An original, facile way based on a non-aqueous sol-gel solvothermal process has been developed to synthesize 2D tungsten trioxide (WO3) nanoplatelets in one pot. The reaction between Tungstic acid (H2WO4) and 1-hexanol was a simple process, which resulted in the formation of highly crystalline metal oxide based on WO3 with an average size ranging between 30 and 50 nm, and with a correspondingly high surface area. The structural, morphological, functional group, optical qualities of the materials and the properties of the adsorption surfaces were all examined , and the degree of surface hydroxyls ( -OH groups) has been examined. The products of the reaction were characterized by X-ray Powder Diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy, Nitrogen adsorption ,and pore-size distribution Brunauer-Emmett-Teller, Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance Spectroscopy techniques. which indicated the formation of di-hexyl ether as a result of the solvothermal reaction.The optical absorption, measured using UV-Vis Diffuse Reflectance Spectroscopy, revealed a narrow bandgap (Eg = 2.18 and 2.48 eV for WO3-24 and WO3-48, respectively) compared to that of for bulk WO3 (2.7 eV), attributable to oxygen vacancies. Upon increasing dwell time from 24 to 48 h, a blue-shift was observed, highlighting a quantum size effect. The as-prepared WO3 nanoplatelets displayed excellent photocatalytic performance for degrading Rhodamine B under visible light-emitting diode light with up 99 % degradation rate was achieved in 120 min. Thus, the enhanced Rhodamine B photodegradation in the presence WO3-24 along with H2O2 was assigned to the reactive oxygen species (ROS) such as • OH and RhB *+ , involving in the strong synergistic effect between WO3 and H2O2, effectively separating of photocarriers and, as a consequence, boosting the photocatalytic efficiency.

Photocatalytic production of H2 from the decomposition of water has attracted increased attention, as the environmental damages caused by the rapid evolution of industry are threatening the development of human society. This energy production is considered a green and eco-friendly resource. It has the potential to replace the carbon component of fuelling the society; on the other hand allows for the limitation of greenhouse gas emissions, thereby mitigating the worsening of climate change. While titanium dioxide is widely used in the photocatalytic field, its yield is still low due to the fast recombination of the photo-generated charge carriers. Graphitic carbon nitride (g-C3N4) possessing high thermal and chemical stability, non-toxicity and low band gap energy is a promising candidate for photocatalytic applications. In this study the exfoliation of the bulk g-C3N4 made with melamine was synthesised via a chemical approach using nitric acid at room temperature, in order to get prolonged carrier lifetime. Moreover the surface of bulk g-C3N4 made with melamine and urea and the exfoliated g-C3N4 made with melamine was modified with graphene (0.5 wt% and 1 wt%). Hydrogen generation from methanol/water mix proved that only hydrogen was produced in the unmodified bulk and exfoliated g-C3N4 , while H2, CH4 and CO have been generated in the modified specimens with graphene. This was assigned to the increased spatial charge carrier separation conducted by graphene.

An original, facile way based on a non-aqueous sol–gel solvothermal process has been developed to synthesize 2D tungsten trioxide (WO3) nanoplatelets in one pot. The reaction between Tungstic acid (H2WO4) and 1-hexanol was a simple process, which resulted in the formation of highly crystalline metal oxide based on WO3 with an average size ranging between 30 and 50 nm, and with a correspondingly high surface area. The structural, morphological, functional group, optical qualities of the materials and the properties of the adsorption surfaces were all examined, and the degree of surface hydroxyls (– OH groups) has been examined. The products of the reaction were characterized by X-ray Powder Diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy, Nitrogen adsorption, and pore-size distribution Brunauer-Emmett-Teller, Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance Spectroscopy techniques. which indicated the formation of di-hexyl ether as a result of the solvothermal reaction. The optical absorption, measured using UV–Vis Diffuse Reflectance Spectroscopy, revealed a narrow bandgap (Eg = 2.18 and 2.48 eV for WO3-24 and WO3-48, respectively) compared to that of for bulk WO3 (2.7 eV), attributable to oxygen vacancies. Upon increasing dwell time from 24 to 48 h, a blue-shift was observed, highlighting a quantum size effect. The as-prepared WO3 nanoplatelets displayed excellent photocatalytic performance for degrading Rhodamine B under visible light-emitting diode light with up 99 % degradation rate was achieved in 120 min. Thus, the enhanced Rhodamine B photodegradation in the presence WO3-24 along with H2O2 was assigned to the reactive oxygen species (ROS) such as ; OH and RhB *+ , involving in the strong synergistic effect between WO3 and H2O2, effectively separating of photocarriers and, as a consequence, boosting the photocatalytic efficiency.

Graphitic carbon nitride (g-C3N4) possessing high thermal and chemical stability, non-toxicity, facile synthesis, and low band gap energy is a promising candidate for photocatalytic applications. In this study, bulk and...

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In today's society, air and water pollution, as well as clean energy, have become major concerns. Photocatalysis could be one of the ways used to address this new set of problems. Photocatalysis is a type of advanced oxidation method that involves light to activate a semiconductor. The semiconductor materials most likely to generate these reactions are titanium dioxide-based. However, TiO2 has its drawbacks, as light absorption limited to the UVA region of the solar radiation due to its wide band-gap (~3.2 eV), and a high rate of photogenerated electron-hole recombination in the photocatalyst. To address those problems, the sol-gel process was adopted for the synthesis of TiO2 nanoparticles, and TiO2 heterojunction with WO3 was carried out to decrease the rate of electron-hole pair recombination and enhance photocatalytic properties. In addition, graphene nanoplatelets were introduced to the TiO2/WO3 system to aid the transport and separation of photogenerated exciton. In this work, various parameters affecting the photocatalytic activity of the synthesized materials were investigated, including the ratio of WO3 to TiO2, the introduction of graphene, and the nature of the photocatalytic application (degradation of gaseous benzene and generation of H2). The structural and optical characteristics, as well as the properties of the adsorption surfaces, were all investigated. It was found that for materials containing more than 10 mol % of WO3, the addition of graphene in to the TiO2/WO3 system appears to boost photocatalytic activity for H2 generation under UV light compared to the TiO2/WO3 system, suggesting the existence of an optimal proportion allowing a greater photocatalytic activity.

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