Ye Weidong, Shao Yingying, Hu Xuefeng, Liu Chulin, Sun Chunyan
Department of Chemistry, Shaoxing University, Shaoxing 312000, Zhejiang, China.
Key laboratory of Coastal Zone Envirenmental Process and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, Shandong, China.
Nanomaterials (Basel). 2017 Apr 3;7(4):76. doi: 10.3390/nano7040076.
A series of high activity photocatalysts g-C3N4-TiO2 were synthesized by simple one-pot thermal transformation method and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller (BET) surface area, and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis-DRS). The g-C3N4-TiO2 samples show highly improved photoreductive capability for the degradation of polybromodiphenyl ethers compared with g-C3N4 under visible light irradiation. Among all the hybrids, 0.02-C3N4-TiO2 with 2 wt % g-C3N4 loaded shows the highest reaction rate, which is 15 times as high as that in bare g-C3N4. The well-matched band gaps in heterojunction g-C3N4-TiO2 not only strengthen the absorption intensity, but also show more effective charge carrier separation, which results in the highly enhanced photoreductive performance under visible light irradiation. The trapping experiments show that holetrapping agents largely affect the reaction rate. The rate of electron accumulation in the conductive band is the rate-determining step in the degradation reaction. A possible photoreductive mechanism has been proposed.
通过简单的一锅热转化法合成了一系列高活性光催化剂g-C3N4-TiO2，并通过透射电子显微镜（TEM）、扫描电子显微镜（SEM）、X射线衍射（XRD）、X射线光电子能谱、布鲁诺尔-埃米特-泰勒（BET）表面积和紫外可见漫反射光谱（UV-Vis-DRS）对其进行了表征。与g-C3N4相比，g-C3N4-TiO2样品在可见光照射下对多溴二苯醚的降解表现出高度提高的光还原能力。在所有杂化物中，负载2 wt% g-C3N4的0.02-C3N4-TiO2表现出最高的反应速率，是纯g-C3N4的15倍。异质结g-C3N4-TiO2中匹配良好的带隙不仅增强了吸收强度，而且显示出更有效的电荷载流子分离，这导致在可见光照射下光还原性能高度增强。捕获实验表明，空穴捕获剂对反应速率有很大影响。导带中电子积累的速率是降解反应中的速率决定步骤。提出了一种可能的光还原机理。
