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A cost-effective and simple method has been developed for the preparation of flower-like hierarchical spheres of semiconductor oxide materials. Efficient self-assembly of BiVO4 flower-like hierarchical spheres was performed via a simple hydrothermal method, followed by calcination at 500 °C. X-ray diffraction (XRD) studies distinguished diffraction planes of the monoclinic BiVO4 phase, which was further confirmed by field emission scanning electron microscopy (FESEM) analysis. The electronic and optical properties of BiVO4 were studied via X-ray photoelectron spectroscopy (XPS) and UV-visible spectroscopy. XPS analysis confirmed the binding energy relations and the formation of BiVO4, and also an increase in the Bi–O, V–O bond strengths in BiVO4. The remarkable efficiency of pseudocapacitor electrode materials depends on the consistent fabrication of nano architectures. The carbon-free BiVO4 electrodes showed a higher specific capacitance of 1203 F g−1 at 2 A g−1, without detectable degradation after 2000 cycles and a beneficial cycling stability was achieved because of the electrochemical activity of the distinctive porous hierarchical architecture. Our synthetic method suggests a simple procedure for the design and fabrication of bismuth vanadate hierarchical nano architectures, encouraging electrochemical energy storage. These nanocomposites could be utilized as anode materials in lithium-ion batteries.

Modification of semiconductor oxides leads to a major development in functional characteristics. Characterisation of Pr6O11-TiO2, fabricated by a cost-effective hydrothermal – decomposition method reveals the nanorod like structure of this catalyst. The XRD pattern definite the formation of face-centred cubic or cubic close-packed structure of Pr6O11 and the high crystallinity indicate the existence of anatase TiO2. XPS analysis indicates the presence of both Pr3+and Pr4+ ions in Pr6O11. Pr6O11-TiO2 is more photoactive under visible light than Pr6O11, prepared TiO2 and TiO2-P25 (80% Anatase and 20% Rutile mixture) in the degradation of toxic azo dyes. Pr6O11-TiO2 is stable and recyclable consecutively. Pr6O11-TiO2 catalyst shows higher electrocatalytic activity in methanol oxidation than pure TiO2. These results reveal new insights on the efficiency of catalysts in photo- and electrocatalytic applications.

A new fluorescent sensor 2-(2-(3-chloro-4-fluorophenyl)hydrazono)-5,5-dimethyl cyclohexane-1,3-dione (A) and 2-(2-(4-chloro-2-nitrophenyl)hydrazono)-5,5-dimethyl cyclohexane-1,3-dione (B) composed of a β-diketones of aryl hydrazones synthesized by simple and cost-effective method. Various analytical tools analyzed the structural investigations of the synthesized substituted β-diketones of aryl hydrazones like FT-IR

Initially, novel Cd3(PO4)2 was prepared via precipitation method. It was loaded with different concentration of rGO to form rGO/CdP composites. The prepared rGO/CdP were used to degrade Basic Violet 10 (BV 10) dye under UV-A light irradiation. The optimized rGO/CdP composite was characterized along with pristine CdP and rGO by XRD, FT-IR, FT-Raman, BET, HR-SEM with EDX, HR-TEM, and UV-DRS analysis. The effect of initial dye pH in the degradation was studied. The coupled semiconductor system enhanced the photocatalytic activity and used for multiple runs, due to its remarkable stability.

To replace the existing noble-metal-based catalysts, developing highly efficient, stable electrocatalysts for oxygen reduction reactions for the increased current generation with lower overpotential is a demanding undertaking. In the present work, CuO-NiO/rGO nanocomposites were prepared using simple, cost-effective Co-precipitation methods. They act as highly effective electrocatalysts for oxygen reduction reactions in an alkaline medium. The structural characterizations demonstrate that prepared nanoparticles (≈13 nm) are tightly and effectively organized on reduced graphene oxide sheets. The electrochemical properties of the CuO, NiO nanoparticles and CuO-NiO, CuO-NiO/rGO nanocomposites were investigated. The results of the CuO-NiO/rGO nanocomposites revealed the high current density (2.9 × 10

In this article, we report fabrication of 5 wt% of Dy as DyVO4 supported ZnO by template-free hydrothermal-thermal decomposition method and its photocatalytic activity towards degradation of azo dyes Rhodamine-B (Rh-B) and Trypan Blue (TB) in solar light, Electrocatalytic activity in methanol oxidation and Self-cleaning properties. The as prepared DyVO4-ZnO was characterized by surface analytical and spectroscopic techniques. The results suggested that Dysprosium vanadate doping on ZnO has increased its photocatalytic efficiency with high reusability. DyVO4-ZnO exhibits higher electrocatalytic activity than prepared ZnO for methanol electrooxidation in alkaline medium, revealing its promising potential as the anode in direct methanol fuel cells. Hydrophobicity of ZnO increases by doping of DyVO4.

Heterostructured mixed oxide BiVO4-ZnO is used as semiconductive photocatalyst for the degradation of simulated wastewater from tannery industry in the presence of sun light at neutral pH by semiconductive photocatalysis. The mixed oxide catalyst showed higher degrading efficiency in comparison to bare ZnO and bare BiVO4 metal oxides. Analysis of FESEM and AFM images reveals that particles are in the range of 40 nm and mixed oxide catalyst exhibit uniform porous structure respectively. The crystallinity and planes of the catalysts were studied by XRD analysis. The optical band gap of the mixed oxide catalyst (3.02 eV) was examination by UV–Vis diffuse reflectance spectroscopy. The higher catalytic activity with BiVO4-ZnO is attributed to the change in charge carrier equilibrium at the interface of mixed oxide catalyst, which in turn reduces the recombination rate of electron hole pairs and also decreases the energy gap suitable for degradation in solar light. Under the optimal experimental conditions, 64% reduction in COD has been observed with heterostructured BiVO4-ZnO catalyst in six hours of reaction in the presence of sun light.

Self-cleaning fabrics decorated with titanium dioxide (TiO2) nanoparticles (NPs) have garnered worldwide attention due to their outstanding ultraviolet (UV) light-shielding, anti-bacterial properties and other characteristics. Numerous techniques to construct super-antiwetting surfaces have been investigated for both fundamental research and practical application. A facile and eco-friendly way by a combination of UV irradiation and ultrasonic bath method has been developed to prepare a novel self-cleaning hybrid polyamine 6/nano TiO2 (PA6/nano TiO2) fabric with superhydrophobic and durable photocatalytic properties. To evaluate the fabric's reusability, hybrid PA6/nano TiO2 fabrics were subjected to five consecutive cycles of the photocatalytic degradation of the methyl orange (MO) dye. The results indicated that TiO2 NPs were firmly fixed on the fiber surface. The UV-blocking and anti-microbial properties of these hybrid fabrics were also tested. For PA6 immobilized by commercial nano TiO2-P25 (P25-PA6) and PA6 immobilized by prepared visible-light photocatalyst PVAD-TiO2(PVAD-PA6) fabrics, the UV protection factors (UPFs) of the samples were 56 and 1123, respectively. The anti-microbial efficacies of the two samples were both 99%. The water contact angles were 151.7° and 154.6°, respectively, indicating surface superhydrophobicity. These results showed that this novel fabric has great potential for indoor environmental purification and outdoor protection applications.

Ever growing research on modified semiconductor oxides made a significant progress in catalytic functional materials. In this article, we report the modification of ZnO photocatalyst by a simple hydrothermal decomposition method utilizing the cheaply available industrial waste fly ash. This modified Fly ash-ZnO photocatalyst was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HR-TEM), Atomic force microscopy (AFM), photoluminescence spectroscopy (PL) and diffuse reflectance spectroscopy (DRS). The XRD pattern indicates the presence of fly ash components and the hexagonal wurtzite structured ZnO. TEM images reveal well defined nanorod like structure. Reduction of photoluminescence intensity of Fly ash-ZnO at 418 nm, when compared to, prepared ZnO, indicates the suppression of recombination of the photogenerated electron–hole pair by loaded Fly ash on ZnO. Fly ash-ZnO exhibits enhanced photocatalytic activity for the degradation of azo dyes Reactive Orange 4, Rhodamine-B and Trypan Blue. This catalyst shows higher electrocatalytic activity than ZnO in the oxidation of methanol. Significant hydrophobicity of Fly ash-ZnO reveals its self cleaning property.

Elimination of organic pollutants from wastewaters under visible-light irradiation is a venerable challenge in the fields of environmental and material science. In this work, we present a facile eco-friendly method to fabricate novel Cu2SnS3 flowers/RGO (Cu2SnS3/RGO) nanocomposites via a solvothermal method using L-cysteine as a sulphur source and linker. The crystal structure, morphology, purity, spectroscopic, and charge carrier separation properties of the synthesized samples were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission-scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), and X-ray energy-dispersive spectroscopy (EDS), Raman spectroscopy, UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and electrochemical impedance spectroscopy (EIS). The photocatalytic performance of the Cu2SnS3/RGO nanocomposites was evaluated by photocatalytic decolorization of eosin under visible-light irradiation. Results showed that the Cu2SnS3/RGO (3%) nanocomposite exhibits enhanced photocatalytic activity compared with the pure Cu2SnS3. The improved photocatalytic activity of the nanocomposite was mainly attributed to the formation of well-defined interface between Cu2SnS3 and graphene sheets, which greatly enhance the charge carrier separation efficiency in the Cu2SnS3 semiconductor.

Heteroarchitectured Ag–Bi2O3–ZnO was synthesized through a simple, cost effective, template free photodeposition-hydrothermal method. This composite material represents a prospective new class of novel catalysts wherein the improved light absorption behavior of a metal doped coupled oxide, Ag–Bi2O3–ZnO is anticipated to enhance with the observed benefits of a coupled system of Bi2O3–ZnO. Characterization of Ag–Bi2O3–ZnO revealed interesting optical and morphological characteristics. XRD patterns indicated that well-crystallized α-Bi2O3 was formed on the hexagonal wurtzite phase of ZnO along with Ag in the process. The HR-SEM images revealed the formation of organized intercrossed sheets and peanut shell like structure, which were composed of nanosheets and nanoparticles respectively. Elemental color mapping confirms the homogeneity of Zn, O, Ag and Bi in the catalyst. Ag–Bi2O3–ZnO has enhanced absorption in the UV and visible region when compared to Bi2O3 and ZnO. This catalyst exhibited enhanced photocatalytic activity for the degradation of Acid Red 1 (AR 1), Evens Blue (EB) and Acid Violet 7 (AV 7) under natural sunlight far exceeding those of the Bi2O3, Ag–ZnO, Ag–Bi2O3 and ZnO systems at neutral pH. Ag–Bi2O3–ZnO was found to be stable and reusable without appreciable loss of photocatalytic activity for up to five runs. Ag–Bi2O3–ZnO shows enhanced electrochemical methanol oxidation when compared to Ag–Bi2O3, Bi2O3–ZnO, Ag–ZnO and ZnO. Enhancement in methanol oxidation current demonstrates its high potential as an anode catalyst in direct methanol fuel cells.

ZnO–Eu2O3 nanocomposite was fabricated by a simple hydrothermal route. This material forms a potential class of photocatalysts in which the increased absorption behaviour in ZnO–Eu2O3 is expected to couple with the existing characteristics of Eu2O3 and ZnO materials. ZnO–Eu2O3 was characterized using surface analytical (SEM, EDS, HR-TEM, AFM, XRD) and spectroscopic techniques (XPS, DRS,PL). From the XRD patterns, formation of well-crystallized cubic Eu2O3 and hexagonal wurtzite phase of ZnO were inferred. Presence of nanoflake like structure with hexagonal ZnO and cubical Eu2O3 is shown by SEM pictures. ZnO–Eu2O3 possesses higher UV and visible absorption than Eu2O3 and ZnO. ZnO–Eu2O3 produces larger methanol oxidation current indicating its anodic catalytic efficiency in direct methanol fuel cells (DMFCs). This reveals higher electrocatalytic activity of ZnO–Eu2O3 than ZnO. It is observed that at −1.6 V, cathodic current density (ipc) of ZnO–Eu2O3 (−103.17 mA cm−2) for Hydrogen evolution reaction (HER) is more than five times of ZnO (−18.19 mA cm−2) and the hydrogen evolved with ZnO–Eu2O3is 15.6 mL, which is higher than that of ZnO (6.8 mL). This indicates the superior catalytic property of ZnO–Eu2O3 in water splitting. This catalyst exhibited higher catalytic activity of 99.2% in the photodegradation of Rhodamine B (Rh-B) with natural sunlight in 75 min under neutral pH, whereas Eu2O3 and ZnO produced 60 and 82% degradations in the same time. Degradation quantum efficiency by ZnO–Eu2O3 is larger than ZnO and Eu2O3. ZnO–Eu2O3 was stable and reusable. The multifunctionality of this catalyst makes it suitable for energy and environmental applications.

A novel eco-friendly and biocompatible method has been used with the help of Solanum surattense aqueous leaves extract to synthesis silver nanoparticles (AgNPs). The cost-effective green synthesis route has been given much care to ensure an environmentally friendly and straightforward approach, as it is most demanded in the biomedical industry. The proposed novel synthesis method offers additional compensations over other synthesizing approaches. Different analytical systems such as UV–vis, IR, XRD, DLS, SEM, EDAX, XPS, and TEM characterization techniques were used to understand the quality of the green synthesized nanoparticles for biomedical applications. The surface plasmon resonance peak of green synthesized silver nanoparticles at 446 nm was observed by UV absorbance spectral analysis. The XRD, SEM, and TEM analysis using to study the crystal structure, particle size, and surface morphology of the AgNPs. The results confirmed the synthesized spherical shape silver nanoparticles were crystallized in a face-centered cubic structure. The zeta potential measurement was used to authorize the excellent stability of AgNPs employing the dynamic light scattering method. FTIR spectral study confirmed that phytocompound participate in the bioreduction as well as stabilization of biosynthesized AgNPs by Solanum surattense. Also, the phytochemical content acts as the capping agent on surface AgNPs. The synthesized silver nanoparticles are subjected to antibacterial activity against both gram-positive and negative pathogenic bacteria for finding suitability in biocompatible applications. Also, the cytotoxicity of AgNPs was studied against the human breast cancer cell line and compared with one of the commercially available cancer drugs. Also, we have shown that the prepared AgNPs could serve as an excellent photocatalyst for degrading the Rhodamine B (RhB) dye and Acid Violet 7 (AV 7) dye under direct sunlight radiation.

Rutile TiO

Development of coupled semiconductor oxides makes a significant advancement in catalytic functional materials. In this article, we report the preparation of nanobundle-shaped BiVO4–ZnO photocatalyst by a simple hydrothermal process followed by thermal decomposition. The photocatalyst was characterized by X-ray powder diffraction (XRD), high-resolution scanning electron microscopy (HR-SEM), field emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL), and UV–vis diffuse reflectance spectroscopy (DRS). The XRD pattern confirmed formation of monoclinic scheelite BiVO4 and the hexagonal wurtzite structure of ZnO. HR-SEM images show nanobundle-like structure, and the size of the nanospheres ranges from 20 to 40 nm. BiVO4–ZnO has increased absorption in the UV and visible region when compared to ZnO. The cata...

Coupled semiconductor oxide nanomaterial Pr6O11–ZnO was fabricated by a simple hydrothermal method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), elemental color mapping, high resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy and BET surface area measurements. XRD analysis reveals that the as synthesized product has face-centered cubic phase of Pr6O11 and hexagonal wurtzite phase of ZnO. FE-SEM images of Pr6O11–ZnO show the nanochain like structures and Pr6O11 nanoparticles were homogeneously dispersed on the ZnO surface. The XPS analysis shows the presence of Zn, O and Pr elements and their oxidation states. Pr6O11–ZnO has increased absorption in the UV as well as visible region. The photocatalytic activity toward degradation of Acid Violet 7 (AV 7) under natural sunlight was investigated. Pr6O11–ZnO exhibits higher photocatalytic activity when compared to pure ZnO and Pr6O11 particles. Pr6O11–ZnO is more advantageous in toxic azodye degradation because of its reusability and higher efficiency at the neutral pH 7. Hydrophobicity of Pr6O11–ZnO has been evaluated using contact angle measurements. Pr6O11–ZnO modified TEOS coated substrates show significant hydrophobic properties. Pr6O11–ZnO exhibits high DC and photoconductivity, which make it useful for soliton wave communication and solar cell applications. Our results provide some new insights on the performance of a solar active photocatalysts, self cleaning and highly conductive materials.

Strontium fluoride-loaded titanium dioxide (SrF2-TiO2) was successfully synthesized by a sol–gel method and characterized by Fourier transform infrared and diffuse reflectance spectroscopies, scanning electron and transmission electron microscopies, X-ray diffractometry, cyclic voltammetry and Braunauer–Emmer–Teller surface area measurements. SrF2-TiO2 is found to be more efficient than bare TiO2 in the degradation of Reactive Yellow 84 (RY 84) under solar light at pH 5. SrF2 loading shifts the absorption edge to visible region resulting in the increase of solar photocatalytic activity. The effects of operational parameters such as the amount of photocatalyst, dye concentration, initial pH on photomineralization by SrF2-TiO2 have been analyzed. The mineralization of RY 84 has been confirmed by chemical oxygen demand (COD) measurements. Mechanism of dye degradation by SrF2-TiO2 is proposed on the basis of hole trapping property of SrF2. The catalyst is found to be stable and reusable. Reusability under solar light makes this process more economical for treatment of industrial effluent.

Development of bimetallic semiconductor oxides with synergistic functions makes a significant advancement in catalytic technologies. This study addresses the preparation of a codoped bimetallic Cd-Ag-ZnO photocatalyst by solvothermal process and its characterization by x-ray diffraction (XRD), high-resolution scanning electron microscopy (HR-SEM), UV-Vis diffuse reflectance spectroscopy (DRS), energy dispersive spectroscopy (EDS), and photoluminescence spectroscopy (PL). XRD and EDS reveal the presence of Cd and Ag in the catalyst. HR-SEM images show plate-like structure of ZnO and the clusters of Cd and Ag on the surface ZnO. Cd-Ag-ZnO has increased absorption in the UV region. This bimetalic photocatalyst shows higher photocatalytic activity for the degradation of Acid Black 1 (AB 1) and Acid Violet 7 (AV 7) under UV light (365 nm) than pure ZnO and commercial TiO2-P25. Cd-Ag-ZnO was found to be stable and reusable without appreciable loss of catalytic activity up to three runs.

A new nitrogen precursor, hydrazine hydrate was used in the synthesis of nano-sized, N-doped TiO2 photocatalyst by a simple wet impregnation method. This photocatalyst was characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), High resolution transmission electron microscope (HR-TEM), UV–vis diffuses reflectance spectra (DRS), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). XRD patterns show that the crystal structure of N-TiO2 resembles anatase phase of TiO2. The UV–vis spectra indicate an increase in absorption of visible light when compared to TiO2. Furthermore XPS analysis reveals the presence of the N atom as O–Ti–N linkage substituting the O atom in the TiO2 lattice and this causes a decrease in oxygen vacancies. N-TiO2 nanoparticles were used as a green and recyclable heterogeneous photocatalyst for rapid and efficient reductive cleavage of azoxybenzene into their corresponding amines or 2-phenylindazoles with methanol at room temperature under N2 atmosphere. Azoxybenzenes in neat methanol afforded anilines, while in aqueous methanol (20% water–80% methanol) they formed corresponding 2-phenyl indazoles. In both reductive cleavages, nano N-TiO2 is more effective than prepared TiO2, showing that the nitrogen doping could be an excellent choice to improve the photoactivity of TiO2.

Rutile TiO2 are widely used for applications of coatings, cosmetics, photoelectric devices and so on. However, effective control of well-defined morphology, size and composition of rutile TiO2 nanoparticles from agglomeration has always been a challenge. A new synthesis strategy was proposed to prepare rutile TiO2 with controllable morphology varied from flower-like structures to single-separated nanorods. The β-FeOOH nanoparticles were generated by the hydrolysis of FeCl3 solution and could prevent the aggregation of TiO2 nanocrystals at early stages of the reaction; thus, could control the morphology of rutile nanoparticles. The morphology of rutile TiO2 nanoparticles could be controllably regulated from flower-like structures to individually separated nanorods. Meanwhile, the preformed β-FeOOH also played a role of dopant. Fe ions were substitutionally doped into the bulk lattice of TiO2 nanocrystals and reduced the bandgap, which extended the solar radiation absorption range of rutile TiO2. The prepared TiO2 may be suitable for novel UV-blue light shielding agents and many other applications in photoelectric devices, photocatalysis, and so on due to its small size, unprecedented discrete rod-like structure and unique UV-vis light permeability.

The title photocatalyst is hydrothermally synthesized from an aqueous suspension containing Zn(NO3)2, Pr6O11, and oxalic acid (autoclave, 120 °C, 48 h) followed by calcination at 450 °C for 4 h.

This article reports on recent developments in heterogeneous AOP processes such as photocatalysis, Fenton-like process and catalytic ozonation. The principle, mechanism, and influence of experimental conditions on the degradation of pollutants in heterogeneous catalytic ozonation and the photocatalytic process were discussed. Introducing solid catalysts substantially increased the efficiency of the ozonation process by producing hydroxyl radicals in the degradation process. The different types of catalyst, catalyst dosage, solution pH, ozone flow rate, water matrix and catalytic reusability and stability are reported on here. The list of various semiconductor materials used as photocatalysts, their light absorption properties, various light sources and surface properties such as surface area, pore size and pore volume as a factor in the photocatalytic degradation of various pollutants are discussed. The review article also discussed the pollutants degraded using these three processes.