CuS nanotube/g-C3N4异质结的合成及光催化性能

以CuCl₂·2H₂O、SC（NH₂）₂和g-C₃N₄纳米片作为前驱体，在室温下采用简单的共沉淀法成功地制备了CuS nanotube/g-C₃N₄异质结。对碱源、g-C₃N₄加入顺序和反应时间等合成条件对CuS nanotube/g-C₃N₄异质结的光催化性能的影响进行了较系统的研究。结果表明:碱源是合成的关键因素。以Na₂S·9H₂O为碱源兼硫源，制备的CuS nanotube/g-C₃N₄异质结的光吸收边带明显红移，禁带宽度（E_g）和荧光强度明显降低，且光电流响应值为0.095 6 μA/cm²，相对于bulk g-C₃N₄提高了约3.1倍。将其用于光催化降解罗丹明B（RhB），45 min内RhB降解率约达100%，其降解速率相对于bulk g-C₃N₄提高了约47.6倍，这些结果说明CuS nanotube/g-C₃N₄具有较高的光电催化活性。并提出了CuS nanotube/g-C₃N₄异质结在光催化过程中载流子迁移转化的机理。

Synthesis and Photocatalytic Performances of CuS Nanotube/g-C3N4 Heterojunction

The CuS nanotube/g-C₃N₄ heterojunction was successfully prepared by simple co-precipitation method at room temperature with CuCl₂·2H₂O，SC（NH₂）₂ and g-C₃N₄ nanosheets as precursors. The effects of synthesis conditions such as alkali source，addition sequence of g-C₃N₄ and reaction time on the photocatalytic performances of the CuS nanotube/g-C₃N₄ heterojunction was systematically investigated. The results showed that the alkali source is the key factor during the synthesis. With Na₂S·9H₂O as the alkali and sulfur source，the light absorption sideband of the CuS nanotube/g-C₃N₄ heterojunction is significantly red-shifted，band gap（E_g） and fluorescence intensity are significantly reduced， while the photocurrent-response value is 0.095 6 μA/cm²，which is about 3.1 times higher than that of bulkg-C₃N₄. It was used for photocatalytic degradation of rhodamine B（RhB），and the degradation rate of RhB reaches about 100% within 45 min，which is about 47.6 times higher than that of bulk g-C₃N₄，indicating that the CuS nanotube/g-C₃N₄ heterojunction has higher photoelectrocatalysis activity. The mechanism of carrier migration and transformation of CuS nanotube/g-C₃N₄ heterojunction in the photocatalytic process was proposed.