Preparation Of Graphene/TiO₂ Composite Material And Its Photocatalytic Hydrogen Pruduction

In 1972,the Japanese scientists Fushiji and Honda found that the H₂ can be obtained from splitting water by TiO₂ semiconductor materials under the condition of UV-irradiation.The increasing of energy crisis promotes to exploration for new forms of energy as substitutes for fossil fuels.Photocatalytic hydrogen production is based on catalyst utilizing the solar energy splitting water for H₂ evolution.Due to its great research significance makes the photocatalytic production hydrogen become one of promising candidates for substitutes for fossil fuels.In recently years,due to its excellent photocatalytic production hydrogen performance,TiO₂ has became the research hotspot in this field.Traditional TiO₂ as catalyst of photocatalytic production hydrogen can not satisfy the increasing demand of hydrogen.The photocatalytic production hydrogen performance has been difficult to meet the demand,exploring higher catalytic performance of TiO₂-based semiconductor materials is imminent.The poor electrical conductivity of TiO₂ limits its development in industrialization process.The band gap of TiO₂ is 3.2 eV,which only have a response to uv-light,and lead to excessive carrier.When the TiO₂ size is too large and hole inside the material composition.Graphene was used as catalytic cracking light water an important part of the hydrogen production system due to its excellent photoelectric properties.This paper based on the research progress of TiO₂ and graphene,combine both effective and preparation of a porous two-dimensional lamellar structure composed of particles nanocomposites.The unique structure will reduce the rate of hole with carrier compound,increase the rate of hydrogen production and improve the quantum utilization.In this paper,the G/TiO₂ was synthesized by an one-step moderate water bath.Then the precursors have been annealed in air in different time to archieve a series of different content of carbon composites.The final products have been characterized analysis by scanning electron microscope?SEM?,transmission electron microscopy?TEM?,X-ray diffraction?XRD?,specific surface area test,thermogravimetric analysis and uv-vis and ir test.The photocatalytic mechanism of TiO₂/G has been discussed.G/TiO₂ precursors annealed at 500?for 5 h under air condition shows the best photocatalytic production hydrogen performance among the all samples,corresponding to the optimal proportion of particle size and the content of graphene in the composites.The large pore width,high specific surface area,the large under uv-absorptivity,result the hydrogen production rate of 0.72 mmol·h^-1.To the best of our knowledge,there are no reports for such high production rate for TiO₂-base catalysts under the same test condition for photocatalytic production hydrogen.