Thiol functionalized mesoporous silicas for selective adsorption of precious metals

Thiol functionalized mesoporous silica (TFMS) with ordered hexagonal pore structure was fabricated by one-step synthesis pathway. The selective adsorption for precious metals was investigated using single component and binary adsorption solutions. The TFMS displayed strong affinity for gold or platinum in specific conditions with a large adsorption capacity, and showed a high selectivity in the binary solutions within 30 min. Furthermore, gold and platinum could be totally recovered by elution with 5 M HCl and 0.7 M thiourea–2 M HCl, respectively.