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The Ag nanoparticles demonstrate potent bacteria eradication capabilities; however, their tendency to aggregate in aqueous solutions compromises the antibacterial efficacy. Furthermore, the Ag nanoparticles employed in sewage treatment are challenging to recycle, resulting in environmental pollution and resource wastage. Herein, the Ag-core Fe3O4-shell structured particles (Ag@Fe3O4) are synthesized by leveraging the reduction potential difference between Ag+/Ag0 and Fe3+/Fe2+ through a one-step polyol reduction process. The Fe3O4 shell in the Ag@Fe3O4 composite not only effectively inhibits the agglomeration of Ag, but also enhances the penetration capability of the composite into biofilms, thereby enabling Ag@Fe3O4 to possess remarkable antibacterial efficacy against Escherichia coli (E. coli). The Ag@Fe3O4 demonstrates nearly 100 % inhibition of E. coli at a concentration of 0.24 mg mL−1 (with an Ag content of 0.042 mg mL−1) while still maintaining antibacterial effectiveness of 74.6 % even after undergoing reutilization for 10 cycles. Meanwhile, due to the excellent electron conductivity of Ag and the effective adsorption capability of Fe3O4 shell towards organic dyes, Ag@Fe3O4 facilitates rapid electron transfer to organic dyes and further lead to their reduction and degradation in the presence of NaBH4. The Ag@Fe3O4 can catalytically degrade various organic dyes (including Rhodamine B, Rhodamine 6G, and Methylene blue) within only 15 min, while achieving an impressive degradation efficiency exceeding 90.9 % after 6 cycles of reutilization. The cost-effectiveness (approximately $0.17 per gram), facile magnetic recovery, along with the superior antibacterial and dye-degradation performance showcase the significant potential of Ag@Fe3O4 for medical applications and sewage treatment.

• The BiFeO 3 /X-rGA composite was prepared by doping with heteroatoms. • A synergy system of adsorption and catalytic degradation system was constructed. • Heteroatom doping enhances graphene adsorption and catalytic degradation activity. • The coupled system showed good removal of coking wastewater and organic pollutants. In this paper, a multifield coupled system of synergistic adsorption and photo-Fenton degradation was constructed, and BiFeO 3 -modified nonmetallic element-doped graphene aerogel composites (BiFeO 3 /X-rGA) were prepared to realize the advanced treatment of phenol and coking wastewater by utilizing consistent adsorption and catalytic degradation sites. Nonmetallic element-doped graphene formed more defective active sites and changed the planar carbon layer structure, which enhanced the adsorption performance of pollutants on the basis of graphene face adsorption and π-π adsorption. Moreover, element doping also modulated the localized electronic structure of graphene and promoted carrier separation, which in turn enhanced the photo-Fenton degradation activity. The phenol degradation rate constant of BiFeO 3 /P-rGA was 3.29 times greater than that of BiFeO 3 /rGA, and the removal efficiency in coking wastewater was also greatly improved. In coupled systems, hydroxyl radicals are the predominant active species, and the mechanism by which nonmetallic modifications promote the synergistic performance of graphene aerogel adsorption and catalytic degradation systems was refined based on experimental and DFT results, providing a new idea for the advanced treatment of wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • DMSO can be loaded onto kaolinite in two mechanisms; intercalation onto kaolinite crystallites and adsorption. • Water influences the mode of bonding between DMSO and kaolinite. • Electrical conductivity and dielectric constant support the adsorption nature of type I DMSO in hydrated DMSO-KCs. • DMSO-KCs composition affects electrical conductivity and dielectric constant data. Kaolin, a naturally occurring clay mineral renowned for its distinctive properties, holds significant importance across various industries. The integration of dimethyl sulfoxide (DMSO) into kaolin matrices, both in the presence and absence of water, has been extensively explored for its potential to enhance material characteristics. Addressing debates surrounding the proposed adsorption mechanism for the type I structure of DMSO, this study undertook a comprehensive physicochemical characterization of DMSO-kaolin complexes (DMSO-KCs) derived from untreated (UnK) and HCl-treated (HK) Egyptian ore, with a focus on elucidating the loading mechanism facilitated by water. Key insights gleaned from electrical conductivity, dielectric constant, and Fine Testing Technology – Fourier-transform infrared (FTT-FTIR) measurements, shedding light on the bonding nature of DMSO-KCs. FTT-FTIR analysis revealed two stages of water departure at 180 °C, with the final stage coinciding with the release of pyrolysis gases, confirming the catalytic degradation of DMSO. Through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), two distinct bonding types of DMSO molecules with kaolinite were identified: amorphous adsorbed (type I) and lattice-oriented intercalated (type II). Electrical characteristic evaluations within the temperature range of room temperature (RT) to 260 °C and frequency range of 42 Hz–1 MHz revealed that DMSO intercalation enhances the electrical properties of kaolin. Hydrated DMSO-KCs exhibited higher values of σ ac and ɛʹ compared to non-hydrated samples. The activation energy (E a) values for HCl-treated samples were smaller than those of untreated ones. Alternating current (AC) conductivity analysis indicated predominantly ionic behavior with frequency and temperature dependency in both HCl-treated and untreated kaolin. Our findings substantiate the adsorption mechanism of Type I DMSO, highlighting its amorphous nature, instability, and catalytic degradation over time, in contrast to the intercalated type II. This elucidation is pivotal for understanding the behavior of DMSO-KCs across diverse applications, including electronics, ceramics, and materials science. [ABSTRACT FROM AUTHOR]