Enhancing the osmotic energy conversion of a nanoporous membrane: influence of pore density, pH, and temperature. Issue 8 (8th February 2023)

• Record Type: Journal Article
• Authors: Zheng, Ding-Cheng; Hsu, Jyh-Ping
• Is Part Of: Physical chemistry chemical physics. Volume 25:Issue 8(2023)
• Page Start: 6089
• Page End: 6101
• Publication Date: 2023-02-08
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d2cp05831f
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Salinity gradient power, which converts Gibbs free energy of mixing to electric energy through an ion-selective pore, has great potential. Abstract : Salinity gradient power, which converts Gibbs free energy of mixing to electric energy through an ion-selective pore, has great potential. Towards practical use, developing membrane-scaled nanoporous materials is desirable and necessary. Unfortunately, the presence of a significant ion concentration polarization (ICP) lowers appreciably the power harvested, especially at a high pore density. To alleviate this problem, we suggest applying an extra pressure difference Δ P across a membrane containing multiple nanopores, taking account of the associated power consumption. The results gathered reveal that the application of a negative pressure difference can improve the power harvested due to the enhanced selectivity. In addition, if the pore density of a membrane is high, raising its pore length is necessary to make the energy harvested economic. For example, if the pore length is 2000 nm and the pore density is 2.5 × 10 9 pores per cm 2, an increment in the power density of 213 mW m −2 can be obtained by applying Δ P = −1 bar at pH 11 and 323 K, where a net positive power density can be retrieved. The performance of the system considered under various conditions is examined in detail, along with associated mechanisms.