| The energy crisis has become an important topic for the future development of mankind.With the increase of energy demand,traditional energy sources are gradually unable to meet the requirements of human production.Utilization of photocatalytic hydrogen production has directly convert solar energy to hydrogen energy,and providing stable energy supply supported by large-scale electrochemical energy storage facilities,are the effective ways to solve environmental pollution and energy crisis.In recent years,graphene has attracted much attention due to its excellent physical properties,such as high conductivity,heat conduction and large specific surface area.At present,a large number of literatures have reported that graphene modified semiconductor materials have been used in photocatalysis,battery and other fields to improve photocatalytic performance and electrochemical performance of batteries.In this paper,composite photoelectric chemical materials were constructed,in which graphene,as an optimized electron transport channel,could promote the separation of photogenerated electron-hole pairs in the process of photocatalytic hydrogen production,and could increase the battery capacity in the application of lithium battery materials.The main research work of this paper is as followed:First,graphene/TiO2 composites were prepared by sol-gel method using commercial graphene（GR（s））and titanium sol as raw materials.The effects of graphene content and calcined temperature on the hydrogen production activity had been studied.The photohydrolysis performance of 0.5%GR（s）/TiO2-300 was the best,and the hydrogen production rate reached to 27.6μmol h-11 g-1,which was about 3.2 times than that of TiO2.GR/TiO2 samples were prepared from graphene（GR）prepared by CVD method and titanium sol.The effect of graphene preparation method on the hydrogen production activity of photolysis water was investigated.The photohydrolysis rate of the GR/TiO2-300 sample was 415.8μmol h-11 g-1,which was 15 times than that of 0.5%GR（s）/TiO2-300.The number of graphene layers prepared by CVD method was small,which was benefit to overcome the light shielding effect and received a better light intensity absorption.The combination with TiO2 was benefit to get a narrow the band gap and expand its photoresponse range;it has high conductivity.It was better to the migration of photogenerated electrons and improved the separation efficiency of electrons and holes,then improved the photocatalytic performance.Secondly,commercial graphene/TiO2/Chlorella composites were prepared via sol-gel method.When the contents of graphene and Chlorella were 0.5 wt%and 1 wt%respectively,and the calcined temperature was 300oC,the photocatalytic activity of graphene/TiO2/Chlorella photocatalyst（GT-1C）showed the best photocatalytic performance.The hydrogen production rate was 93.4μmol h-11 g-1,which was about 3.4times than that of 0.5%GR（s）/TiO2-300.The improvement of photocatalytic activity with obtaining Chlorella can be attributed to the expanded light absorption,hybridization of organic matter with TiO2 and the doping of carbon.Carbon can also become the separation center of photogenerated electrons and holes.The photocatalytic performance of graphene prepared by CVD method/TiO2/Chlorella was better than that of commercial graphene/TiO2/chlorella,mainly due to the graphene prepared by CVD method has the advantages of few layers and high conductivity.Third,the hierarchical graphene/Zn3V3O8 composite was fabricated by a simple one-pot ethanol thermal reduction strategy.When used as the lithium-ion batteries of anode material,it exhibited high reversible capacities(1012 mAh g-1at 0.1 A g-1after 200cycles)and high rate stability（448 mAh g-11 at 4 A g-11 after 1000 cycles）.The outstanding performance can be attributed to the synergistic effect of the diverse structural virtues,effective interface and carbon network. |
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