Department of Study in Chemistry, University of Mysore, Manasagagothiri, Mysuru, 570006, India.
Center for Materials Science and Technology, University of Mysore, Vijnana Bhavan, Manasagangothiri, Mysuru, 570006, India.
Chemosphere. 2021 Jun;272:129807. doi: 10.1016/j.chemosphere.2021.129807. Epub 2021 Feb 4.
Design of direct Z-scheme heterojunction photocatalyst is considered as an effective strategy to fully use the high redox potential photogenerated charge carriers. This work reports a novel method for investigating the photosynergistic performance of the Z-scheme MoO/BiO/g-CN (MBG) photocatalyst with peroxymonosulfate (PMS) for the solar degradation of tetracycline hydrochloride (TCH), a model of organic pollutants in wastewater. The results showed a better strategy to activate PMS via accelerating the redox cycle (Mo/Mo), which ultimately induces the successive generation of highly reactive oxygen species. The effect of dosage of the catalyst, PMS, pH of the solution, initial concentrations of TCH and the presence of inorganic anions were investigated. It was found that the degradation of the TCH under sunlight irradiation (SL) was strongly enhanced by the presence of the PMS as an electron acceptor. The MBG/PMS/SL system was able to degrade an initial concentration (40 mg/L) of the TCH solution within 140 min. The good reusability and stability of the MBG catalyst were evaluated by recycling the degradation experiment. The main free radicals are OH and SO which played an important role in the degradation reaction were identified by scavenger experiments and confirmed by EPR spectroscopy. X-ray photoelectron spectroscopy (XPS) study revealed the role of molybdenum ion in the activation process of PMS. The possible synergistic degradation reaction mechanism was proposed.
设计直接 Z 型异质结光催化剂被认为是充分利用高氧化还原电位光生载流子的有效策略。本工作报道了一种新的方法，用于研究 Z 型 MoO/BiO/g-CN（MBG）光催化剂与过一硫酸盐（PMS）在太阳光下降解盐酸四环素（TCH）的协同性能，TCH 是废水中有机污染物的模型。结果表明，通过加速氧化还原循环（Mo/Mo）来更好地激活 PMS，这最终会引发高活性氧物质的连续生成。考察了催化剂、PMS、溶液 pH 值、TCH 初始浓度和无机阴离子存在的用量的影响。结果表明，在太阳光照射（SL）下，PMS 作为电子受体的存在强烈增强了 TCH 的降解。MBG/PMS/SL 体系能够在 140 分钟内降解初始浓度（40mg/L）的 TCH 溶液。通过重复降解实验评估了 MBG 催化剂的良好可重复使用性和稳定性。通过清除实验和 EPR 光谱证实，确定了在降解反应中起重要作用的主要自由基是 OH 和 SO。X 射线光电子能谱（XPS）研究揭示了钼离子在 PMS 活化过程中的作用。提出了可能的协同降解反应机制。
