UV-Visible ار راد ن .د TiO2 ( تیفرظ راون مان هب نورتکلا یاراد یژرنا زارت لماش VB و ) رگید زارت ی یژرنا اب ( ییاناسر راون مان هب نورتکلا زا یلاخ و رتلااب VB یم ) .دشاب ت ود نیا نیب یژرنا توافت یژرنا فاکش زار ، پگ دناب هدیمان یم .دوش هک ینامز زا نورتکلا لاقتنا VB هب VB یم ماجنا دریگ ، TiO2 اب ودح یژرنا بذج د ev 2 / 3 ، نورتکلا تفج کی دیلوت یم هرفح .دیامن و نورتکلا هرفح ی نا اب هدش دیلوت یم کرتشم حطس هب لاقت ثعاب دناوت شنکاو ماجنا اه یی ددرگ . TiO2 دربراک ،دراد یدایز یاه هلمج زا یم ناوت اوه یگدولآ هیفصت یارب (CO2) و بآ و ... نآ زا هدافتسا درک .

Advanced Nanoarchitectures for Solar Photocatalytic Applications

Transparent conductors as solar energy materials: A panoramic review

A series of titanium dioxide and graphene sheets (GSs) composites were synthesized with a sol–gel method using tetrabutyl titanate and graphite oxide (GO) as the starting materials. The obtained TiO2/GSs photocatalysts are characterized by X-ray diffraction, N2 adsorption analysis, Raman spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy. The photocatalytic activity of the as-prepared samples was evaluated by hydrogen evolution from water photo-splitting under UV-vis illumination. The influence of GSs content and calcinations atmosphere on the photocatalytic activity was also investigated. The results show that both GSs content and the calcinations atmosphere can affect the photocatalytic activity of the obtained composites.

Graphene/TiO2 nanocomposites: synthesis, characterization and application in hydrogen evolution from water photocatalytic splitting

Engineering photocatalytic materials for renewable energy generation and environmental decontamination has always been a very exciting prospect to counter the global energy demands and pollution challenges. Graphitic carbon nitride (g-C 3 N 4 ), a polymeric, metal-free semiconductor with a mild band gap (2.7 eV) has become hot-spot in various scientific exploits such as environmental pollution mitigation, energy generation and storage, organic synthesis, sensors, etc. These applications exploit the interesting properties of g-C 3 N 4 such as good visible light absorption, graphene-like structure, good thermal and chemical stability and photocatalytic properties. In this review we begin with an overview of the fundamental aspects of photocatalysis as a pollution remediation strategy. This is followed by an introduction to graphitic carbon nitride as a photocatalyst, preparation strategies and its properties. Subsequently, a comprehensive and critical discussion of the various most recent developments towards enhancing the visible light photocatalytic properties of g-C 3 N 4 for pollution alleviation, selected results and important photocatalytic degradation mechanisms, is given. Summary remarks and future perspective conclude the review.

Graphitic carbon nitride (g-C3N4) nanocomposites: A new and exciting generation of visible light driven photocatalysts for environmental pollution remediation

Titanium dioxide represents an effective photocatalyst for water and air purification and for self-cleaning surfaces. Additionally, it can be used as antibacterial agent because of strong oxidation activity and superhydrophilicity. TiO 2 shows relatively high reactivity and chemical stability under ultraviolet light (λ 400 nm) should allow the main part of the solar spectrum, even under poor illumination of interior lighting, to be used. Visible light-activated TiO 2 could be prepared by metal-ion implantation, reducing of TiO 2 , non-metal doping or sensitizing of TiO 2 with dyes. This paper reviews preparation methods of doped-TiO 2 with metallic and nonmetallic species, including various types of dopants and doping methods currently available. The mechanism of heterogeneous photocatalysis in the presence of TiO 2 is also discussed.

Doped-TiO2: A Review

Ultraviolet- and visible-light-responsive titania-based photocatalysts were synthesized and employed in the photocatalytic oxidation of NOx. Sol–gel processes using tetrabutyl orthotitanate and ethanol under acid catalyzed condition and controlled calcination were performed to synthesize titanium dioxide with a mixed crystal lattice of anatase, brookite and rutile phases. The TiO2 prepared under calcination at 200 °C exhibited high photocatalytic activity for degradation of NOx under both ultraviolet (UV) and visible-light illumination. The experimental results showed that up to 70% removal of NOx could be obtained in a continuous flow type reaction system under irradiation with visible light. The calcination temperature has an important influence on the particle size and lattice structure of TiO2. It is also found that the peculiar mixed-phase structure of TiO2, evidenced from Raman, x-ray diffractometry (XRD), and UV–vis spectroscopy, was inferred to be an important factor for visible-light absorption and NOx removal activity under a wide range of visible-light illumination.

http://iopscience.iop.org/article/10.1088/0957-4484/17/10/009/pdf

Visible-light-responsive nano-TiO2 with mixed crystal lattice and its photocatalytic activity

Photoactivities of the carbon-containing nano-structured titanium dioxide (TiO 2 ) prepared using a modified sol–gel method as visible-light-responsive photocatalysts were studied. This research aimed to compare four carbon-containing TiO 2 samples, prepared in different conditions, with a commercial nano-structured TiO 2 powders. The prepared titanium dioxide powders were analyzed using Raman spectroscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy. It is found carbon-containing TiO 2 nanoparticles prepared under calcinations at 200 °C exhibited high photocatalytic activity for decoloring of methylene blue and the removal of nitrogen monoxide under both ultraviolet and visible-light illumination. The calcination temperature and incorporated carbons affect the particle size and lattice structure of TiO 2 , and hence the photoactivities. The superior photocatalytic effects were attributed to the carbon-containing mixed anatase and rutile phase in the crystal structure of the TiO 2 .

Photoactivities of the visible-light-activated mixed-phase carbon-containing titanium dioxide: The effect of carbon incorporation

Pure and carbon-doped amorphous titania films were prepared in an argon–oxygen plasma by reactive sputtering of a titanium metal target and co-sputtering of a Ti and a graphite target, respectively. The as-deposited films were subsequently annealed in vacuum and in air. The influence of the annealing atmosphere and temperature on the composition, phase transformation and crystallinity of the films was systematically studied. The results indicate that carbon incorporated in titania and an oxygen deficient environment both facilitate the formation of oxygen vacancies in titania which favors the phase transformation to rutile during annealing at low temperatures. A mechanism is proposed to explain why carbon incorporation and oxygen defects in titania favors the formation of rutile during annealing.

Po-Wen Chou

Papers

Visible-light-responsive nano-TiO2 with mixed crystal lattice and its photocatalytic activity

Photoactivities of the visible-light-activated mixed-phase carbon-containing titanium dioxide: The effect of carbon incorporation

Effect of carbon and oxygen on phase transformation of titania films during annealing