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采用微乳法制备了n-p型CeO_2/BiOBr异质结,其中十六烷基三甲基溴化铵(CTAB)既作为Br源,又作为“桥”使CTA~+修饰在CeO_2表面形成了稳定的油包水微乳体系.利用XRD、SEM、HRTEM、UV-Vis DRS、BET、XPS等对样品进行结构、形貌和光学性质进行表征,并对复合光催化剂进行了可见光下降解甲基橙(MO)的光催化活性研究.考察了不同煅烧温度对合成CeO_2/BiOBr的影响.结果表明:CeO_2/BiOBr异质结相比于单体CeO_2和BiOBr来说,它的光响应范围大大增加,在可见光下降解MO具有更高的光催化活性.450℃下煅烧可使MO达到最佳的降解率,而高温则会使催化剂发生烧结.机理研究表明,在CeO_2与BiOBr复合体中,使有机物矿化的主要为CeO_2价带上的光生空穴.CeO_2/BiOBr催化活性增强主要是由于在CeO_2与BiOBr之间形成了n-p型的异质结.
Np CeO_2 / BiOBr heterojunction was prepared by microemulsion method, in which cetyltrimethylammonium bromide (CTAB) was used as Br source and CTA ~ + modified to form on the surface of CeO_2 The stable water-in-oil microemulsion system was characterized by XRD, SEM, HRTEM, UV-Vis DRS, BET, XPS and so on.The structure, morphology and optical properties of the sample were characterized and the photocatalytic degradation of methyl orange (MO). The effect of calcination temperature on the synthesis of CeO_2 / BiOBr was investigated. The results show that the CeO_2 / BiOBr heterojunction has a much higher photoresponse range than CeO_2 and BiOBr, Degradation of MO in visible light has higher photocatalytic activity.At 450 ℃ calcination can MO achieve the best degradation rate, while the high temperature will make the catalyst sintering.Mechanism studies show that, in the CeO 2 and BiOBr complex, the organic matter The photogenerated holes on the valence band of CeO_2 are mainly mineralized.The enhancement of the catalytic activity of CeO_2 / BiOBr is mainly due to the formation of np-type heterojunction between CeO_2 and BiOBr.