Nanoclay Modulates Cation Occupancy in Manganese Ferrite for Catalytic Antibacterial Treatment

Abstract

Controllable preparation is the current frontier in the field of inorganic nanomaterial-based artificial enzymes (nanozymes). For ferrites, the factors affecting cation occupancy are very complex, making the modulation of cation occupancy extremely challenging. Herein, we report a new strategy to modulate the cation occupancy of manganese ferrite (MFO) based on the structural properties of nanoclay (i.e., montmorillonite K10). It demonstrates that montmorillonite K10 mainly changes the valence state and occupancy of manganese ions in manganese ferrite and not iron ions. K10 increases the proportion of Mn (II) in manganese ferrite and causes more manganese ions to migrate to the tetrahedral sites. As expected, the prepared new inorganic compound possesses excellent enzyme-like catalytic activities and antibacterial functional properties, which are attributed to Mn (II) accelerating Fe (III) reduction and hydroxyl radical formation. Furthermore, steady-state kinetic assays are used to study the reaction mechanism in detail. In vitro and in vivo antibacterial experiments show that the synthesized inorganic compounds exhibit satisfactory disinfection and wound skin recovery efficiencies. This work emphasizes the controllable preparation of new inorganic compounds with biomimetic activity and provides novel insight into the biological effects of inorganic nanomaterials.

Breaking through the pH Limitation of Fe1–xS Nanozymes Using Component-Modulated Coupled Nanoclay

“…MMT-based nanozymes were synthesized, including Co 3 O 4 -MMT, CeO 2 -MMT, and V 2 O 5 -MMT. − These results suggest that MMT has great potential in enhancing the enzyme-like activity of nanozymes. Our group demonstrated that MMT could modulate the edge surface state of MoS 2 and enhance the catalytic performance of MoS 2 /MMT composites; the surface properties of MMT can modulate the crystal structure of manganese ferrite nanozymes, increase the proportion of Mn ions in the ferrite, and cause more Mn ions to migrate to the tetrahedral sites, thus significantly enhancing the enzyme-like activity of the composites . Inspired by this, we wonder if a MMT-based interfacial modulation strategy enables us to modulate the structure of iron sulfides and enhance their enzyme-like activity in neutral pH, and this is another trigger for our study.…”

Understanding the Nanoscale Affinity between Dissolved Organic Matter and Noncrystalline Mineral with the Implication for Water Treatment

“…Hence, the effectiveness of ion exchange in Mt increases the Ca amount, which has the potential to form calcium-containing minerals . During CaP precipitation, both Mt and DOM can strongly influence the earliest nucleation and subsequent CaP particle aggregation in the soil. , In addition, the unique properties of clay minerals, including large surface area, tunable size, biocompatibility, low cost, and controlled structure, make them good candidates for pollutant treatment in aquatic environment. – The effect of DOM adsorption on the environmental behavior and function of the clay based noncrystalline minerals as well as the favorable adsorption sites (ion exchange sites and surface adsorption sites) of HA are crucial for the design of adsorbent materials.…”

“…Natural clay particles have hydrophilic properties, a high capacity for adsorption, and a specific surface area and are harmless to humans. 7,8 In soil environments, the deposition process of DOM is mainly adsorption on the surface of soil minerals, which have many physical and chemical reaction sites for organic groups, especially clay-sized particles. 9−11 Spatially complex and active environs within the soil minerals' porous structure support the high adsorption of DOM.…”

Emerging Phosphate-Functionalized Co3O4/Kaolinite Composites for Enhanced Activation of Peroxymonosulfate

“…Interestingly, nanoclay materials have attracted considerable and promising attention, owing to the wide availability of this natural mineral around the world, their low cost, and the availability of plenty of surface hydroxyl groups, making them appropriate for support and functional materials. − As is well known, kaolinite (Kaol) with the chemical composition Al 2 Si 2 O 5 (OH) 4 is a typical 1:1 layered structure formed by stacking the octahedral (Al–O) and tetrahedral (Si–O) structures. − Our previous study has also indicated that kaolinite surfaces with rich hydroxyl groups could hinder the surface dehydration process of Co 3 O 4 nanoparticles and thus can induce the formation of oxygen vacancies in the Co 3 O 4 catalyst, which facilitate the electron transfer for PMS activation . Taking into consideration the 2D structure of the nanoclay mineral, assembling transition-metal oxides on kaolinite is thus effective in boosting the Fenton-like catalytic processes. , Most importantly, it would be meaningful to explore the role of hydroxyl groups on the surface of kaolinite in tuning coordination sites, which is highly expected to provide further insight into the mechanism of PMS activation …”