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The present study explores the uptake capacity of low-cost agricultural waste for the removal of heavy metals, Co2+, Cd2+ and Zn2+, from aqueous solution. Studies conformed to Freundlich, Langmuir and Temkin adsorption isotherms. The values of constants for the thermodynamic and kinetic isotherms were found. The kinetic isotherm experiment data could be well described with the pseudo-second order kinetic model and thermodynamic studies indicated that the adsorption processes were spontaneous and endothermic with orange tree leaves under natural conditions. Experiments showed that Cd2+, Co2+ and Zn2+ adsorption increased with increasing pH and decreased with increasing the temperature and concentration of solutions. This study indicates that the developed method based on orange tree leaves is very simple, low-cost, fast and trusty for the removal of heavy metal ions from water and wastewater samples.

The nanoporous activated carbon (AC) was prepared from the eucalyptus leaves via chemical activation with KOH, then treated with nitric acid/ /urea (NOAC) and finally used as a new adsorbent for simultaneous ultrasound- assisted removal of basic red 46 (BR46) and basic yellow 13 (BY13) dyes from binary aqueous solutions. The NOAC nano-adsorbent was characterized with SEM, TEM, Raman, BET, FTIR, CHN, pHpzc and Boehm titration analysis. Both of the AC and NOAC samples had superior BET surface area of 2222 and 1572 m2 g-1 with average micropore volume of 0.81 and 0.50 cm3 g-1, respectively. First order derivative spectrophotometric method was used for analysis of BY13 in binary mixtures. Small amount of the adsorbent (30 mg) was capable to remove high percentage of dyes (>99 %) in a very short time (8 min). The adsorption of dyes follows the Langmuir isotherm and the pseudo- -second-order kinetics. The adsorption capacities of NOAC for single solutions of BR46 and BY13 were 1111 and 1250 mg g-1 as well as for binary solutions were 769 and 909 mg g-1, respectively. The adsorption thermodynamics were also explored. Exhausted NOAC was regenerated using HCl (2 M) and reused for five adsorption-desorption cycles with high performance.

In this study, sulfur‐enriched microporous organic polymer (MOP) was prepared using one‐pot Shiff‐base type polycondensation reaction of thiophendicarboxaldehyde with melamine. With 195.731 m2 g−1 surface area and 0.047 cm3 g−1 pore volume, the as‐synthesized MOP has a cotton‐like morphology and a micropore‐dominated pore size distribution. After loading MOP with nickel as a co‐catalyst, we demonstrated that the obtained framework could be used as an efficient and robust electrocatalyst for hydrogen evolution reaction (HER) in an alkaline medium with the optimum composite (Ni2@MOP) exhibiting a low onset potential of −66 mV. Furthermore, the optimum electrocatalyst showed good stability, delivering 91% faradaic efficiency (FE) after a 3.5 h chronoamperometry experiment. [ABSTRACT FROM AUTHOR]

We report here the synthesis and characterization of a water dispersible conjugated polymer nanoparticle‐based photosensitizer and its application in the antibacterial and anticancer phototherapies. Nanoparticles (CPPN) were synthesized in one‐pot by nanoprecipitation method, in which a hydrophobic azide functionalized, red‐emitting thiophene‐benzothiodiazole based conjugated polymer (CP‐AZ) was cross‐linked with a hydrophilic, propargylamine functionalized porphyrin (TPP‐4AL) through cucurbit[6]uril (CB6) catalyzed azide‐alkyne cycloaddition (CB6‐AAC) reaction. CPPN demonstrated high stability in aqueous medium for more than a month without any visible aggregation and appeared to be a good photosensitizer with high light‐triggered reactive oxygen species (ROS) generation ability. Consequently, CPPN displayed photo‐induced biocidal activity against Gram‐negative (Escherichia coli, E. coli) and Gram‐positive (Bacillus subtilis, B. subtilis and Staphylococcus aureus, S. aureus) bacteria. When bacteria suspension was incubated with CPPN (20 μg ml−1) and irradiated with white light (22 mW cm−2) for 10 min, more than 3.5‐log reduction in colony‐forming units (CFUs) was recorded for the three model bacteria. CPPN demonstrated minimal dark cytotoxicity against the bacteria. Moreover, the cytotoxicity of CPPN on mammalian cell was studied using MCF‐7 breast cancer cell line. The results demonstrated that CPPN is non‐toxic to mammalian cells in the dark even at a high concentration of 112.5 μg ml−1 and this feature makes CPPN an ideal photosensitizer. [ABSTRACT FROM AUTHOR]

Visible‐light triggerable, stable, organic material‐based photocatalysts that can function in alkaline media without the necessity of sacrificial agent for hydrogen production are highly sought after. Here, we report a novel supramolecular photocatalyst that confers the aforementioned features. This supramolecular photocatalyst (TPP‐4CB7) is synthesized through the conjugation of monohydroxylated cucurbit(7)uril (CB7) hosts to a suitably substituted tetraphenyl porphyrin. Although TPP‐4CB7 by its own preforms as an efficient visible light triggered photocatalyst, the hydrogen production efficiency is significantly enhanced upon mixing with TiO2. The resulting nanocomposite (TPP‐CB‐TiO2@Pt) is observed to exhibit remarkable electrophotocatalytic activity under visible light and produces hydrogen (onset potential −10 mV, turn over frequency (TOF) 0.202 s−1, 24.5 mmol h−1 g−1) from water splitting without any significant degradation during four runs (5 h each) in alkaline media and in the absence of sacrificial agent. [ABSTRACT FROM AUTHOR]

Here we report the preparation of water-dispersible glycosylated poly(2,5′-thienylene)porphyrin based nanoparticles by a nanoprecipitation method and demonstrate the application of these nanoparticles in antibacterial photodynamic therapy. The diameter of the nanoparticles is in the range of 50–80 nm and the resulting nanoparticles are stable in water without precipitation at least for a month. They have high singlet oxygen efficiency and display light-triggered biocidal activity against both Gram negative bacteria (Escherichia coli, E. coli) and Gram positive bacteria (Bacillus subtilis, B. subtilis). Upon white light irradiation for 10 min with a flux of 22 mW cm−2 of the E. coli suspension incubated with NPs (18 μg mL−1), a killing efficiency of 99% is achieved, whereas in the dark the effect is recorded as only around 8%. [ABSTRACT FROM AUTHOR]

A sensitive and simple method has been established for simultaneous preconcentration of trace amounts of Pb (II) and Ni (II) ions in water samples prior to their determination by flame atomic absorption spectrometry. This method was based on the using of a micro-column filled with graphene oxide as an adsorbent. The influences of various analytical parameters such as solution pH, adsorbent amount, eluent type and volume, flow rates of sample and eluent, and matrix ions on the recoveries of the metal ions were investigated. Using the optimum conditions, the calibration graphs were linear in the range of 7–260 and 5–85 μg L−1with detection limits (3Sb) of 2.1 and 1.4 μg L−1for lead and nickel ions, respectively. The relative standard deviation for 10 replicate determinations of 50 μg L−1of lead and nickel ions were 4.1% and 3.8%, respectively. The preconcentration factors were 102.5 and 95 for lead and nickel ions, respectively. The adsorption capacity of the adsorbent was also determined. The method was successfully applied to determine the trace amounts of Pb (II) and Ni (II) ions in real water samples. The validation of the method was also performed by the standard reference material. [ABSTRACT FROM AUTHOR]

Front Cover: Novel Supramolecular Photocatalyst Based on Conjugation of Cucurbit[7]uril to Non-Metallated Porphyrin for Electrophotocatalytic Hydrogen Generation from Water Splitting (ChemCatChem 13/2019) B The Front Cover b shows solar energy promoted photoelectrocatalytic water splitting for hydrogen generation using a supramolecular photocatalyst. In their Communication, Dönüs Tuncel and co-workers synthesize a novel, visible light triggerable, stable supramolecular photocatalyst based on conjugation of cucurbit[7]uril to non-metallated porphyrin. [Extracted from the article]