水热法合成NCQD/BiOCl复合物及其光催化分解水性能

Hydrothermal Synthesis of NCQD/BiOCl Composites and Their Efficient Photocatalytic Performances for Hydrogen Production from Water

以葡萄糖和甘氨酸为原料,首先经水热途径制备了含氮碳量子点(NCQD)。接着以硝酸铋为反应物,聚乙烯吡咯烷酮K30(PVP-K30)为模板剂,NCQD为载体,通过水热法合成得到NCQD/BiOCl复合物。运用透射电镜(TEM)、场发射扫描电镜(FESEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、紫外-可见吸收光谱(Uv-Vis)和荧光发射光谱对NCQD/BiOCl复合物进行了形貌、结构和物性表征。TEM分析揭示2～3nm的NCQD均匀分散在BiOCl纳米片表面。在模拟太阳光的条件下,研究了NCQD/BiOCl复合物的光电流和光催化制氢性能。结果显示,NCQD/BiOCl复合物的带隙为2.8eV,光响应电流约为纯BiOCl的3.6倍。NCQD的质量分数为5%的NCQD/BiOCl复合物显示了最佳的产氢性能,室温下光照5h后的产氢速率为19.34μmol·h^(-1),显著高于相同条件下纯BiOCl的产氢速率(1.06μmol·h^(-1))。此外,该复合物具有优异的循环产氢性能,5次光催化后产氢比容量还能保留起始值的98%。

Using glucose and glycine as raw materials,nitrogen-doped carbon dots（NCQD）was prepared firstly via a hydrothermal approach.Then the NCQD/BiOCl composite was synthesized by a hydrothermal method,utilizing bismuth nitrate as the reactant,polyvinylpyrrolidone-K30（PVP-K30）as the template and NCQD as the support,respectively.The morphology,nanostructure and physicochemical properties of the NCQD/BiOCl composite were characterized by transmission electron microscopy（TEM）,field emission scanning electron microscopy（FESEM）,X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）,ultraviolet visible absorption spectroscopy（Uv-Vis）and fluorescence emission spectrum.The TEM characterization reveals that the NCQD with the size of 2～3 nm is well-distributed on the surface of BiOCl nanosheets.Furthermore,the photocurrent response and photocatalytic hydrogen production performances were studied under the irradiation of simulated sunlight.The experimental results show that the band gap of the NCQD/BiOCl composite is 2.8 eV and its photocurrent response is about 3.6 times higher than that of pristine BiOCl.The NCQD/BiOCl composite with a relative NCQD content of 5% shows a highest photocatalytic hydrogen production rate,which reaches 19.34μmol·h^（-1） after a 5 hirradiation at room temperature,also remarkably higher than that of the pristine BiOCl（1.06μmol·h^（-1））.In addition,the NCQD/BiOCl composite exhibits an excellent cyclic stability of hydrogen production.The specific photocatalytic capacity retains 98% of the initial value after 5 cycles.