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Nanozyme is a new promising approach to cancer therapy for its ability to induce ferroptosis by activating H2O2 via a traditional radical pathway and enhance cancer immunotherapy. However, short half-life period of hydroxyl radical (·OH) results in unsatisfied effectiveness. Herein, we synthesized a single-atom iron nanozyme (Fe-SAzyme), which can activate H2O2 via a non-radical pathway to generate Fe-based reactive oxygen species (ROS) (O=FeO3=O) for promoting the ferroptosis of pancreatic cancer cells. This Fe-SAzyme could be specifically phagocytosed by pancreatic cancer cells, increasing ROS levels and inhibiting glutathione (GSH) synthesis, which activates ferroptosis. Tumor magnetic resonance imaging (MRI) showed decreased T2 signal after intravenous injection of RGD@Fe-AC (AC = activated carbon). Moreover, RGD@Fe-AC promoted dendritic cell (DC) maturation, overcame Treg-mediated immunosuppression, activated T cells to trigger adaptive immune responses, and enhanced the efficacy of α-PD-L1 immunotherapy. Our research demonstrated that RGD@Fe-AC provided a straightforward, easily implemented, and selective approach for pancreatic cancer treatment and immunotherapy. [ABSTRACT FROM AUTHOR]

The reuse of powdered activated carbon (PAC) vitally determines the economics and security of the PAC‐based adsorption process, while state‐of‐the‐art PAC regeneration technologies are usually unsatisfactory. Here, it is demonstrated that isolated Fe sites anchored on commercial PAC enable fast H2O2 activation to produce Fe‐based reactive oxygen species for highly efficient PAC regeneration at room temperature. Taking rhodamine B as a representative pollutant, PAC decorated with isolated Fe sites realize H2O2 based regeneration with negligible adsorption capacity degradation for 10 cycles. Moreover, in terms of the PAC loss rate, this technology is greatly superior to traditional Fenton‐based regeneration technology. Further operando experiments and theoretical calculations reveal that the high regeneration performance can be attributed to the isolated HOFeO motifs, which activate H2O2 via a nonradical reaction pathway. These findings provide a very promising strategy toward reducing the cost of H2O2‐based PAC regeneration technology. [ABSTRACT FROM AUTHOR]

The catalytic ozonation-based advanced oxidation process (AOP) is applied to remove nondegradable chemical oxygen demand (COD), while the application in industry is limited by the economics and activity of catalysts. In this study, we demonstrate that by taking atrazine (ATZ) as a model pollutant, the removal rates of catalytic ozonation were negatively correlated with the interlayer water content of metal-modified montmorillonite (M x @MMT), instead of the loadings metals. Among the modified MMT, Zn 0.1 @MMT achieved 83.2% degradation of ATZ within 15 min, and corresponding removal rates of COD and total organic carbon (TOC) reached 40.3% and 46.5%, respectively. Detailed EPR and quenching experiments identified that hydroxyl radicals (HO•) were the main reactive oxygen species and QTOF/MS/MS analysis helped to propose a possible degradation pathway of ATZ. Moreover, the catalytic performance of Zn 0.1 @MMT under different conditions was also systematically evaluated. [Display omitted] • The catalytic activity was negatively correlated with the interlayer water content. • The Zn 0.1 @MMT showed high performance of ATZ degradation. • The mechanism of ATZ degradation was elucidated. • The Zn 0.1 @MMT showed excellent stability and wide applicability. [ABSTRACT FROM AUTHOR]

Sulfonamides have attracted special attention due to their widespread use and refractory nature in the aquatic environment. Heterogeneous catalytic peroxymonosulfate (PMS) activation for sulfonamide degradation has been demonstrated to be an encouraging strategy. Herein, ultrathin nickel aluminium layered double hydroxide (U–NiAl-LDH) was employed as an efficient peroxymonosulfate activator. The adsorption kinetics experiment showed that U–NiAl-LDH exhibited a super-adsorption phenomenon for sulfonamide antibiotics, such as sulfamethoxazole (SMX) and sulfachloropyridazine (SCP). U–NiAl-LDH was composed of 6 layers of a NiAl bimetallic layer structure. The degradation performance of organic contaminants via PMS activation was greatly accelerated by decreasing the number of LDH layers. Ni(II) on the surface of U–NiAl-LDH activated PMS to produce surface-bound hydroxyl radicals and sulfate radicals by donating electrons to cleave the O–O bond of PMS. These in-situ generated reactive oxygen species (ROS) on the surface of U–NiAl-LDH could directly attack adjacent adsorbed SMX or SCP molecules, where the migration distance between the ROS and target contaminants was reduced. Consequently, super-adsorption synergistically promoted the degradation efficiency of SMX and SCP, which decreased the demand for PMS. The newly found ultra-adsorption enhancing peroxymonosulfate activation effect was pioneered for the ultrafast elimination of sulfonamide antibiotics in real water. This proposed mechanism provides preliminary guiding significance to design PMS catalysts with dual reaction sites for the treatment of targeted refractory organic contaminant wastewater. Schematic illustration of possible reaction mechanism of the U–NiAl-LDH and PMS system. [Display omitted] • Ultrathin NiAl-LDH was synthesized by formamide-assisted precipitation method. • U–NiAl-LDH exhibited super-adsorption effect for sulfonamide antibiotics. • Strong electron donating capability contributed to the outstanding PMS activation. • Migration distance between reactive oxygen species and contaminants was reduced. • Sulfonamide antibiotics in real water were rapidly and accurately eliminated. [ABSTRACT FROM AUTHOR]

The ozone activation reaction is becoming more popular with the treatment of organic pollutants, while the key to improving the efficiency heavily lies in the selection of active catalysts. In this study, we demonstrate that synthetic 4A zeolite with a high surface oxygen vacancy density and acidity exhibits excellent activity toward the ozonation process, where the removal rates of atrazine (ATZ) reached 87.5% at 6 min, and the removal rates of Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) reached 66.7% and 35.8% at 15 min, respectively. Compared with commercial 4A zeolite and synthetic 4A zeolite with acid treatment, the ozonation activities of 4A zeolites positively correlate with the surface acidity. Mechanistic investigations have identified that hydroxyl radicals are the main reactive oxygen species, and thus, the degradation pathway of ATZ is provided. Moreover, the influences of catalyst dosage, reaction temperature, pH and cycling stability on ozonation performance are systematically evaluated. (a) Schematic illustration of possible reaction mechanism of the 4A Zeolite + O3 system.(b) Removal of ATZ by catalytic ozonation with all 4A zeolites.(c) EPR for O vacancies of C-4A, S-4A, C-4A-Acid.(d) Reusability of S-4A in catalyst ozonation ATZ. [Display omitted] • A 4A zeolite with high surface acidity is controllably synthesized. • The surface acidity of 4A zeolite is enhanced by introduction of oxygen vacancies. • The designed 4A zeolite shows higher catalytic activity than purchased zeolite. • Oxygen vacancies, as Lewis acid sites, catalyze ozone to produce HO.•. • The designed catalyst shows excellent stability, and wide applicability. [ABSTRACT FROM AUTHOR]