The hydroxide precipitation with CaO or Ca(OH)₂ is frequently applied in the ferrite formation process of electroplating wastewater, but the excess Ca²⁺ ions present often weaken the quality of the resultant mixed-ferrite (M-Fe₃O₄) precipitates. In this work, for resource utilization of the M-Fe₃O₄ and the Ca²⁺ sources introduced from Ca(OH)₂ in the hydroxide precipitate process, the upconversion assisted magnetite near-infrared (NIR) photocatalysts of M-Fe₃O₄/Tm³⁺/Yb³⁺-doped CaF₂/TiO₂ (FCT) are synthesized. The M-Fe₃O₄ phases possess the advantages of magnetic separation, broadband spectrum absorption, and the heterostructure with TiO₂, and absorb the strong upconversion luminescence emitted from Tm³⁺/Yb³⁺-CaF₂ for photocatalysis. The TiO₂ phase contributes to the large improvement of upconversion luminescence and photocatalytic activity. Because of the stronger UV-Vis-NIR absorption, upconversion luminescence, and electron-hole pair separation for the FCT sample with Ti: Ca molar ratio of 3: 1 (FCT3), higher yields of ^•OH and O₂^•− radicals are generated, which enable FCT3 to possess much enhanced degradation rate (87.3%) of ciprofloxacin compared with those of other FCT samples under UV-Vis-NIR light irradiation. The fabrication of the upconversion magnetite NIR photocatalysts from electroplating wastewater is a promising strategy for its resource utilization and the environmental remediation.

CaO或Ca（OH）₂的氢氧化物沉淀经常用于电镀废水的铁素体形成过程中，但是存在的过量Ca ²⁺离子通常会削弱所得混合铁素体（M-Fe ₃ O ₄）沉淀的质量。 。在这项工作中，为对资源利用M-的Fe ₃ ö ₄和Cα ²⁺选自Ca（OH）引入源₂在氢氧化物沉淀过程中，上变频辅助磁铁矿近红外（NIR）M-的Fe光催化剂₃ O ₄ / Tm ³⁺ / Yb ³⁺掺杂的CaF ₂ / TiO ₂（FCT）被合成。M-Fe ₃ O ₄相具有磁分离，宽带光谱吸收和TiO ₂异质结构的优点，并吸收了Tm ³⁺ / Yb ³⁺ -CaF ₂发出的强上转换发光用于光催化。TiO ₂相有助于大幅提高上转换发光和光催化活性。由于Ti：Ca摩尔比为3：1（FCT3）的FCT样品具有更强的UV-Vis-NIR吸收，上转换发光和电子-空穴对分离的特性，因此^• OH和O ₂ ^•−的产率更高产生了自由基，与其他FCT样品在UV-Vis-NIR光照射下相比，FCT3具有环丙沙星大大提高的降解率（87.3％）。用电镀废水制备上转换磁铁矿近红外光催化剂是一种资源利用和环境修复的有前途的策略。