Liao Yongliang, Zhu Shenmin, Chen Zhixin, Lou Xianghong, Zhang Di
State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
Phys Chem Chem Phys. 2015 Nov 7;17(41):27826-32. doi: 10.1039/c5cp05186j.
Activated graphitic carbon nitride (g-C3N4) with enhanced photocatalytic capability under visible light irradiation was fabricated by using a facile chemical activation treatment method. In the chemical activation, a mixed solution of hydrogen peroxide and ammonia was employed. The yield can reach as high as 90% after the activation process. The activation process did not change the crystal structure, functional group, morphology and specific surface area of pristine g-C3N4, but it introduced H and O elements into the CN framework of g-C3N4, resulting in a broader optical absorption range, higher light absorption capability and more efficient separation of photogenerated electrons and holes. The photoactivity was investigated by the degradation of rhodamine B (RhB) under visible light irradiation. As compared to the pristine g-C3N4, the activated g-C3N4 exhibited a distinct and efficient two-step degradation process. It was found that the RhB dye in the activated g-C3N4 was mainly oxidized by the photogenerated holes. It is believed that sufficient holes account for the two-step degradation process because they would significantly improve the efficiency of the N-de-ethylation reaction of RhB.
采用简便的化学活化处理方法制备了在可见光照射下具有增强光催化能力的活化石墨相氮化碳（g-C3N4）。在化学活化过程中，使用了过氧化氢和氨的混合溶液。活化过程后产率可高达90%。活化过程没有改变原始g-C3N4的晶体结构、官能团、形态和比表面积，但将H和O元素引入到g-C3N4的CN骨架中，导致光吸收范围变宽、光吸收能力增强以及光生电子和空穴的分离更高效。通过在可见光照射下罗丹明B（RhB）的降解来研究光活性。与原始g-C3N4相比，活化后的g-C3N4表现出明显且高效的两步降解过程。发现活化g-C3N4中的RhB染料主要被光生空穴氧化。据信，充足的空穴是两步降解过程的原因，因为它们会显著提高RhB的N-脱乙基反应效率。
