Abstract In this paper, tetragonal zirconia nanoparticles (ZrO2 NPs) were synthesized via rapid microwave mediated solvothermal method in just 10 min reaction time. A combination of X-ray diffraction, Raman, Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM) and XPS analysis confirmed the formation of single phase tetragonal ZrO2 with average crystallite size ∼ 10 nm. The band gap energy of the synthesized ZrO2 was measured to be 3.67 eV. The photocatalytic behaviour of synthesized ZrO2 NPs was examined for the degradation of two anionic dyes (Eosin Yellow and Bromophenol Blue) and the reduction of Cr(VI) under UV light irradiation. ZrO2 adsorbed and degraded both the dyes within 120 min. At 20 mg/L concentration, more than 96 % of Cr(VI) was reduced to Cr(III) within 60 min. Under the operating conditions, both the degradation of dyes and reduction of Cr(VI) followed pseudo first-order kinetics and rate constant values were inversely dependent on the initial dye concentration. The probable mechanism for the degradation has been proposed through advanced oxidation process. ZrO2 NPs was also found efficient for simultaneous remediation of dye and Cr(VI). The photoreduction of Cr(VI) to Cr(III) was further confirmed from XPS analysis of ZrO2 NPs after chromium reduction.

中文翻译：

---

微波-溶剂热法快速合成四方氧化锆纳米粒子及其对有机染料和六价铬的单组分和双组分体系的光催化活性

摘要 在本文中，通过快速微波介导的溶剂热法在短短 10 分钟的反应时间内合成了四方氧化锆纳米粒子 (ZrO2 NPs)。X 射线衍射、拉曼、扫描电子显微镜 (SEM)、高分辨率透射电子显微镜 (HRTEM) 和 XPS 分析的组合证实了单相四方 ZrO2 的形成，平均晶粒尺寸约为 10 nm。合成的 ZrO2 的带隙能量测量为 3.67 eV。研究了合成的 ZrO2 NPs 在紫外光照射下降解两种阴离子染料（曙红黄和溴酚蓝）和还原 Cr(VI) 的光催化行为。ZrO2 在 120 分钟内吸附并降解了两种染料。在 20 mg/L 的浓度下，超过 96% 的 Cr(VI) 在 60 分钟内被还原为 Cr(III)。在运行条件下，染料的降解和 Cr(VI) 的还原都遵循伪一级动力学，速率常数值与初始染料浓度成反比。已经通过高级氧化过程提出了降解的可能机制。还发现 ZrO2 NPs 可有效同时修复染料和 Cr(VI)。铬还原后 ZrO2 NPs 的 XPS 分析进一步证实了 Cr(VI) 到 Cr(III) 的光还原。