CuS/CQDs/g-C_(3)N_(4)复合材料的合成及光催化性能

Synthesis and Photocatalytic Properties of CuS/CQDs/g-C_(3)N_(4)

本工作以三水合硝酸铜(Cu(NO_(3))_(2)·3H_(2)O)、硫脲(CH_(4)N_(2)S)和柠檬汁为原料,基于水热法获得碳量子点(Carbon quantum dots,CQDs),采用超声震荡法成功合成了CuS/CQDs/g-C_(3)N_(4)三相复合光催化材料,构建了p-n型异质结。通过X射线衍射(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)、光致发光光谱(PL)、氮气吸附-脱附测试(BET)和紫外-可见光漫反射光谱(UV-Vis DRS)等方法对材料的晶体结构、微观形貌和孔结构进行了详细表征。结果表明:三相复合材料界面结构构建良好,纯度高,各相分布均匀。光催化降解实验中,当CuS的含量为10%(质量分数)时,CuS/CQDs/g-C_(3)N_(4)复合材料的光催化降解效果达到最佳(72.1%)。复合材料在经过四次循环降解RhB后,其光催化降解效率仍然保持在65.2%。光催化实验结果表明,·O_(2)^(-)自由基是光催化降解产生的主要因素,h^(+)自由基的作用次之。

CQDs (Carbon quantum dots) were obtained by hydrothermal method with lemon juice as the carbon source. CuS/CQDs/g-C_(3)N_(4) was synthesized using copper trihydrate nitrate (Cu(NO_(3))_(2)·3H_(2)O), thiourea(CH_(4)N_(2)S) and lemon juice as starting materials via ultrasonic shock method. CuS/CQDs/g-C_(3)N_(4) three-phase composite photocatalyst with p-n-type heterojunction structure was obtained successfully. The structure and morphology of the material were analyzed by various methods, such as XRD, SEM, TEM, XPS, PL, BET and UV-Vis. The results showed that the interface structure is well constructed with high purity and uniform distribution. In the photocatalytic degradation experiment, the best photocatalytic degradation of the CuS/CQDs/g-C_(3)N_(4) composite was achieved at approximately 72.1% when the CuS content was 10wt%. After the RhB degradation in 4 cycles, the photocatalytic degradation efficiency of the composite material was not significantly reduced, and it still remained at 65.2%. Finally, it is clear that ·O_(2)^(-)radical is the main factor in photocatalytic degradation, and h^(+) radical is the second factor.