TY - JOUR
T1 - Electrodepositing Polyvinyl Ferrocene Films to Enhance Oxyanion Recovery and Electrode Longevity
AU - Li, Yurui
AU - Román Santiago, Anaira
AU - Kim, Kwiyong
AU - Park, Junhyung
AU - Hladik, Joseph R.
AU - Su, Xiao
AU - Cusick, Roland D.
N1 - This work was funded by the National Alliance for Water Innovation (NAWI) project \u201CNAWI Task 6.16 Redox-Mediated Electrodes for Precision Separation of Nitrogen and Phosphorous Oxyanions\u201D.
PY - 2025
Y1 - 2025
N2 - Rhenium, a critical high-value mineral, naturally occurs as perrhenate (ReO4-) and is difficult to separate from competing anions. Polyvinyl ferrocene (PVF) coated electrodes have exhibited selective adsorption of transition metal oxyanions, but performance degradation with cycling is poorly understood. This study examines the impact of two PVF film fabrication strategies (electrodeposition (ED) and dip-coating (DC)) on (i) rhenium uptake capacity and selectivity, (ii) electrode regeneration and performance longevity, and (iii) lifecycle cost of Re recovery. Electrodeposited PVF films exhibited nearly twice the rhenium uptake (351 ± 82.1 mg Re/g coating) of dip-coating PVF films (158 ± 32.7 mg Re/g coating). Additionally, after 15,000 charge/discharge cycles, Re uptake remained 69.1 ± 11.3% for ED but only 28.0 ± 12.3% for DC films, indicating improved PVF attachment to carbon scaffolds. Operational conditions significantly affected rhenium release after adsorption, with regeneration of 82.6 ± 9.4% at −0.8 V vs Ag/AgCl compared to 30.78 ± 6.2% at 0 V vs Ag/AgCl, due to reduction of both Fe and Re which promoted electrode regeneration at −0.8 V vs Ag/AgCl. A preliminary technoeconomic analysis indicates the high selectivity and longevity of PVF-ED electrodes could facilitate Re recovery at ∼5% of the current market price.
AB - Rhenium, a critical high-value mineral, naturally occurs as perrhenate (ReO4-) and is difficult to separate from competing anions. Polyvinyl ferrocene (PVF) coated electrodes have exhibited selective adsorption of transition metal oxyanions, but performance degradation with cycling is poorly understood. This study examines the impact of two PVF film fabrication strategies (electrodeposition (ED) and dip-coating (DC)) on (i) rhenium uptake capacity and selectivity, (ii) electrode regeneration and performance longevity, and (iii) lifecycle cost of Re recovery. Electrodeposited PVF films exhibited nearly twice the rhenium uptake (351 ± 82.1 mg Re/g coating) of dip-coating PVF films (158 ± 32.7 mg Re/g coating). Additionally, after 15,000 charge/discharge cycles, Re uptake remained 69.1 ± 11.3% for ED but only 28.0 ± 12.3% for DC films, indicating improved PVF attachment to carbon scaffolds. Operational conditions significantly affected rhenium release after adsorption, with regeneration of 82.6 ± 9.4% at −0.8 V vs Ag/AgCl compared to 30.78 ± 6.2% at 0 V vs Ag/AgCl, due to reduction of both Fe and Re which promoted electrode regeneration at −0.8 V vs Ag/AgCl. A preliminary technoeconomic analysis indicates the high selectivity and longevity of PVF-ED electrodes could facilitate Re recovery at ∼5% of the current market price.
KW - capacitive deionization
KW - electrochemical separation
KW - ion-selective removal
KW - rhenium recovery
KW - selective ion exchange
UR - http://www.scopus.com/inward/record.url?scp=85219095978&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85219095978&partnerID=8YFLogxK
U2 - 10.1021/acsestengg.4c00787
DO - 10.1021/acsestengg.4c00787
M3 - Article
AN - SCOPUS:85219095978
SN - 2690-0645
JO - ACS ES and T Engineering
JF - ACS ES and T Engineering
ER -