s−1 under appropriate conditions. A plurality of these materials can be connected to a similar pump simultaneously, forming a network for oil cleanup. As the 3D material together with the pumping method can realize a continuous cleanup with high efficiency, it can be thought of as a promising candidate for oil spill cleanup applications.
Electrocatalytic nitrate (NO3−) reduction to ammonia (NH3) (NRA) is of great significance for solving the problem of urgent NO3− pollution in the environment and opening up a new route to synthesize NH3. However, NRA is limited by its multi-electron/proton transfer process and the NRA process relies heavily on atomic H* produced by H2O splitting, undergirding the necessity for effective NRA catalysts. Herein, three-dimensional (3D) porous phosphorus (P)-doped Cu–Ni alloy materials are constructed through a one-step electrodeposition synthesis. 3D porous materials modulate hydrophilicity and enrich active sites. The Cu d-band center can be tuned through Ni alloying to modify the adsorption energies of intermediates such as *NO3−, *NO2−, and *NH2. The hydrogenation evolution capacity of P promotes the hydrogenation process in the atomic H* path and effectively accelerates the NRA reaction rate. Density functional theory (DFT) calculations demonstrate that the charge transfer between the negatively charged Pδ− and the positively charged Niδ+ and Cuδ+ assists in generating more atomic H* for coupling with reaction intermediates, showing an enhanced catalytic activity at low overpotential. The optimal sample exhibits an exceptional NRA performance with an ammonia yield rate of 848.1 μmol h−1 cm−2 and a faradaic efficiency of 96.1%. This work provides a strategy for creating effective NRA catalysts through enhancing the atomic H* reduction strategy.
3D Porous MnO x /rGO hydrogel (3DP MnO x /rGO hydrogel) as cathode material for aqueous zinc ion batteries (AZIBs) is synthesized by polyvinyl alcohol (PVA), nanowires of MnO x (NW MnO x ) and reduced graphene oxide (rGO) via repeated freeze-thaw method, which has a high flexibility and puncture resistance. The 3D self-supporting hydrogel presented complex 3D cross-linking system and excellent flexibility through hydrogen bonding and reinforcement of inorganic nano wires. The electrochemical and mechanical properties of the 3DP MnO x /rGO hydrogel are optimized by adjusting the respective percentages of NW MnO x (30%), rGO (5%), PVA (25%), and H 2 O (40%) in the total mass. The flexible hydrogel cathode exhibits a high capacity of 297.6 mA h g −1 and good cyclic stability after 500 cycles at 1 A g −1 . Finite element method confirms that the hydrogel material can alleviate the stress distribution caused by zincification process. The soft-packaged AZIBs, which utilize 3DP MnO x /rGO hydrogel as the cathode and Zn foil as the anode, exhibit excellent cycling performance (152.2 mA h g −1 at 1 A g −1 after 500 cycles under an angle of 180°) and provide a stable power supply across different bending angles.
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