Rice paper-derived adsorbent for gold recovery

Growing global interest in gold (Au) has driven the development of adsorption technologies for sustainable Au recovery from industrial waste. However, conventional adsorbents often rely on complex fabrication and/or petroleum-based chemicals, imposing economic and environmental burdens. Herein, rice paper (RP), a biomass-derived starch material, is transformed into a high-performance Au adsorbent via facile aqueous-phase hydrazination. The resulting hydrazine-functionalized RP (H-RP) exhibits a stratified mesoporous structure, high mechanical integrity, and rapid, effective, and selective Au recovery from complex feed solutions. After adsorption, H-RP can be readily collected and calcined to yield high-purity Au. System-level analyses further demonstrate the economic and environmental benefits of the H-RP-based process for recovering Au from discarded electronics. This study offers a sustainable route to a circular resource economy by integrating Au recovery with biomass valorization.