In the present work and for the first time, tuning of the band gap width of the SrTiO3 (STO) perovskite to a value suitable for photocatalytic (PC) and photovoltaic (PV) applications is accomplished by the incorporation of Fe cation. Nanocrystalline SrTi0.9Fe0.1O2.968 (STFO) was prepared by a modified solid state reaction process including successive sequences of milling and calcinations at high temperature. The X-ray diffraction (XRD)pattern revealed the formation of a single cubic perovskite phase of STFO with average crystallite size equaling ⁓30 nm. The local lattice strain on (h00) and (hh0) planes was found to decrease by Fe doping. The absorption spectrum deduced from diffused reflectance showed high intense broad structure extending over the range ⁓0.5– ⁓6 eV, whereas pure STO gave strong absorption only at the UV region (λ < 400 nm). The deduced band gap width of the STFO sample was 1.43 eV; an ideal value for PC and PV applications. Deconvolution of the broad absorption band revealed the presence of four absorption structures attributed to Fe defect centers. The narrowing of the band gap was also confirmed through the photoluminescence study where many emission lines covering the violet-blue region were detected. The type of the Fe species and the relative abundance of Fe3+ and Fe4+ were determined by Mössbauer spectroscopy. The presence of oxygen vacancies and Fe-OV complexes were also supposed as lattice defects located above the O2p and below the Ti-3dt2g states. The novel electronic structure researched in this study offers a new avenue in the field of band gap engineering for future application in the field of photocatalytic materials.

Room temperature soft ferromagnetism has been detected in nanocrystalline ZnO while doping with Bi as a heavy non-magnetic atom. The Zn1-xBixO (x = 0.0, 0.01, 0.03 and 0.05) system was synthesized by chemical coprecipitation. To investigate the origin of this enhanced ferromagnetism, characterization of crystal structure, lattice dynamics, and magnetic properties has been achieved. The presence of only one wurtizite single phase of nanocrystalline ZnO was confirmed through Rietveld analysis. The gradual increase of the c parameter also reflected complete solubility of Bi in the wurtizite lattice up to x = 0.05. Bi was detected to occupy the position 2b (1/3, 2/3, 0) of Zn. A drastic decrease of the crystallite size to less than its half value was also detected. Well defined inter crystallite boundaries were imaged by HR-TEM. ESR studies revealed a moderate increase of the free spin density while the g values gave evidence of the formation of defects like VO+, VZn and (BiZn-VZn) complex. Considerable increase of magnetic moment was found as Bi content increased to 0.05. We believe that the enhancement of ferromagnetism in Bi doped ZnO can be attributed to an ensemble of key factors: free spins, vacancy defects and the formation of nanocrystallites with intergranular layers within a threshold limit.

The main components of teeth and bones are calcium phosphate (CP). Hydroxyapatite (HA) is expected to be used in different fields not only in biomedical applications but also in agriculture as a fertilizer and pollution treatment. Various substitutions in the apatite lattice play a significant role in its properties. In the present work, Hydroxyapatite/Silica nanocomposites were prepared successfully by mechanochemical processing method. The surface characteristics were analyzed by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX). X-ray diffraction analysis indicated that silica addition stimulates the HA decomposition to α- and β- tricalcium phosphate (TCP) which clearly increase with silica content.

Graphene, a legendary 2D nanomaterial, has captured the attention of many scientists in the recent decade for its unique properties and its use in many different high-tech technological applications. However, its well-known “Zero band gap” semiconducting behavior is rather an obstacle in being used as alternative to silicon and germanium compounds in electronic chips. All thoughts were focused on how to open a band gap in a graphene sheet to obtain a reasonable outstanding semiconductor material. To achieve this, a quantum confinement to the graphene sheet band structure is necessary. Consequently, this requires a structural confinement of the graphene sheet turning it into ribbons. These new structures are now famously known by “Graphene Nanoribbons” (GNRs). Interestingly, GNRs can be synthesized with atomic precision through on-surface chemistry of self-assembled organic precursors on metal surfaces. Here we introduce our recent work on growing 7-armchair GNRs on Au (16 14 15) kinked surface. The GNR structure was determined using scanning tunneling microscope (STM) and x-ray photoemission spectroscopy (XPS). Besides, we could detect the occupied frontier band of the GNR at the center of the first Brillouin zone, as predicted in theoretical photoemission calculations, using angle resolved photoemission spectroscopy (ARPES).

A simple micro plasma method was used to synthesize metal oxide (Fe3O4) nanoparticles in aqueous solutions NaCl electrolytic system. Microplasma was successfully used as the cathode and iron electrode immersed in liquid was used as the anode. The metal oxide (Fe3O4) products are characterized by X–ray diffraction (XRD) and transmission electron microscope (TEM). The results show that the morphology of Fe3O4 nanocrystals size obtained by this technology is mainly dependent on the synthesis rate. The uniform sphere Fe3O4 nanoparticles with the size about 4, 15 nm.

Graphitic carbon nitride (g-C3N4) has special features make it a promising material for photocatalytic applications. Also, it offers various applications in solar fuels production through CO2 reduction and water splitting, and environmental remediation through the degradation of organic pollutants. This promise reflects the advantageous photophysical properties of g-C3N4 nanostructures, notably high surface area, quantum efficiency, interfacial charge separation and transport, and ease of modification through either composite formation or the incorporation of desirable surface functionalities. Potential new architectures, such as composite g-C3N4 nanostructures, that may offer further performance enhancements in solar energy harvesting and conversion are also outlined. g-C3N4 nanostructures offer tunable textural, electronic and optical properties that are amenable to tailoring for solar energy harvesting and subsequent photocatalytic transformations for energy and environmental applications. Diverse synthetic methods are available to prepare pure g-C3N4 nanostructures of different dimensionality and porosity and to integrate these within multi-functional nanocomposites with enhanced solar spectral utilization, apparent quantum yields, charge separation and transport, and ultimately photocatalytic activity and stability. Here, we focus on the synthesis and photocatalytic applications of g-C3N4 nanostructured materials.

Mn1-x Znx fe2O4 (x= 0, 0.25, 0.5, 0.75) nanoparticles were successfully synthesized by coprecipitation method at temperature 80oC and PH= 11.5. The structure and morphology of Mn1-x Znxfe2O4 nanoparticles were investigated by X-ray diffraction (XRD) and transmission electron microscope (TEM), while the magnetic properties were studied by vibrating sample magnetometer (VSM). XRD results confirm the formation of single phase spinel ferrite for all synthesized samples. Particle size for all samples estimated via both Scherer equation and TEM found to decrease by increasing Zn content. VSM results showed strong dependence of magnetic parameters on Zn content. The saturation magnetization achieved the maximum value at 0.25 Zn and decreased sharply by increasing the Zn ratio.

The actinobacterium strain was isolating from soil samples, that collected from a place near Mina Coast region, El-Gharbia governorate, Egypt, Identification of the producer strain was performing according to the cell wall, chemo-type analysis, and spore morphology. Results suggested that this strain is a streptomycete. Further cultural, physiological characteristics and analysis of the nucleotide sequence of 16S rRNA gene evidenced a 99% similarity with Streptomyces scopiformis. Zinc oxide nanoparticles (ZnONPs) were synthesizing by a reducing agent (cell-free supernatant of Streptomyces atroverins strain). Further investigation of the shape and size of ZnONPs was doing by UV-Vis, FT-IR, DLS, TEM and X-RD revealed morphology of monodispersed spherical ZnONPs with mean diameter of (ca. 20.74 nm). ZnONPs was showing significant antimicrobial activity against some clinical isolates of Gram-negative, Gram-positive bacteria, fungi and some multi-drug resistant bacteria such as Staphylococcus aureus (MRSA) and ampicillin-resistant Escherichia coli O157:H7. ZnONPs active against some food-borne pathogens. ZnONPs activity assessment as inhibition zone that ranged from 15.0 to 24.0 mm and MIC ranged from 15.62 to 125.0 µg/ml. In vitro study demonstrated the effectiveness of the synthesized ZnONPs as a potent tool in fighting foodborne pathogens and multi-drug resistant bacteria.

20V2O5-30Bi2O3-50P2O5 glass was prepared by traditional quenched melt method. The DC conductivity of the quenched and annealed samples were investigated. The as quenched samples were confirmed by X-ray diffraction (XRD) and differential scanning calorimeter (DSC) techniques. The average crystallite size of the present samples after crystallization at different temperatures were estimated by Scherrer equation to be less than 100 nm. DSC analyses of the glasses indicate a prominent glass transition temperature at 710.6K and crystallization temperature at 825.5K. The conductivity was discussed in conformity with Mott's theory. The crystallinity development reduces the grain boundaries which leads to the conductivity improvement.

Inorganic semiconductor quantum dots are known with their unique optical and electronic properties. The presence of a magnetic transition metal ion in the host-semiconducting matrix is known to form a diluted magnetic semiconductor. The discovery of these materials led to a new field of electronics known as spintronics. Meanwhile, organic semiconductors are acknowledged inexpensive, Flexible, nontoxic and highly mass production materials. Summing all above, we introduce here a new Organic-inorganic hybrid diluted magnetic semiconductor system, with the intent of incorporating the advantages associated with both material groups. In this work, we synthesized a hybrid heterostructure composed of CdS QDs doped with iron phthalocyanine (FePc) molecules, representing the inorganic and organic semiconductors, respectively. The FePc/CdS QDs hybrids were prepared with different FePc concentrations by coprecipitation route using Tri-n-octyl-phosphine oxide (TOPO) as a surfactant. The structural, optical and magnetic properties have been examined with x-ray photoemission spectroscopy (XPS), high-resolution transmission microscopy (HR-TEM), electron diffraction (ED), UV-visible optical absorption, and vibrating system magnetometer, respectively. Upon doping, the magnetic effect of the CdS QDs changed from completely diamagnetic of the pure QDs to a room-temperature superparamagnetic of the hybrid, supporting that FePc doped CdS QDs are appropriate materials for spintronics applications.

Carbon nanotubes (CNTs) are considered one of the most promising graphene nanostructured materials in electronic and optoelectronic devices due to their extraordinary electrical, mechanical, and chemical properties. The properties of these large cylindrical molecules can be effectively modulated throughout their functionalization with different chemical compositions. In this work, we functionalize the multi-walled carbon nanotubes (MWCNTs) with zinc phthalocyanine (ZnPc) oligomers using a very simple chemical method. The structural, optical and electrical properties were comprehensively studied for their deposited solution on Si-wafer aiming to identify their suitable future applications.