Abstract
Background: Titanium dioxide (TiO2) powders with visible-light photoactivities are in great demand for application in solar cells and solar photocatalysis. Although pure TiO2 is active only under ultraviolet light, its band gap can be narrowed down to the visible-light by impurity doping and creation of surface defects. Visible-light active anatse TiO2 powder attracts a great research interest because of its higher efficiency observed in water splitting, hydrogen generation and solar photocatalysis.
Methods: Nitrogen doped TiO2-C composite nanoparticles were synthesized in large scale by a simple and efficient chemical reaction using oleic acid and titanium tetra-isopropoxide as the precursors. The composition of the powder was analyzed by X-ray photoelectron spectroscopy, the structure was studied with X-ray diffraction and transmission electron microscopy and the optical property was studied by uv-vis absorption. The visible photocatalytic activity of black TiO2 powder was investigated by studying the photobleaching of methylene blue under solar irradiation. The effect of surface concentration of the carbon and nitrogen on the visible photocatalytic efficiency of the black-TiO2 was studied and reported. White TiO2 powder without surface carbon was also synthesized and all the properties of the above was compare with that of the black TiO2 powder.
Results: Black TiO2 was purely anatase whereas white TiO2 had mixed phase character with 68% anatase and 32% rutile. Compared to white TiO2, black TiO2 could absorb more visible light. Unlike white TiO2, Black TiO2 is an efficient solar photocatalyst responsible for the photodegradation of 52 µM aqueous solution of MB with a first order rate constant, k = 0.02 min-1. The photocatalytic activity of black-TiO2 strongly depended on the surface carbon concentration. The photocatalytic activity of black-TiO2 increases with increased carbon content. When the surface concentration exceeded 28%, the catalytic activity decreased presumably due to slower rate of charge transfer onto the TiO2 nanoparticle surface. No such systematic change in the photocatalytic activity of black-TiO2 was observed with change in its N content.
Conclusion: The visible-light active TiO2-C nanocomposite powder is very important for environmental applications. Environmental remedies such as water purification, prevention of indoor air pollution and outdoor self-cleaning process can be taken up with a low cost but highly efficient black TiO2-C photocatalyst.
Keywords: Black titanium dioxide, raman spectroscopy, transmission electron microscopy, visible photocatalysis.
Graphical Abstract
Call for Papers in Thematic Issues
Role of nanomaterials in fabrication of coatings, Machining and Joining
The application of nanoscience has brought about a revolution in the field of mechanical engineering by providing novel materials, boosting manufacturing processes, and generating cutting-edge products. The purpose of this special issue is to investigate the enormous impact that nanoscience has had on mechanical engineering, with a particular emphasis on ...read more
Advanced Inorganic Nanocomposites and Their Emerging Applications
This special issue collection will highlight developments on the recent trends about the synthesis of metal oxides, nanoclusters, biomaterials, 2D nanomaterials, nanocrystals, nanocomposites, etc. and their applications in electrochemical systems, tissue regeneration, energy storage and harvesting, sensors, etc. The novelty of the methods in the chemical synthesis and their characterizations, ...read more
Applicability of Nanotechnology for Performance Enhancement of Clean Energy Technologies
Population growth, industrialization, and improvement in living quality would lead to further increase in energy demand in near future. Regarding the disadvantages of fossil fuels such as fluctuations in their price, high emissions of greenhouse gases and restriction of their sources, it is crucial to use and exploit alternative energy ...read more
Graphene and 2D Materials for Energy Storage and Conversion
This thematic issue will discuss the recent advances in graphene-based nanomaterials for different energy technologies. Graphene possesses a high surface area, and stable structure and exhibits many interesting electronic, optical, and mechanical properties due to its 2D crystal structure. Graphene is of both fundamental interest and suitable for a wide ...read more
Related Books
Nanoscale Field Effect Transistors: Emerging Applications
Nanoelectronics Devices: Design, Materials, and Applications Part II
Nanoelectronics Devices: Design, Materials, and Applications (Part I)
Role of Nanotechnology in Cancer Therapy
Synthesis and Applications of Semiconductor Nanostructures
Pathways to Green Nanomaterials: Plants as Raw Materials, Reducing Agents and Hosts
Applications of Nanomaterials in Medical Procedures and Treatments
Synthesis of Nanomaterials
Nanobiotechnology: Principles and Applications
Bio-Inspired Nanotechnology
27
2
1
1