Influences of Divalent Ions in Natural Seawater/River Water on Nanofluidic Osmotic Energy Generation.
Langmuir
; 38(42): 12935-12943, 2022 10 25.
Article
em En
| MEDLINE
| ID: mdl-36244025
ABSTRACT
Besides the dominant NaCl, natural seawater/river water contains trace multivalent ions, which can provide effective screening of surface charges. Here, in both negatively and positively charged nanopores, influences from divalent ions as counterions and co-ions have been investigated with respect to the performance of osmotic energy conversion (OEC) under natural salt gradients. As counterions, trace Ca2+ ions can suppress the electric power and conversion efficiency significantly. The reduced OEC performance is due to the bivalence and low diffusion coefficient of Ca2+ ions instead of the uphill transport of divalent ions discovered in the previous work. Effectively screened charged surfaces by Ca2+ ions induce an enhanced diffusion of Cl- ions which simultaneously decreases the net ion penetration and ionic selectivity of the nanopore. As co-ions, Ca2+ ions have weak effects on the OEC performance. The promotion from charged exterior surfaces in OEC processes for ultrashort nanopores is also studied, with an effective region of â¼200 nm in width beyond pore boundaries independent of the presence of Ca2+ ions. Our results shed light on the physical details of the nanofluidic OEC process under natural seawater/river water conditions, which can provide a useful guide for high-performance osmotic energy harvesting.
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01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cloreto de Sódio
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Rios
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article