Efficient Degradation of Ciprofloxacin via Peroxymonosulfate Activation over a Hierarchically Porous Cu–Ti Alloy Manufactured by 3D Printing

3D printed alloy catalysts have garnered significant attention in water purification due to their high efficiency, adaptable structure, and easy recovery. Here, a straightforward and cost-effective three-dimensional (3D) printing strategy is adopted to synthesize a copper–titanium (Cu–Ti) alloy for ciprofloxacin (CIP) degradation through peroxymonosulfate (PMS) activation. The resulting 3D Cu–Ti alloy, characterized by a hierarchical porous structure, exhibits the highest removal efficiency of 90.55% for CIP degradation, surpassing that of commercial Cu and Ti powders under similar conditions. Capture experiments and electron paramagnetic resonance measurements reveal the involvement of •OH, 1O2, SO4•–, and O2•– in the degradation of CIP, with •OH and 1O2 playing dominant roles. The presence of Ti not only promotes Cu(I)/Cu(0) and Cu(II)/Cu(I) cycling but also facilitates the activation of dissolved oxygen in water, thereby reducing its reaction with PMS and preventing corrosion, ultimately rendering the 3D–Cu-Ti/PMS alloy excellent catalytic activity and reusability. Additionally, bean sprout growth experiments indicate a remarkable reduction in the toxicity of CIP degradation products. The utilization of 3D printing technology for the construction of a Cu–Ti alloy offers a promising strategy for the removal of CIP through PMS activation.