A new acoustomicrofluidic method for synthesizing copper-based metal–organic frameworks is shown to yield novel large aspect ratio elongated crystal morphologies with high active metal site density on their surfaces, leading to enhanced conductivity.
Two-dimensional (2D) graphitic materials are often incorporated with metal–organic frameworks (MOFs) to compensate for the poor electrical conductivity of the latter, particularly if they are to be used for electrochemical...
Despite its appeal of green H 2 production using energy from renewable sources, water electrolysis currently only accounts for a small percentage of global H 2 production due to the need for expensive electrocatalysts to compensate for Ohmic losses associated with the kinetic overpotential of the system. [4][5][6] At present, H 2 production via electrolysis is predominantly carried out in strong acidic/alkaline electrolytes using state-of-the-art platinum group metal (PGM) electrocatalysts, which enables hydrogen evolution reactions (HER) to be conducted at the lowest onset potential, albeit at practically insurmountable industrial costs due to the metal's scarcity. [7,8] To attain industrially-relevant current densities (200-500 mA cm −2 ), an overpotential between 1.8 and 2.5 V is typically required. [9] At these levels though, acidic electrolytes-while providing an abundant source of protons (H + ) and hydronium (H 3 O + ) ions-produce acid fog under high temperatures that can corrode the electrolyzer and contaminate the product. [10] Alkaline electrolysis, on the other hand, is commonly plagued by unstable electrocatalysts and the need for expensive pH-tolerant membranes. [11][12][13] It is therefore desirable to carry out electrolysis in neutral or near-neutral electrolytes (pH 5-9) with non-PGM electrocatalysts. [14] The HER rate under these conditions is, nevertheless, significantly lower than those for electrolytes with extreme pH levels. In addition to diffusion limitations, this is due to the rapid consumption of H 3 O + , which creates a bottleneck that limits the extent of reaction until higher overpotentials are able to drive H 2 O reduction. [10,[15][16][17] Even with the best electrodes (i.e., PGMs), H 2 production is several orders of magnitude lower under neutral conditions, [7] such that the overpotential required to reach a current density of −4 mA cm −2 exceeds 0.25 V in a 0.1 M KClO 4 electrolyte compared to as little as 30 mV in 0.5 M H 2 SO 4 . [18,19] Similarly poor performance is obtained with the use of nickel-based electrocatalysts, which are generally favored for alkaline conditions, given their affinity for OH − adsorption. [20] To circumvent these limitations, novel electrocatalysts have been designed, in which the electrode is doped to tailor its catalytic sites for both H* and OH* adsorption to complement the electrolytic conditions, [21][22][23] or through the introduction of complex architectures that facilitate more favorable local pH environments, [24] although these strategies A novel strategy utilizing high-frequency (10 MHz) hybrid sound waves to dramatically enhance hydrogen evolution reactions (HER) in notoriously difficult neutral electrolytes by modifying their network coordination state is presented. Herein, the practical limitations associated with existing electrolyzer technology is addressed, including the need for highly corrosive electrolytes and expensive electrocatalysts, by redefining conceptually-poor hydrogen electrocatalysts in neutral electrolytes. The impro...
Metal−organic frameworks (MOFs) have recently been shown to be effective antimicrobial agents, particularly if they comprise pathogenicidal metal ions. Nevertheless, the accessibility of these active metal sites to the pathogen, and hence the MOFs' antimicrobial activity itself, is often poor since the metal nodes are usually embedded deep within its three-dimensional (3D) structure. We show that a unique copper-based (copper(II)-benzene-1,3,5-tricarboxylate) MOF, whose quasi-two-dimensional (quasi-2D) swordlike structure facilitates exposure of the metal ions along its surface, exhibits enhanced antimicrobial properties against three representative plant pathogens: a bacterium (Pseudomonas syringae), a fungus (Fusarium solani), and a virus (Odontoglossum ringspot virus (ORSV)). Such superior antimicrobial activity results in low minimum inhibitory concentrations (MICs)half that of a commercial pesticide and an eighth of its conventional 3D cubic MOF counterpart (HKUST-1)and hence low phytotoxicity, which can be attributed to the accessibility of the surface copper sites to the pathogen, thereby facilitating their adhesion and physical contact with the MOF. Additionally, we observed that orchids treated with the quasi-2D MOF showed negligible phytotoxicity and 80% decreased viral load. This work constitutes the first study to demonstrate the antimicrobial properties of this novel MOF against bacterial, fungal, and viral plant pathogens, and the first chemical control of ORSV.
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.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.