A series of Ag2S-Ag2CO3 (4%, 8%, 16%, 32%and 40%Ag2S), Ag2CO3@Ag2S (32%Ag2S) and Ag2S@Ag2CO3 (32%Ag2S) heterojunction photocatalysts were fabricated by coprecipitation or successive precipitation reaction. The obtained catalysts were analyzed by N2physical adsorption, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy(FT-IR), Raman spectroscopy(Raman) and UV-VIS diffuse reflectance spectroscopy (UV-VIS DRS). Under visible light irradiation, the influences of Ag2S content and core-shell property on photocatalytic activity and stability were evaluated in studies focused on the degradation of methyl orange (MO) dye and phenol. Results showed that excellent photocatalytic performance was obtained over Ag2S/Ag2CO3 heterojunction photocatalysts with respect to Ag2S and Ag2CO3. With optimal content of Ag2S (mass fraction of 32 %), the Ag2S-Ag2CO3 showed the highest photocatalytic degradation efficiency. Moreover, the structured property of Ag2S/Ag2CO3 greatly influenced the activity. Compared with Ag2S -Ag2CO3 and Ag2CO3@Ag2S, core-shell like Ag2S@Ag2CO3 demonstrated the highest activity and stability. The main reason for the boosting of photocatalytic performance was due to the formation of Ag2S/Ag2CO3 heterojunction with well contacted interface and unique electron structures. Ag2S/Ag2CO3 heterojunction could significantly increase the separation efficiency of the photo-generated electrons (e-) and holes(h+), and production of oOH radicals. More importantly, the low solubility of Ag2S shell could effectively protect the core of Ag2CO3, which further guarantees the stability of Ag2CO3.%通过共沉淀与连续沉淀法制备了一系列复合催化剂Ag2S-Ag2CO3(4%,8%,16%,32%和40%Ag2S)以及Ag2CO3@Ag2S(32%Ag2S),Ag2S@Ag2CO3(32%Ag2S)异质结光催化剂.利用了N2物理吸附、X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、傅里叶变换红外光谱(FT-IR)、拉曼光谱(Raman)和紫外可见漫反射光谱(UV-vis DRS)、瞬态光电流响应(TPR)对所制备的催化剂进行表征.在可见光的照射下,研究Ag2S复合量和核壳结构对Ag2CO3降解甲基橙、苯酚和双酚A的光催化活性与稳定性.结果表明:Ag2S/Ag2CO3异质结光催化剂相比Ag2S和Ag2CO3具有更高效的光催化性能.当Ag2S的掺杂量(质量分数)为32%时,Ag2S-Ag2CO3的光催化降解效率最高.而且Ag2S/Ag2CO3异质结结构对光催化性能有很大影响.对比Ag2S-Ag2CO3和Ag2CO3@Ag2S,核壳结构的Ag2CO3@Ag2S拥有更好的活性与稳定性.光催化性能增强的主要原因是Ag2S/Ag2CO3异质结的形成而拥有优异的表面性能与独特的电子结构.同时,Ag2S/Ag2CO3异质结结构可以很好地促进光生电子空穴的分离与·OH自由基的产生.更重要的是,表壳Ag2S的低溶解性可以有效地保护核心Ag2CO3,使Ag2CO3更加稳定.
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