The efficient recovery of silver from wastewater is of great significance due to its economic value and environmental concern. In this work, DL-cysteine and NO 3 − intercalated MgAl-layered double hydroxide (MgAl-LDH) is fabricated through the coprecipitation method, and the resultants (MgAl-NO3 and MgAl-DL) are applied for Ag+ recovery under light irradiation. Compared with the pristine MgAl-NO3, MgAl-DL exhibits a maximum Ag+ uptake of 1702.5 mg g−1, far exceeding that of MgAl-NO3 (104.6 mg g−1) and most previously reported adsorbents. Furthermore, in a simulated silver-containing electroplating wastewater system using a filtration column, MgAl-DL continuously extracted Ag+ over 129 h with a maintained extraction efficiency above 95%. The excellent performance of MgAl-DL can be attributed to two main factors: (i) the intercalated DL provides abundant adsorption sites for Ag+ and (ii) the modified electronic structure of MgAl-DL facilitates a charge transfer pathway from the LDH laminates to the interlayer DL and subsequently to Ag+, effectively promoting the separation and migration of photogenerated charge carriers. This work offers a practical and energy-efficient strategy for sustainable recovery of precious metals from wastewater.
