Faculty of Materials Science and Ceramics, AGH University of Science and Technology, 30-059 Kraków, Poland.
Molecules. 2021 Nov 25;26(23):7123. doi: 10.3390/molecules26237123.
Semiconductor photocatalysis is considered one of the most promising technologies for water purification from toxic organic dyes. However, to reliably evaluate the possibility of using a given material as a photocatalyst, it is crucial to investigate not only the photocatalytic activity but also its affinity towards various dyes and reusability. In this work, we studied the adsorptive/photocatalytic properties of hollow-spherical raspberry-like SnO and its SnO/SnS heterostructures that were obtained via a chemical conversion method using three different concentrations of a sulfide precursor (thioacetamide). The adsorptive/photocatalytic properties of the samples towards cationic rhodamine B (RhB) and anionic indigo carmine (IC) were analyzed using uncommon wall zeta potential measurements, hydrodynamic diameter studies, and adsorption/photodecomposition tests. Moreover, after conducting cyclic experiments, we investigated the (micro)structural changes of the reused photocatalysts by scanning electron microscopy and Fourier-transform infrared spectroscopy. The obtained results revealed that the sensitization of SnO resulted not only in the significantly enhanced photocatalytic performance of the heterostructures, but also completely changed their affinity towards dyes. Furthermore, despite the seemingly best photocatalytic performance, the sample with the highest SnS content was unstable due to its (micro)structure. This work demonstrates that dye adsorption/desorption processes may overlap the results of cyclic photodecomposition kinetics.
半导体光催化被认为是从有毒有机染料中净化水的最有前途的技术之一。然而，要可靠地评估给定材料作为光催化剂的可能性，不仅要研究其光催化活性，还要研究其对各种染料的亲和力和可重复使用性。在这项工作中，我们通过化学转化法使用三种不同浓度的硫化物前体（硫代乙酰胺）研究了中空球形覆盆子状 SnO 及其 SnO/SnS 异质结构的吸附/光催化性能。使用不常见的壁面 ζ 电位测量、水动力直径研究和吸附/光分解测试分析了样品对阳离子罗丹明 B（RhB）和阴离子靛蓝胭脂红（IC）的吸附/光催化性能。此外，在进行循环实验后，我们通过扫描电子显微镜和傅里叶变换红外光谱研究了再用光催化剂的（微）结构变化。所得结果表明，SnO 的敏化不仅显著提高了异质结构的光催化性能，而且完全改变了它们对染料的亲和力。此外，尽管具有看似最佳的光催化性能，但具有最高 SnS 含量的样品由于其（微）结构而不稳定。这项工作表明，染料吸附/解吸过程可能会影响循环光分解动力学的结果。
