Environmental governance by photothermal materials especially for the separation of organic pollutants and regeneration of freshwater afford growing attention owing to their special solar-to-heat properties. Here, we construct a special functional nanosphere composed of an internal silica core coated by a thin carbon layer encapsulated plasmonic bimetallic FeCo2O4 spinel (SiO2@CoFe/C) by a facile self-assembled approach and tuned calcination. Through combining the advantage of bimetallic Fe-Co and carbon layer, this obtained nanosphere affords improved multiple environmental governing functions including peroxymonosulfate (PMS) activation to degrade pollutants and photothermal interfacial solar water evaporation. Impressively, fined bimetal (FeCo) species (20 nm) acted as main catalytic substance were distributed on the N-doping carbon thin layer, which favors electron transfer and reactive accessibility of active metals. The increasing treatment temperature of catalysts caused the optimization of the surface active metal species and tuning catalytic properties in the AOPs. Besides, the incorporation of Co in the SiO2@CoFe/C-700 could enable the improved PMS activation efficiency compared to SiO2@Fe/C-700 and the mixed SiO2@Co/C-700 and SiO2@Fe/C-700, hinting a synergetic promotion effect. The bimetal coupled catalyst SiO2@CoFe/C-700 affords enhanced photothermal properties compared to SiO2@Co/C-700. Furthermore, photothermal catalytic PMS activation using optimal SiO2@CoFe/C-700 was further explored in addressing stubborn pollutants including oxytetracycline, sulfamethoxazole, 2, 4-dichlorophenol, and phenol. The free radical quenching control suggests that both the sulfate radical, hydroxyl radical, superoxide radical, and singlet oxygen species are involved in the degradation, while the hydroxyl radical and singlet oxygen play a dominant role. Furthermore, the implementation of a solar-driven interfacial water evaporation model using SiO2@CoFe/C-700 was further studied to obtain freshwater regeneration (1.26 kg m-2 h-1, 76.81% efficiency), indicating the comprehensive ability of the constructed nanocomposites for treating complicated environmental pollution including organics removal and freshwater regeneration.

Although spinel oxides have been promising in advanced oxidation processes (AOP), multidimensional coupling via bimetallic redox cycles and photothermal synergy is still rare in AOP and environmental governance. Here, ultrafine plasmonic CoFe2O4 spinel nanoparticles (similar to 20 nm) were composited with porous silica and followed by a tuned thermal treatment procedure (600-900 degrees C) in N2 condition to obtain bi-metallic nanocomposites. The resulting catalysts exhibited significant active interfacial effects and an in-creased proportion of Co (II) species in the spinel structure after the calcination process. The CoFe/SiO2-8 nanocatalysts effectively showed significant advantages in size structure and valence modulation compared to CoFe2O4 alone, and the prepared catalysts showed great potential for multiphase PMS activation with better photothermal effects. In addition, the introduction of SiO2 in the CoFe/SiO2-8 catalyst allows a higher activation efficiency of PMS during the catalytic degradation of bisphenol A. We also demonstrated that under photothermal (a simulated sunlight) conditions, 30 ppm BPA can be completely degraded within 30 min by coupling the photothermal effect with the catalyst, which is significantly better than the catalytic degradation behavior of only catalyst-participated BPA, achieving a promotive thermodynamic behavior and conversion efficiency. More importantly, solar-driven interfacial water evaporation by virtue of CoFe/ SiO2-8 was explored to identify the practical potential possibility for the regeneration of freshwater from the polluted water resource. (c) 2023 Elsevier B.V. All rights reserved.

Heterogeneous peroxymonosulfate (PMS) activation for the mineralization of pollutants has attracted growing attention, while alloying bimetal catalysts afford big promises in synergetic catalysis. Here, by an alteration of electrospun precursor, one-dimensional carbon nanofiber (CNF) integrated with Prussian blue analogs (PBA)-derived alloyed fine plasmonic FeNi3 hybrid catalyst (FeNi3@CNF) was constructed by electrospinning technique with subsequent confinement calcination. The amount of PBA in fiber precursor and thermal treatment tem-perature were alternatively adjusted to control the distribution and concentration of alloyed FeNi3 in carbon nanofiber. This unique structure combines the advantages of abundant internal porosity of N-doping carbon fiber and uniforms active FeNi3 alloys with highly-exposed reactive sites, facilitating the electron transport and proximity of reactant molecules in catalytic oxidation. The synergistic and interfacial effect of optimal FeNi3@CNF endowed the ultra-fast degradation activity against bisphenol A (BPA) through rapid persulphate activation to generate four reactive active species. Specifically, 20 mg L-1 of BPA was completely degraded within 4 min with a reaction rate constant of 2.736 min-1. Impressively, by innovating the utilization of the Prussian blue precursor in electrospinning, the optimal FeNi3@CNF shows 18.5, 101.3, and 248.5 times activity enhancement in BPA degradation compared to that of Fe@CNF, Ni@CNF, and Fe & Ni@CNF, revealing the appreciable synergy of bimetallic alloys in PMS activation. In addition, the improved catalytic performance of FeNi3@CNF under light irradiation was also simulated, confirming that the enhanced photothermal conversion ability of plasmonic alloys and carbon fiber advance the degradation of BPA.

Photothermal materials afford growing interest in environmental governance, especially for addressing complicated environmental issues including the purification of wastewater and regeneration of freshwater together. Here, we constructed a dual-functional photothermal nanosphere by integrating ultrafine plas-monic Co3O4 (similar to 10 nm) into an N-doping carbon layer over silica nanosphere (SiO2@Co/C). Biocompatible dopamine coating induces the incorporation of Co precursor and activity optimization of metal species over the SiO2 nanosphere during the synthetic process. In this way, the SiO2 nanosphere maintains the stable configuration of the carbon coating thin layer to accommodate the local interfacial Co3O4 catalytic active substances. Impressively, this catalyst also owns a well-developed interconnecting N-containing network structure, unconventional redox cycle pair of Co(II)/Co(III), and significant metal-carbon interaction. A controlled thermal procedure (500-800 degrees C) was implemented to tune the optimized activity state of the catalyst. Under these merits, advanced oxidation process (AOPs) through activating persulfate by the ob-tained materials to degrade organic pollutants was performed in the presence/absence of sunlight, further validating the appreciable photothermal effect to improve the catalytic thermodynamic behavior. The re-action parameters ad anion interference were studied in detail, and SiO2@Co/C-60 0 can completely degrade bisphenol A (BPA) (30 mg L-1) with a high reaction rate constant of 0.722 min -1 and a low reaction activation energy of Ea (19.4 kJ/mol), and also shows superior mineralization activity for some stubborn pollutants, including oxytetracycline (OTC), 2,4-dichlorophenol and tetracycline (TC) through the reinforced photo -thermal approach. Besides, SiO2@Co/C-60 0 shows multiple functions in interfacial solar water evaporation application (1.36 kg m-2 h-1, 81.59 %), revealing great potential value of purification and regeneration of water in the complex pollution condition. This work gives the possibility for the next-generation versatile and competitive photothermal environmental governing materials. (c) 2023 Elsevier B.V. All rights reserved.

Photothermal material applied in environmental governance has attracted growing attention. By combining the Stöber method and dopamine-triggered coating strategy, Co-Mn precursor was in situ incorporated into the polydopamine (PDA) layer over the surface of silica cores. Afterwards, a unique photothermal nanosphere with SiO2 core and thin carbon layer and dual Co-Mn oxides shell was allowed to form by sequential heat treatment in the inert atmosphere (SiO2@CoMn/C). The bimetallic fraction of Co/Mn in the carbon layer and post-treatment calcination temperature was comprehensively tuned to optimize the peroxymonosulfate (PMS) activation performance of the catalyst. The state of bimetallic species was studied including their physical distribution, chemical valence, and interplay by various characterizations. Impressively, Co oxides appear as dominant monodispersed nanoparticles ( 10 nm), while Mn with cluster-like morphology is observed to uniformly distribute over thin-layer carbon and adhered to the surface of SiO2 nanospheres ( 250 nm). The calcined temperature could tune the oxidized state of Co species, leading to the optimization of the catalytic performance of introduced dual metal species. As a result, this obtained optimal catalyst integrated the advantages of exposed bimetallic CoMn species and N-doped thin carbon to deliver excellent catalytic PMS activation performance and photothermal synergetic catalytic mineralization ability for diversiform pollutants. Further reactions condition controls and anion interference studies were conducted to identify the adaptability of the optimal catalyst. Moreover, the application of solar-driven interfacial water evaporation using optimal SiO2@Co3Mn1/C-600 catalyst was explored, showing a high water evaporation rate of 1.48 kg·m−2·h−1 and an efficiency of 95.2