Modification assisted Cu2O/MCM-41 nanoarchitecture toward efficient recovery of Au (III)

A Cu2O and thiourea functionalized MCM-41 (CMTU) nanoarchitecture was prepared for selective recovering of Au (III) from an acidic solution. The material was probed by using SEM-EDS, XPS, XRD, FTIR, and zeta potential to explicate the mechanisms involved in Au (III) recovery. Results revealed that Au (III) (as [AuCl4](-), pH = 3.0) initially was bound with -NH2 and C=S on the CMTU surface through electrostatic attraction and chelation, respectively. Then, Au (III) was readily reduced to Au (I) and Au (0) by Cu (I). The maximum adsorption capacity of Au (III) reached 3180.45 mg.g(-1) at the initial pH = 3.0 at 318 K, and the adsorption process followed the Langmuir model and pseudo-second-order model. The calculated thermodynamic parameters expounded that Au (III) recovery by CMTU was a spontaneously endothermic process. Furthermore, CMTU showed excellent selectivity and reusability.

Automated summary

A Cu2O and thiourea functionalized MCM-41 (CMTU) nanoarchitecture was prepared for selectively recovering Au (III) from an acidic solution. The material achieved this through electrostatic attraction and chelation, resulting in the binding of Au (III) to the CMTU surface. Cu (I) then readily reduced Au (III) to Au (I) and Au (0). This material displayed excellent adsorption capacity, followed specific models for adsorption, and exhibited a spontaneously endothermic recovery process, as well as high selectivity and reusability.