(1. 東華理工大學(xué) 核資源與環(huán)境國家重點(diǎn)實(shí)驗(yàn)室，南昌 330013；
2. 中國輻射防護(hù)研究院，太原 030006)
摘 要: 通過濕浸漬法制備了CuO/BiFeO3可見光響應(yīng)異質(zhì)結(jié)光催化劑，通過SEM、XRD、XPS、UV-Vis等分析手段對(duì)材料進(jìn)行表征，并在室溫下以氙燈為光源，探討CuO/BiFeO3異質(zhì)結(jié)復(fù)合催化劑光催化還原溶液中U(Ⅵ)的性能，并對(duì)光催化還原機(jī)理進(jìn)行了初步分析。結(jié)果表明，CuO顆粒呈球狀，表面光滑，為單斜晶型。BiFeO3由不規(guī)則的顆粒團(tuán)聚成層狀，為鈣鈦礦結(jié)構(gòu)。與純CuO和BiFeO3相比，含10% CuO的CuO/BiFeO3對(duì)U(Ⅵ)的光催化還原效果最好，其去除效率遠(yuǎn)高于純CuO和BiFeO3的；在可見光照射下催化反應(yīng)100min時(shí)，U(Ⅵ)的去除率達(dá)96%以上。該催化劑光催化活性的提升主要是由于在CuO和BiFeO3界面上形成的p-n異質(zhì)結(jié)結(jié)構(gòu)有效地抑制了光生電子與空穴的復(fù)合，增強(qiáng)了界面電荷傳輸效率，使光催化效率得到了提高。光催化劑循環(huán)使用４次后，U(Ⅵ)的去除率仍在80%左右，說明其穩(wěn)定性比較好。
關(guān)鍵字: 氧化銅；鐵酸鉍；異質(zhì)結(jié)；光催化；還原；鈾
（1. State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, China;
2. China Institute for Radiation Protection, Taiyuan 030006, China）
Abstract:CuO/BiFeO3 heterojunction catalysts were prepared by wetness impregnation method and the structures, morphologies and optical properties of the samples were characterized by SEM, XRD, XPS and UV-Vis. The photocatalytic reduction of U(Ⅵ) in aqueous solution by CuO/BiFeO3 heterojunction catalyst was investigated under visible light irradiation at room temperature and analyzed the mechanism of photocatalytic reduction of U(Ⅵ). The results show that the CuO particles are spherical and smooth in surface, they are monoclinic. BiFeO3 particles are irregular and agglomerated into layers, which are perovskite structure. CuO/BiFeO3 containing 10% CuO exhibited the lowest photoluminescence intensity and the maximum photocatalytic reduction of U(Ⅵ) than pure CuO and BiFeO3 and the removal rate of U(Ⅵ) reached above 96% after 100 min under visible-light irradiation. The improvement of photocatalytic activity of the catalyst is mainly due to the p-n heterostructure formed on the interface of CuO and BiFeO3, which effectively inhibits the recombination of photogene rated electronics and holes, enhances the transfer efficiency of interfacial charge, and improves the photocatalytic efficiency. The removal rate of U(Ⅵ) is above 80% after four cycles, which indicates that CuO/BiFeO3 composite catalyst has an excellent photocatalytic stability.
Key words: copper oxide; bismuth ferrite; heterojunction; photocatalytic; reduction; uranium
