Photocatalyst is a key factor to affect the photoreduction performance. However, the cost of preparing catalysts is relatively high and can be reduced by using waste-based materials. In this study, waste printed circuit boards (PCBs) were used as copper sources to prepare waste-based Cu₂O photocatalyst for photocatalytic reduction of Cr(VI) by chemical precipitation method. Under visible light, the influence factors of photocatalytic reduction activity, such as light intensity, pH, and catalyst dosage, were investigated. Then, the effects of photocatalytic reduction of Cr(VI) by pure Cu₂O, purified Cu₂O and waste-based Cu₂O photocatalysts were compared. The result indicated that the photocatalytic reduction of pure Cu₂O and purified Cu₂O were similar, higher than that of waste-based Cu₂O. X-ray diffraction (XRD) analysis indicates that no new phases were formed in the three catalysts, but their morphologies observed by scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS) was found that the pure Cu₂O and purified Cu₂O are cubic, whereas the waste-based Cu₂O is spherical and contains impurity Sn. It is considered that morphologies and impurity of the catalysts are the key factors for photocatalytic reduction efficiency. Finally, the electron transfer rate and the photocurrent response performance verified that the photocatalytic effect of pure Cu₂O and purified Cu₂O were better than that of waste-based Cu₂O. It is believed that the copper from waste PCBs can be used as high value-added copper material catalysts by an effective preparation process.

中文翻译：

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利用废印刷电路板中的废基 Cu2O 光催化剂对 Cr(VI) 进行可见光驱动光还原

光催化剂是影响光还原性能的关键因素。但是，催化剂的制备成本相对较高，可以通过使用废物基材料来降低成本。在本研究中，以废印刷电路板 (PCB) 为铜源制备废基 Cu ₂ O 光催化剂，用于通过化学沉淀法光催化还原 Cr(VI)。研究了可见光下光催化还原活性的影响因素，如光照强度、pH值和催化剂用量。然后，比较了纯Cu ₂ O、纯Cu ₂ O和基于废物的Cu ₂ O光催化剂光催化还原Cr(VI)的效果。结果表明光催化还原纯Cu ₂O 和纯化的 Cu ₂ O 相似，高于废基 Cu ₂ O。 X 射线衍射（XRD）分析表明三种催化剂中没有形成新相，但通过扫描电子显微镜观察它们的形貌。色散 X 射线光谱 (SEM-EDS) 发现纯 Cu ₂ O 和纯化 Cu ₂ O 是立方体，而基于废物的 Cu ₂ O 是球形并含有杂质 Sn。认为催化剂的形貌和杂质是影响光催化还原效率的关键因素。最后，电子转移率和光电流响应性能验证了纯Cu ₂ O和纯Cu的光催化效果₂ O优于废基Cu ₂ O。相信通过有效的制备工艺，废PCB中的铜可以作为高附加值的铜材料催化剂。