Water, the primary source of life, is contaminated with various organic/inorganic impurities in the course of development. Organic dyes, a waste product from dying industries, have evolved as one of the major contributor to water pollution. The present work involves the photocatalytic degradation of malachite green dye as a model substrate using zinc oxide nanoparticles (ZnO NPs) and its composite with β-cyclodextrin (β-CD). ZnO NPs are found to be a worthy catalyst due to their bandgap and easy availability. The role of β-CD in ZnO photocatalyst is explored. With ZnO NPs, electron–hole recombination takes place very easily; hence, to restrict this recombination β-CD has been used. We have characterized the synthesized nanomaterials by using powder X-ray diffraction, Fourier transform infrared, thermogravimetric analysis, diffuse reflectance spectroscopy (DSR), scanning electron microscopy and transmission electron microscopy (TEM). Various parameters, such as the concentration of dye, pH and amount of catalyst have optimized for the photocatalysis process. More basic medium adsorption is more favourable than degradation, which decreases the reusability of the catalyst. Based on the photodegradation efficiency and rate constant (k), we observed that ZnO–β-CD showed better photocatalytic activity than ZnO NPs. The plausible mechanism for photocatalytic degradation has also been reported with the help of photoluminescence spectra and scavenger activity.

水是生命的主要来源，在发展过程中被各种有机/无机杂质污染。有机染料是染色工业的一种废品，已发展成为造成水污染的主要因素之一。目前的工作涉及使用氧化锌纳米颗粒（ZnO NPs）及其与β-环糊精（β-CD）的复合物光催化降解孔雀石绿染料作为模型基材。由于其带隙和容易获得，ZnO NPs 被发现是一种有价值的催化剂。探讨了 β-CD 在 ZnO 光催化剂中的作用。使用 ZnO NPs，电子-空穴复合很容易发生；因此，为了限制这种重组，使用了 β-CD。我们通过使用粉末 X 射线衍射、傅里叶变换红外、热重分析、漫反射光谱 (DSR)、扫描电子显微镜和透射电子显微镜 (TEM)。各种参数，例如染料的浓度、pH 值和催化剂的量，都针对光催化过程进行了优化。更多的碱性介质吸附比降解更有利，这降低了催化剂的可重复使用性。基于光降解效率和速率常数 (k)，我们观察到 ZnO-β-CD 比 ZnO NPs 表现出更好的光催化活性。在光致发光光谱和清除剂活性的帮助下，也报道了光催化降解的合理机制。更多的碱性介质吸附比降解更有利，这降低了催化剂的可重复使用性。基于光降解效率和速率常数 (k)，我们观察到 ZnO-β-CD 比 ZnO NPs 表现出更好的光催化活性。在光致发光光谱和清除剂活性的帮助下，也报道了光催化降解的合理机制。更多的碱性介质吸附比降解更有利，这降低了催化剂的可重复使用性。基于光降解效率和速率常数 (k)，我们观察到 ZnO-β-CD 比 ZnO NPs 表现出更好的光催化活性。在光致发光光谱和清除剂活性的帮助下，也报道了光催化降解的合理机制。