A self-assembly of pyridine-2,6-dicarboxylate with Cu(II) and Mn(II) under ultrasonic and microwave irradiation gave the two coordination polymers [Cu(PDA)(H2O)1.5]n (1) and [Mn(PDA)(H2O)1.5]n (2). Their structures were characterized using IR, elemental analysis, X-ray diffraction (XRD) and spectroscopic methods. The corresponding α-Mn3O4 and CuO nanoparticles were synthesized by calcination of 1 and 2 in air at 600 °C.Transmission electron microscopy (TEM) reveals a sphere-like morphology for the Mn3O4 nanoparticles. Shrinkage of the particle size from 90 nm (by conventional synthesis of the precursor) to 19 nm (ultrasonicassisted) takes place, indicating the great effect of ultrasonication. CuO nanoparticles were of semispherical (conventional and ultrasonic-assisted methods) and hexagonal shapes (microwave irradiation) with an average diameter of 7, 15 and 25 nm, respectively. The catalytic performance of the coordination polymers towards degradation of methylene blue and methyl orange in the presence of hydrogen peroxide was studied. Using the same dose, catalyst 1 proved to be more efficient in color removal of both MB and MO than catalyst 2 did. Recycling test for 2 showed that it is a recyclable catalyst with no structural changes over three recycling experiments.

A self-assembly of pyridine-2,6-dicarboxylate with Cu(II) and Mn(II) under ultrasonic and microwave irradiation gave the two coordination polymers [Cu(PDA)(H2O)1.5]n (1) and [Mn(PDA)(H2O)1.5]n (2). Their structures were characterized using IR, elemental analysis, X-ray diffraction (XRD) and spectroscopic methods. The corresponding α-Mn3O4 and CuO nanoparticles were synthesized by calcination of 1 and 2 in air at 600 °C.Transmission electron microscopy (TEM) reveals a sphere-like morphology for the Mn3O4 nanoparticles. Shrinkage of the particle size from 90 nm (by conventional synthesis of the precursor) to 19 nm (ultrasonicassisted) takes place, indicating the great effect of ultrasonication. CuO nanoparticles were of semispherical (conventional and ultrasonic-assisted methods) and hexagonal shapes (microwave irradiation) with an average diameter of 7, 15 and 25 nm, respectively. The catalytic performance of the coordination polymers towards degradation of methylene blue and methyl orange in the presence of hydrogen peroxide was studied. Using the same dose, catalyst 1 proved to be more efficient in color removal of both MB and MO than catalyst 2 did. Recycling test for 2 showed that it is a recyclable catalyst with no structural changes over three recycling experiments.

Coordination polymers acquired much interest due to their powerful applications. Herein, coordination polymer of the formula {[Fe(PZDC)Cl(H2O)2]}n has been prepared conventionally and ultrasonically. The structure was investigated using elemental analysis, IR and X-ray diffraction (XRD). The ultrasonic-assisted synthesis steers the formation of the crystalline coordination polymer while the conventional method leads to the amorphous phase. Calcination of the synthesized coordination polymers was made in glass tubes (length ¼ 200 mm and width ¼ 15 mm) under air at variable temperatures. Depending on the calcination conditions, different iron oxide phases/polymorphs were produced. Maghemite; γ-Fe2O3 was formed by heat-treatment at 350 �C for 1 h regardless of the synthesis way of the precursor. X-ray single phase of hematite; α-Fe2O3 was obtained by calcination of the conventionally prepared precursor at 450 �C for 1 h. Nitrogen adsorption-desorption isotherms showed that, the specific surface areas of the γ-Fe2O3 (conventionally produced precursor), γ-Fe2O3 (ultrasonically formed precursor) and α-Fe2O3 are 125, 132 and 30.5 m2g-1, respectively. Magnetic measurements showed that the best properties are exhibited by γ-Fe2O3 NPs synthesized from the conventionally prepared precursor; highest values of saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) are obtained.On the other hand α-Fe2O3 showed the lowest magnetic properties. The activity of prepared coordination polymers and iron oxide phases for removal of methylene blue (MB) was tested. γ-Fe2O3 (conventionally formed (precursor) showed the highest adsorption efficiency (~22%). On the other side, the coordination polymer (conventionally prepared) exhibited the best removal efficiency of methylene blue in a Fenton-like process. Degradation efficiency of 97.2% was achieved in a very short time (15 min).

Simple and eco-friendly method was developed for synthesis of silver nanoparticles (Ag NPs) via reduction of Ag+ by aqueous Grape leaves extract (GLE). Temperature induced synthesis of Ag NPs was performed and compared to photo-irradiation based method. Formation of Ag NPs was elucidated by both UV–vis spectroscopy and the change of color of the aqueous solution. The formation of Ag NPs is highly influenced by the reaction temperature. The higher the reaction temperature, the faster is the formation of Ag NPs. Phase composition, lattice strain and crystallinity of Ag NPs were analyzed by XRD. The prepared Ag NPs are stabilized by the presence of organic compounds originating from GLE which was proved by both XRD and FTIR analysis. TEM investigation of the synthesized Ag NPs showed that they are highly crystalline in nature and have sphere-like morphology with an average diameter of ~20 nm. The obtained Ag NPs showed efficient antibacterial activity against some Gram +ve and Gram –ve bacteria, particularly Staphylococcus aureus (+ve) and Pseudomonas aeruginosa (−ve).

Simple and eco-friendly method was developed for synthesis of silver nanoparticles (Ag NPs) via reduction of Ag+ by aqueous Grape leaves extract (GLE). Temperature induced synthesis of Ag NPs was performed and compared to photo-irradiation based method. Formation of Ag NPs was elucidated by both UV–vis spectroscopy and the change of color of the aqueous solution. The formation of Ag NPs is highly influenced by the reaction temperature. The higher the reaction temperature, the faster is the formation of Ag NPs. Phase composition, lattice strain and crystallinity of Ag NPs were analyzed by XRD. The prepared Ag NPs are stabilized by the presence of organic compounds originating from GLE which was proved by both XRD and FTIR analysis. TEM investigation of the synthesized Ag NPs showed that they are highly crystalline in nature and have sphere-like morphology with an average diameter of ~20 nm. The obtained Ag NPs showed efficient antibacterial activity against some Gram +ve and Gram –ve bacteria, particularly Staphylococcus aureus (+ve) and Pseudomonas aeruginosa (−ve).

Identification of defect chemistry and variation of particle size are key factors for understanding many intrinsic properties of materials. Herein, size selective synthesis of Mn3O4 nanoparticles was performed by precipitation of Mn(OH)2 via NaOH or ammonia followed by air oxidation in ethanol/water solution. The amount of ethanol in water affects the average particle size that drops from ~25 nm in pure water to ~10 nm in 95% EtOH/H2O. TEM studies showed that the Mn3O4 samples have a sphere-cube like morphologies. Calculation of SOF and unit cell parameters via Rietveld analysis and the excess mass of Mn3O4 samples depending on size by TGA and IR revealed that the cationic deficiency observed in the structure of the smallest size sample is compensated mainly by anionic vacancies. Ideal spinel structure was found for largest size sample. The degree of tetragonal distortion (c/√2 a) of Mn3O4 unit cell increases with particle size.

Two different MnO2polymorphs, namely akhtenskite (ε-form) and nsutite (g-form) were obtained fromthe comproportionation reaction between Mn2þand MnO4. The conditions that administer the trans-formation between both phases i.e. temperature, reflux time and concentration of reactants wereexplored. Other manganese oxide/hydroxide phases are obtained depending on variation of the pH of themedium or the solvent used in the reaction. Heat-treatment of both MnO2polymorphs was done underisothermal and non-isothermal conditions, various pathways were adopted in both cases. The results ofTGA/DTA analysis showed also thatg-MnO2is more stable thanε- MnO2and thatε-form contains muchmore excess mass over its surface (i.e. surface bound hydroxyl groups) thang-form. Surface area mea-surements revealed that the reaction temperature has pronounced effect not only on the product phasebut also on its surface properties. Very high surface area of 345 cm2/g was adopted byε-MnO2anddecreases with increasing of reaction time (239 m2/g). SEM investigations showed thatg-MnO2has aplate-like shape whilstε-MnO2exhibits a sponge-like morphology. Magnetic properties of both oxideswere explored using SQUID magnetometer under zerofield cooled andfield cooled conditions. Bothphases showed a ferromagnetic spin ordering with Curie temperature as 45 K forg-form and 20 K forε-form. The coercive force was found as 2500 and 2130 Oe, respectively. Remanent magnetization was 35and 30 emu mol1forg- andε-MnO2, respectively.

A zinc coordination polymer derived from pyridine‐2,6‐dicarboxylate (PDC), {[Zn2(PDC)2]}n, was successfully prepared via conventional, sonication and microwave‐irradiation methods. The composition and characteristics of the obtained coordination polymers (CPs) were investigated by elemental analysis, TGA/DTA, X‐ray diffraction and spectroscopic techniques. The so obtained CPs were heat‐treated in the air at 600 °C for 2 h to produce ZnO of nanosized particles (NPs). It is of interest to note that the synthesis approach of the precursor greatly affects both the nanoparticle size and the structure of the resulting ZnO NPs. Moreover, the smallest particle size was associated with the sample derived from the ultrasonically prepared precursor. TEM analysis revealed that all samples have sphere‐like morphologies. Structural analysis of the prepared ZnO samples was conducted and compared using Rietveld analysis of their PXRD patterns. Optical band gap calculations based on analysis of the UV–vis spectra of ZnO samples using Tauc's power law were achieved. The highest band gap of 3.63 eV was observed for ZnO sample obtained from the ultrasonically prepared precursor. Furthermore, the photocatalytic activity of ZnO NPs for the removal of Eosin Y color was monitored. The highest removal efficiency was recorded for ZnO originated from the ultrasonically synthesized precursor. Enhancement of removal efficiency that reached 98% was attained in only a period of 8 min. Its recycling test showed that it can be reused without structural changes over four cycling experiments.

A zinc coordination polymer derived from pyridine‐2,6‐dicarboxylate (PDC), {[Zn2(PDC)2]}n, was successfully prepared via conventional, sonication and microwave‐irradiation methods. The composition and characteristics of the obtained coordination polymers (CPs) were investigated by elemental analysis, TGA/DTA, X‐ray diffraction and spectroscopic techniques. The so obtained CPs were heat‐treated in the air at 600 °C for 2 h to produce ZnO of nanosized particles (NPs). It is of interest to note that the synthesis approach of the precursor greatly affects both the nanoparticle size and the structure of the resulting ZnO NPs. Moreover, the smallest particle size was associated with the sample derived from the ultrasonically prepared precursor. TEM analysis revealed that all samples have sphere‐like morphologies. Structural analysis of the prepared ZnO samples was conducted and compared using Rietveld analysis of their PXRD patterns. Optical band gap calculations based on analysis of the UV–vis spectra of ZnO samples using Tauc's power law were achieved. The highest band gap of 3.63 eV was observed for ZnO sample obtained from the ultrasonically prepared precursor. Furthermore, the photocatalytic activity of ZnO NPs for the removal of Eosin Y color was monitored. The highest removal efficiency was recorded for ZnO originated from the ultrasonically synthesized precursor. Enhancement of removal efficiency that reached 98% was attained in only a period of 8 min. Its recycling test showed that it can be reused without structural changes over four cycling experiments.

A zinc coordination polymer derived from pyridine‐2,6‐dicarboxylate (PDC), {[Zn2(PDC)2]}n, was successfully prepared via conventional, sonication and microwave‐irradiation methods. The composition and characteristics of the obtained coordination polymers (CPs) were investigated by elemental analysis, TGA/DTA, X‐ray diffraction and spectroscopic techniques. The so obtained CPs were heat‐treated in the air at 600 °C for 2 h to produce ZnO of nanosized particles (NPs). It is of interest to note that the synthesis approach of the precursor greatly affects both the nanoparticle size and the structure of the resulting ZnO NPs. Moreover, the smallest particle size was associated with the sample derived from the ultrasonically prepared precursor. TEM analysis revealed that all samples have sphere‐like morphologies. Structural analysis of the prepared ZnO samples was conducted and compared using Rietveld analysis of their PXRD patterns. Optical band gap calculations based on analysis of the UV–vis spectra of ZnO samples using Tauc's power law were achieved. The highest band gap of 3.63 eV was observed for ZnO sample obtained from the ultrasonically prepared precursor. Furthermore, the photocatalytic activity of ZnO NPs for the removal of Eosin Y color was monitored. The highest removal efficiency was recorded for ZnO originated from the ultrasonically synthesized precursor. Enhancement of removal efficiency that reached 98% was attained in only a period of 8 min. Its recycling test showed that it can be reused without structural changes over four cycling experiments.