Currently, environmental pollution due to contaminants released from industries into clean water is a big challenge to maintain public health worldwide. The elimination of organic toxins, particularly organic dyes using semiconductor-mediated photocatalysis is an efficient technique. Herein, Zn_0.9Ho_0.05M_0.05O (M = Pr, Sm, Er) photocatalysts were prepared by the co-precipitation method and characterized via state-of-art techniques to study the structural, optical, electrochemical, and morphological properties. XRD results confirmed that the grown ZnO-based catalysts have hexagonal wurtzite structures with high crystallinity and successful co-doping. FTIR and Raman analysis have shown the vibrational bands and optical phonon modes of ZnO in all catalysts with a small shift which further evident the co-doping. Roughly spherical morphology revealed by FE-SEM images with improvement by co-doping. The energy bandgap of grown ZnO depends on dopants and is decreased by co-doping compared to single-doped samples, as evident from UV-Visible analysis. The photocatalytic degradation experiment towards methyl orange (MO) and methylene blue (MB) dyes under sunlight exhibited that co-doped catalysts have higher efficiency against both dyes. Remarkably, Ho-Er co-doped catalyst degraded 99.7% MB and 84% MO dye under 60 min sunlight illumination with a higher apparent rate constant of 0.0975 and 0.028 min⁻¹, respectively, with stability up to 6th cycle against MB dye. The scavenger tests demonstrate that the major role in the enhanced photodegradation is superoxide ($O_2^{*-}$) and hydroxyl (OH*) radicals. The boosted photocatalytic activity is due to the lower energy bandgap, and the higher flow of charge carrier (EIS results) led to the higher generation of reactive species. Moreover, these consequences revealed that the individual performance of ZnO could be boosted through rare earth elements co-doping to make it useful for environmental applications.

目前，由工业释放到清洁水中的污染物造成的环境污染是维持全球公共卫生的一大挑战。使用半导体介导的光催化消除有机毒素，特别是有机染料是一种有效的技术。在此，通过共沉淀法制备了 Zn _0.9 Ho _0.05 M _0.05 O (M = Pr, Sm, Er) 光催化剂，并通过最先进的技术对其结构、光学、电化学和形态特性进行了表征。XRD结果证实生长的ZnO基催化剂具有高结晶度的六方纤锌矿结构和成功的共同兴奋剂。FTIR 和拉曼分析显示了所有催化剂中 ZnO 的振动带和光学声子模式，位移很小，这进一步证明了共掺杂。FE-SEM 图像显示的大致球形形态通过共掺杂得到改善。与单掺杂样品相比，生长的 ZnO 的能带隙取决于掺杂剂，并且通过共掺杂降低，这从紫外-可见光分析中可以看出。在阳光下对甲基橙（MO）和亚甲蓝（MB）染料的光催化降解实验表明，共掺杂催化剂对这两种染料都有更高的效率。值得注意的是，Ho-Er 共掺杂催化剂在 60 分钟的阳光照射下降解了 99.7% MB 和 84% MO 染料，具有更高的表观速率常数，分别为 0.0975 和 0.028 min ^-1，分别对 MB 染料具有高达第 6 个循环的稳定性。清除剂测试表明，增强光降解的主要作用是超氧化物（${○}_2^{*-}$) 和羟基 ( OH *) 自由基。提高的光催化活性是由于较低的能带隙，较高的载流子流量（EIS 结果）导致更多的活性物质产生。此外，这些结果表明，可以通过稀土元素共掺杂来提高 ZnO 的单独性能，使其可用于环境应用。