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In 2 S 3 / branched TiO 2 nanorods (br-TiO 2) heterostructure was prepared by a simple route using three-step methods as a visible and solar light photocatalyst for water treatment applications. Structural properties have been carried out by X-ray diffraction and Raman spectroscopy. Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and atomic force microscopy has been used to determine the morphology and the surface roughness of samples. The In 2 S 3 / br-TiO 2 heterojunction confirm the presence of both structures of Rutile TiO 2 and cubic β-In 2 S 3. Optical results showed that the heterojunction exhibited increased absorption ability in the visible light, indicating an increased photoactivity for In 2 S 3 / br-TiO 2 in the visible light. Wettability studies reveal that In 2 S 3 / br-TiO 2 film is superhydrophilic with water contact angle of 0°. Photocatalytic activity of heterojunction In 2 S 3 / br-TiO 2 was assessed with remarkable degradability performance of 85% after 80 min under solar irradiation. The reusability test highlighted that the In 2 S 3 / br-TiO 2 still maintained high photocatalytic activity over five cycles. The photoelectrochemical activity was evaluated. The results showed the successful development of In 2 S 3 / br-TiO 2 heterostructure with better photoactivity properties. The In 2 S 3 / br-TiO 2 electrode achieved remarkably improved current density (0.59 mA.cm2 at 0.6 V vs Ag/AgCl) compared to br-TiO 2 and In 2 S 3. These results reveal that In 2 S 3 / br-TiO 2 thin films being excellent photoactivity along with its superhydrophilic nature which it is possesses great potential toward the development of newly synthesizable catalysts in the field of water purification. • br-TiO 2 , In 2 S 3 , In 2 S 3 / br-TiO 2 thin films were prepared by a cost-effective hydrothermal method and chemical bath deposition • Excellent light harvesting capabilities of In 2 S 3 br-TiO 2 heterostructure • In 2 S 3 / br-TiO 2 thin films show superhydrophilic character • High performance photocatalytic activity of heterostructure up to 85% after 80 min under solar irradiation. • The PEC performance of In 2 S 3 / br-TiO 2 is greatly improved compared to those of br-TiO 2 and In 2 S 3. [ABSTRACT FROM AUTHOR]

[Display omitted] • MoS 2 nanosheets were successfully deposited onto silicon nanowires (SiNWs) through hydrothermal process. • The MoS 2 /SiNWs heterostructure have been successfully prepared by combing hydrothermal and metal assisted chemical etching processes. • MoS 2 /SiNWs heterostructure exhibited an improvement of photocatalytic degradation of MB under visible light irradiation. Molybdenum disulfide (MoS 2) is weakly stacked by vander Waals force, and the interaction force between the layers of MoS 2 and Silicon is weak. Therefore, direct growth of homogeneous high quality MoS 2 films on silicon substrates stays challenging. Herein, for the first time, few layered MoS 2 nanosheetswere successfully deposited onto silicon nanowires (SiNWs) through hydrothermal process. First, as prepared MoS 2 /SiNWs heterostructure was characterized by using Raman spectroscopy, Scanning Electron Microscopy (SEM) and by means of the Energy-Dispersive X-ray spectroscopy (EDX). Second, the photocatalytic activity ofsynthesizedMoS 2 /SiNWs photocatalyst was systematically evaluated for the decoloration of methylene blue (MB) under visible light irradiation. It was found that MoS 2 /SiNWs heterostructure exhibited excellent photocatalytic activity against this dye compared with synthesized SiNWs films. Also, it was found that after irradiation during 180 min, the MoS 2 /SiNWs film exhibited the highest photocatalytic efficiency (90%), in comparison to SiNWs (62%). Finally, it is assumed that the photocatalytic activity improvement was attributed to visible light absorption improvement, the enhancement of the photogenerated electron-hole pair's separation efficiency. Moreover, thanks to the nanoflowers structure assembled by nanosheets with few layers, the specific surface area was increased offering more sites for MB pollutant adsorption. [ABSTRACT FROM AUTHOR]

Titanium dioxide nanorods arrays (NRAs) photoanodes have been grown by the hydrothermal method on FTO coated glass substrates for different hydrothermal reaction time. Synthesized TiO 2 NRAs films were compared in terms of their structural, optical and morphological properties. Their wettability and photoelectrochemical performances were also investigated. We found that the sample elaborated at 10 h has the best physical properties. SEM images show that the surface of the FTO substrate is uniformly covered by TiO 2 NRs with the optimum packing density. UV–vis-absorption measurements revealed that this sample exhibits good (excellent) light harvesting capabilities. The wettability tests revealed that this sample is more hydrophilic among all prepared samples. A strong correlation between morphological, optical and photoelectrochemical performance has been discussed. [ABSTRACT FROM AUTHOR]

Graphene is extremely sensitive to its surrounding environment. In fact, any modification on its surface, such as an adsorption of a molecule, can change its properties. The conductivity of graphene is a crucial parameter to be examined for potential graphene-based applications, especially biosensors. In this paper, we have investigated the effects of non-covalent functionalization based on π–π interaction, using 1-pyrenebutyric acid N-hydroxysuccinimide ester (PBASE), on the conductivity of graphene-based electrodes by electrochemical techniques. Graphene layers were obtained by chemical vapor deposition (CVD) and characterized by Raman spectroscopy, Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). The results demonstrate the synthesis of a high quality and continuous monolayer graphene with an I2D/IG ratio = 2.71 and ID = 0. After the functionalization of graphene-based electrode with PBASE, the electrochemical analyses confirmed a p-doping effect existence influencing the conductivity by increasing the charge transfer resistance Rct from 816.5 to 2213 Ω. Furthermore, increasing the concentration of PBASE from 5 mM to 10 mM did not affect the conductivity as the Rct did not change. Solvent adsorption was found to be the main cause of the decrease in conductivity during the functionalization process. This study highlights the effect of non-covalent π-π stacking of PBASE on graphene to tune the electrical properties of graphene through functionalization processes for a better performance for their use as biosensors. [ABSTRACT FROM AUTHOR]

Porous magnetite (Fe3O4) and hematite (α-Fe2O3) nanoparticles were prepared via the sol-gel auto-combustion method. The gels were prepared by reacting ferric nitrates (as oxidants) with starch (as fuel) at an elevated temperature of 200 °C. Different ratios (Φ) of ferric nitrates to starch were used for the synthesis (Φ = fuel/oxidant). The synthesized iron oxides were characterized by Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmet-Teller (BET) and vibrating sample magnetometer (VSM) analysis techniques. The crystal structure, morphology, and specific surface area of the iron oxide nanoparticles (Fe3O4 and α-Fe2O3) were found to be dependent on the starch content. The FT-IR, XRD and VSM analysis of the iron oxides for Φ = 0.3 and 0.7 confirmed the formation of the α-Fe2O3 core, whereas at Φ = 1, 1.7, and 2 showed that Fe3O4 cores were formed with the highest saturation magnetization of 60.36 emu/g at Φ = 1. The morphology of the Fe3O4 nanoparticles exhibited a quasi-spherical shape, while α-Fe2O3 nanoparticles appeared polygonal and formed clusters. The highest specific surface area was found to be 48 m² g-1 for Φ = 1.7 owing to the rapid thermal decomposition process. Type II and type III isotherms indicated mesoporous structures. [ABSTRACT FROM AUTHOR]