采用高温热剥离和溶剂热过程分别还原氧化石墨和氧化石墨制备出石墨烯，进一步使用所合成的石墨烯与P25通过一步水热过程合成出石墨烯/P25复合材料。样品的光催化活性通过可见光下降解罗丹明B进行评测，其中P25和热剥离还原得到的石墨烯复合比P25和溶剂热还原的石墨烯复合显示出更优异的光催化活性，这是由于热剥离还原的石墨烯具有更高的还原度和更强的电子—空穴分离效率所致。进一步在不同温度下通过热剥离法制备了还原石墨烯，探讨的石墨烯/P25复合材料的光催化活性。较高的剥离温度有利于石墨烯还原程度的改善，导致光催化活性的提高。
Two kinds of graphene prepared by a high-temperature exfoliation and a solvothermal method were used as supports of a TiO2 catalyst (P25) from Degussa, Inc to prepare TiO2/graphene composites. The photocatalytic activities of the composites were evaluated by their degradation of Rhodamine B in aqueous solutions under visible light. Results indicate that the composites prepared by high-temperature exfoliation have much higher photocatalytic activities than those produced by the solvothermal method or the un-supported P25. Both the adsorption capacity of Rhodamine B on the composites and their light absorption characteristics are inde-pendent of the kind of graphene used. The activity increases with exfoliation temperature and reduction degree of the graphene re-gardless of the methods and conditions used, indicating that a high degree of reduction of graphene can inhibit the recombination of electron-hole pairs generated by light irradiation by increasing electron transfer from TiO2 to the graphene layer.
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