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In this work, we prepared two-dimensional (2D) stack-structured aminopropylIsobutyl polyhedral oligomeric silsesquioxane (POSS-NH

The improper disposal in agricultural and industrial wastewater leads to high NO

Environmental hazards caused by chloramphenicol has attained special attention. Fast, accurate and reliable detection of chloramphenicol in foodstuffs and water samples is of utmost importance. Herein, we developed a g-C

In this work, we prepared two-dimensional (2D) stack-structured aminopropylIsobutyl polyhedral oligomeric silsesquioxane (POSS-NH2) intercalated titanium carbide (Ti3C2Tx) MXene material (Ti3C2Tx/POSS-NH2) using a post-intercalation strategy as a potential adsorbent for the removal of cesium (Cs+) and strontium (Sr2+) ions from aqueous solutions. Ti3C2Tx/POSS-NH2 exhibited unprecedented adsorption capacities of 148 and 172 mg g−1 for Cs+ and Sr2+ ions, respectively. Batch adsorption experimental data well fitted the Freundlich isotherm model, which revealed multilayer adsorption of Cs+ and Sr2+ ions onto heterogeneous –OH, –F, –O, and –NH2 adsorption sites of Ti3C2Tx/POSS-NH2 with different energies. Ti3C2Tx/POSS-NH2 exhibited rapid Cs+/Sr2+ ions adsorption kinetics and attained equilibrium within 30 min. Also, Ti3C2Tx/POSS-NH2 exhibited recyclable capability over three cycles and remarkable selectivities of 89% and 93% for Cs+ and Sr2+ ions, respectively, in the presence of co-existing mono- and divalent cations. We suggest the high adsorption capacity of Ti3C2Tx/POSS-NH2 might be due to the synergistic effects of (i) increased inter-lamellar distance between Ti3C2Tx galleries due to POSS-NH2 intercalation, enabling diffusion and encapsulation of large numbers of Cs+/Sr2+ ions, (ii) strong complexation of amine (–NH2) groups of POSS-NH2 with Cs+/Sr2+ ions, and (iii) the presence of large numbers of heterogeneous surface functional groups (e.g., –OH, –F, and –O), which resulted in the adsorptions of Cs+/Sr2+ ions through electrostatic, ion exchange, and surface complexation mechanisms. Given the extraordinary adsorption capacities observed, intercalation appears to be a promising strategy for the effective removal of radioactive Cs+ and Sr2+ ions from aqueous media.

The improper disposal in agricultural and industrial wastewater leads to high NO2– concentrations in the aquatic environment, which can cause cancer in humans and animals; thus, their quick and accurate detection is urgently needed to ensure public health and environmental safety. In this study, a reliable and selective electrochemical sensor consisting of Pd–Cu nanospheres (NSs) supported on molybdenum carbide was prepared via simple ultrasonication. Then, a glassy carbon electrode was realized using this composite (Pd-Cu-Mo2C-modified GCE) to test its electrocatalytic sensing for NO2– in a 0.1 M phosphate-buffered solution (PBS) solution via cyclic voltammetry and amperometry; at a low oxidation potential, the anodic peak current of NO2– detected by this electrode was significantly higher than that of its unmodified and other modified electrodes. The sensor showed a broad linear response in the 5–165-nM NO2– concentration range, with a low detection limit (0.35 nM in 0.1 M PBS) and high sensitivity (3.308 μAnM–1 cm–2). Moreover, the fabricated electrode was successfully applied for detecting nitrites in sausages, river water, and milk, showing also good recovery.

Heterogeneous photocatalysis has been proven to be a promising approach to overcome the great challenges encountered with conventional technologies for environmental remediation. Herein, for the first time, a novel hierarchical architecture of nitrogen-doped TiO

Environmental hazards caused by chloramphenicol has attained special attention. Fast, accurate and reliable detection of chloramphenicol in foodstuffs and water samples is of utmost importance. Herein, we developed a g-C3N4/MnWO4 composite for the selective and sensitive detection of chloramphenicol. Successful fabrication of g-C3N4/MnWO4 composite was verified by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), x-ray diffraction (XRD) and x-ray photo electron spectroscopy (XPS) techniques. Electrochemical characteristics were evaluated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). The g-C3N4/MnWO4 modified glassy carbon electrode has shown the highest electrocatalytic activity towards chloramphenicol with a decreased reduction potential of -0.547 V and increased cathodic peak current. The developed sensor has shown excellent performance for the detection of chloramphenicol with a sensitivity of 0.9986 μA nM-1 cm-2 and LOD of 1.03 nM in a broad linear range of 4.0-71 nM. In addition, the fabricated sensor has achieved anti-interference ability, good stability, excellent repeatability and remarkable reproducibility for the detection of chloramphenicol. The fabricated sensor applied for the determination of chloramphenicol in milk, human blood serum and sewage samples, in which significant and satisfactory results were achieved.

Heterogeneous photocatalysis has been proven to be a promising approach to overcome the great challenges encountered with conventional technologies for environmental remediation. Herein, for the first time, a novel hierarchical architecture of nitrogen-doped TiO2@Bi2WxMo1-xO6 (N-T@BWMO-x, x = 0–1.0) was rationally designed and fabricated through an electrospinning route followed by a solvothermal process. The photocatalytic activity of the as–prepared samples was evaluated based on the degradation of tetracycline hydrochloride (TC) under visible–light irradiation. The results indicated that the molar fraction of W/Mo has a strong impact on the photocatalytic efficiency and photoelectrochemical performance of the N-T@BWMO composites. Compared to N-TiO2 and the binary composites, N-T@BWMO-0.25 exhibited outstanding photocatalytic activity and significant cycling stability. The enhanced photocatalytic activity can be synergistically linked to the excellent native adsorption, extended light–harvesting region, hierarchical structure, and strong interfacial interaction between N-TiO2 and BWMO, which can effectively prolong the lifetime of charge-carriers. Moreover, active species-trapping and electron paramagnetic resonance results confirmed that holes and superoxide radicals were the dominant active species responsible for TC removal. A possible photocatalytic mechanism underlying the degradation of TC by N-T@BWMO-0.25 is also proposed. We expect that our findings will provide new insights into the use of highly efficient core–shell heterostructure photocatalysts, with potential applications in environmental decontamination.

We illustrate a facile approach for in situ synthesis of Pd-gum arabic/reduced graphene oxide (Pd-GA/RGO) using GA as the reducing agent, which favors the instantaneous reduction of both Pd ions and GO into Pd nanoparticles (NPs) and RGO. From the morphological analysis of Pd-GA/RGO, we observed highly dispersed spherical 5 nm Pd NPs decorated over RGO. The as-synthesized Pd-GA/RGO composite was employed for the catalytic reduction and the electrochemical detection of 4-nitrophenol (4-NP), respectively. The catalytic reduction of 4-NP was highly pronounced for Pd-GA/RGO (5 min) when compared to Pd NPs (140 min) and Pd/RGO (36 min). This enhanced catalytic activity was attributed to the synergistic effect of Pd NPs and the presence of various functional groups of GA. Significantly, the fabricated sensor offered a low detection limit (9 fM) with a wider linear range (2–80 pM) and long-term stability. The simple construction technique, high sensitivity, and long-term stability with acceptable accuracy in wastewater samples were the main advantages of the developed sensor. The results indicated that the as-prepared Pd-GA/RGO exhibited better sensing ability than the other graphene-based modified electrodes. Therefore, the proposed sensor can be employed as a more convenient sensing platform for environmental and industrial pollutants.