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XRM2010. AIP Conf Proc 2010, 1365:215–218. Competing interests The authors declare that they have no competing interests. AZD2281 in vivo Authors’ contributions The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript.”
“Background Global warming caused by large-scale emission of carbon dioxide (CO2) in the atmosphere and the depletion of fossil fuels are two critical issues to be addressed in the near future [1].

Great effort has been made to reduce CO2 emissions. Technologies involving carbon capture and geological sequestration have accelerated in R788 the past decade [2]. Unfortunately, most of the associated processes require extraneous energy input, which may result in the net growth of CO2 emission. Furthermore, there are many uncertainties with the long-term underground storage of CO2. In this regard, the photocatalytic reduction of CO2 to produce hydrocarbon fuels such as methane (CH4) is deemed as an attractive and viable approach in reducing CO2 emissions and resolving the energy crisis [3, 4]. Many types of semiconductor photocatalysts, such as TiO2[5], ZrO2[6], CdS [7], and combinations thereof [8] have been widely studied for this purpose. By far the most researched photocatalytic material Cell press is anatase TiO2 because of its long-term thermodynamic stability,

strong oxidizing power, low cost, and relative nontoxicity [9, 10]. However, the rapid recombination of electrons and holes is one of the main reasons for the low photocatalytic efficiency of TiO2. Moreover, its wide band gap of 3.2 eV confines its application to the ultraviolet (UV) region, which makes up only a small fraction (≈5%) of the total solar spectrum reaching the earth’s surface [11]. In order to utilize irradiation from sunlight or from artificial room light sources, the development of visible-light-active TiO2 is necessary. In the past few years, carbon-based TiO2 photocatalysts have attracted cosmic interest for improved photocatalytic performance [12, 13]. Graphene, in particular, has been regarded as an extremely attractive component for the preparation of composite materials [14, 15]. In addition to its large theoretical specific surface area, graphene has an extensive two-dimensional π-π conjugation structure, which endows it with excellent conductivity of electrons [16]. Carriers in pristine graphene sheets have been reported to behave as massless Dirac fermions [17].