Abstract:

The addition of surfactant in the preparation process can affect the morphology and size of photocatalyst nanoparticles, thereby affecting their photocatalytic efficiency. In this work, the Ca-doped β-In₂S₃ photocatalysts with different surfactants were prepared by a hydrothermal method. The physicochemical properties of the prepared photocatalysts were characterized by XRD, SEM, XPS and UV-vis DRS. The results showed that the addition of SDS and CTAB had no obvious effect on the morphology and structure of Ca-doped β‍-In₂S₃ photocatalyst, but the introduction of CHSB and PVP significantly changed its morphology and structure. In particular, the addition of PVP greatly promoted the growth of lamellar structure of Ca-doped β-In₂S₃, showing the richest lamellar structure and the largest specific surface area, which could increase the active sites on the surface of the photocatalyst and improve its photocatalytic performance. The degradation rate of MO could reach 98.38% in 30min. With the increase of PVP content from 0 to 0.022g, the photocatalytic degradation rate was gradually improved, and then continued to increase to 0.033g, the promotion effect was not obvious. Free radical trapping experiments proved that photo-generated holes and superoxide radicals were the main active materials in the photocatalytic process. The degradation mechanism of MO was analyzed by the above characterization methods combined with free radical trapping experiments. This paper could provide a reference for the addition of surfactants in the preparation of semiconductor photocatalysts by hydrothermal method.

Key words: surfactant, Ca-doped, indium sulfide (In₂S₃), photocatalysis, methyl orange

摘要：

制备过程中添加表面活性剂可以影响光催化剂纳米颗粒形貌与尺寸等，从而影响其光催化性能。本工作采用水热法制备了添加不同表面活性剂的Ca掺杂β-In₂S₃光催化剂，通过X射线衍射、扫描电子显微镜、X射线光电子能谱、紫外可见漫反射光谱等对制备的光催化剂进行了理化性能表征。结果表明：SDS与CTAB的加入，对Ca掺杂β-In₂S₃光催化剂的形貌结构影响不明显，而CHSB与PVP的加入，明显改变了其形貌结构。尤其是PVP的加入极大促进了Ca掺杂β-In₂S₃片状结构的生长，展现出最丰富的片状结构和最大的比表面积，这将增加光催化剂表面的活性位点，提升其光催化性能，30min可实现98.38%的甲基橙（MO）降解率。随着PVP含量从0增加到0.022g，光催化效果逐渐提升，再继续增加到0.033g时，提升效应不明显。自由基捕获实验证明光催化过程中光生空穴和超氧自由基是主要的活性物质。并通过以上表征手段结合自由基捕获实验分析了该光催化剂对MO的降解机理。本文可为水热法制备半导体光催化剂过程中表面活性剂的添加提供参考。

关键词: 表面活性剂, 钙掺杂, 硫化铟, 光催化, 甲基橙