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Peroxymonosulfate (PMS) based advanced oxidation processes have gained widespread attention in refractory antibiotics treatment. In this study, Fe 3 O 4 nanoparticles anchored nitrogen-doped porous carbon microspheres (Fe 3 O 4 /NCMS) were synthesized and applied to PMS heterogeneous activation for doxycycline hydrochloride (DOX-H) degradation. Benefitting from synergy effects of porous carbon structure, nitrogen doping, and fine dispersion of Fe 3 O 4 nanoparticles, Fe 3 O 4 /NCMS showed excellent DOX-H degradation efficiency within 20 min via PMS activation. Further reaction mechanisms revealed that the reactive oxygen species including hydroxyl radicals (•OH) and singlet oxygen ( 1 O 2 ) played the dominant role for DOX-H degradation. Moreover, Fe(II)/Fe(III) redox cycle also participated in the radical generation, and nitrogen-doped carbonaceous structures served as the highly active centers for non-radical pathways. The possible degradation pathways and intermediate products accompanying DOX-H degradation were also analyzed in detail. This study provides key insights into the further development of heterogeneous metallic oxides-carbon catalysts for antibiotic-containing wastewater treatment., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Herein, we propose a strategy of rapid assembly of Ag3PO4 nanoparticles (NPs) within three dimensional (3D) keratin–inorganic hybrid nanoflowers (keratin-NF@Ag3PO4) with a facile in situ ion sedimentation approach. The 3D porous networks greatly prevent polycondensation of Ag3PO4 NPs because of the porous and interconnected microstructures, which enhanced the catalytic activity in the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) into a blue colored product (oxTMB) in the presence of H2O2. However, the addition of uric acid (UA) could lead to the reduction of oxTMB, resulting in fast fading of the blue color. Inspired by this finding, a simple and sensitive colorimetric assay for uric acid (UA) has been developed with a detection limit (LOD) of 0.94 μM. Furthermore, this strategy has been successfully applied to the detection of UA in practical samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bimetallic FeNi nanoparticles/straw-derived biochar was synthesized. • biochar reduces the aggregation of Fe0. • Ni doping promotes the formation of Fe(II) and H atoms. • BC@Fe/Ni is a promising material for controlling Cr(VI) pollution. Nano-zero-valent iron (nZVI) can efficiently control Cr(VI) pollution in groundwater, but its application is hindered by the tendency of Fe0 to agglomerate and form a passivation layer. In this study, to increase the reactivity of Fe0, biochar (BC) -supported Fe/Ni bimetal nanoparticles (BC@Fe/Ni) were developed to promptly remove Cr(VI) from water. The results demonstrated that the mesoporous structure of BC can provide a supportive environment for Fe0 and reduce the aggregation of Fe0. The removal efficiency of BC@Fe/Ni was found to be better than that of BC and Fe/Ni. Good performance was achieved when the Ni content was approximately 5%. At pH 2.0, the removal rate of Cr(VI) reached 99.62%. A higher temperature was found to be favorable for the reaction, indicating that BC@Fe/Ni is endothermic in removing Cr(VI). The mechanism of BC@Fe/Ni and Cr(VI) is as follows. First, a part of Cr(VI) is adsorbed on BC@Fe/Ni via electrostatic attraction; then, the driving force for Cr(VI) reduction is mainly the continuous electron transfer of Fe0 and Fe(II); moreover, Ni promotes the formation of Fe(II) and H atoms. In conclusion, this work demonstrates that BC@Fe/Ni is a promising material for controlling Cr(VI) pollution. This work will serve as a reference for the improvement of bimetallic nanomaterials and the treatment of Cr(VI) contamination. [ABSTRACT FROM AUTHOR]

Graphical abstract Hybrid CF@C-Ni has been synthesized by an extended Stöber approach combined with a pyrolysis process, which was convenient to collect and recycle during the application. Highlights • Hybrid CF@C-Ni can be easily obtained with an extended stöber approach and subsequent carbonization treatment in nitrogen atmosphere. • The size and density of nickel NPs on the carbon fabric could be finely controlled by adjusting the carbonization temperature. • The nickel NPs endowed the CF@C-Ni composites with magnetism, exhibiting catalytic performance on the reduction of 4-NP. • The hybrid CF@C-Ni can be easily recycled in the catalytic process due to its cloth structure. Abstract One-dimensional (1D) carbon fabric (CF) anchored with high-density of nickel nanoparticles (NPs) has been successfully fabricated by combining an extended Stöber approach with a carbonization process. Hybrid CF@PDA-Ni2+ was first synthesized by the coating of the polydopamine-Ni2+ (PDA-Ni2+) layer on carbon fabric in a Stöber condition. After carbonizing in an inert atmosphere, the CF@C-Ni hybrid in which plenty of Ni NPs embedded in PDA-derived carbon shell on carbon fabric was obtained. Thus, the prepared CF@C-Ni composites can be employed as the catalyst for the reduction of 4-nitrophenol (4-NP). Additionally, the size and density of Ni NPs could be finely controlled via changing the carbonization temperature. Moreover, the CF@C-Ni composites can be easily collected and recycled with little loss because of their unique structures, which is important for practical applications. [ABSTRACT FROM AUTHOR]

• SnO 2 /MoS 2 nanocomposite ammonia sensor was prepared by hydrothermal synthesis. • SnO 2 /MoS 2 had a flower-like structure with SnO 2 nanocrystals decorated on MoS 2 nanosheets. • SnO 2 /MoS 2 exhibited remarkable sensitivity much higher than that of pure MoS 2. • SnO 2 /MoS 2 showed rapid response and recovery times and excellent selectivity. • SnO 2 /MoS 2 sensors have potential applications in the NH 3 gas-sensing field. In this work, MoS 2 nanosheets decorated with SnO 2 nanoparticles were prepared via a facile two-step hydrothermal method, which possesses a proposed sensing composite structure of supporting layer/sensitive dots. The SnO 2 /MoS 2 nanocomposites exhibited an excellent sensing response (2080.36) toward 200 ppm NH 3 , which was ∼27.5 times higher than that of pristine MoS 2 films, a fast response/recovery time (23/1.6 s) toward 50 ppm at room temperature (22℃), and outstanding selectivity to NH 3 against CH 4 , H 2 , CO, H 2 S, and NO 2 and good repeatability. The excellent gas sensing properties could be dominated by the unique thin layers assembled flower-like structures of 2D MoS 2 , which foster the carrier charge transfer process and the reaction to SnO 2 /MoS 2 and NH 3. These results present the SnO 2 /MoS 2 nanocomposites promising candidate materials for high-performance NH 3 gas sensing at room temperature. [ABSTRACT FROM AUTHOR]