A wave-powered capacitive deionization system with in-situ blue energy harvester

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-10, Vol.498, p.155530, Article 155530
• Main Authors: Ren, Jinlong, Fang, Liyang, Qu, Hang, Zhou, Tao, Chen, Chunjin, Wei, Qi, Kang Shen, Pei, Wan, Lingyu, Qun Tian, Zhi
• Format: Article
• Language: English
• Subjects: Capacitive deionization; Coaxial hybrid nanogenerators; Desalination; Wave energy harvesting; Wave-powered capacitive deionization system
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.155530

[Display omitted] •A wave-powered capacitive deionization system (WPCDIS) was developed.•WPCDIS consists of a hybrid nanogenerator and a capacitive deionization cell.•This WPCDIS operates well under real ocean wave conditions.•The system provides a new route for obtaining freshwater in offshore areas. Developing desalination technology driven by in-situ ocean wave energy presents great promise to obtain low-cost freshwater from seawater. Herein, a newly designed wave-powered capacitive deionization system (WPCDIS) was developed for the first time. The system comprises a coaxial hybrid nanogenerator (CH-NG) and a low-energy consuming capacitive deionization (CDI) cell, in which CH-NG is assembled by a triboelectric nanogenerator (TENG), an electromagnetic generator (EMG) and a piezoelectric nanogenerator (PENG) into a coaxial rotating structure to efficiently harvest energy from water wave with a low frequency of down to 0.2 Hz, and the CDI cell with a salt adsorption capacity (SAC) of 28.0 mg g−1 at 1.5 V using NaCl solution with a concentration of 500 mg L-1 is fabricated by 3D porous graphene (3DPG) and activated carbon (AC) as the salt ion adsorption electrode. Unlike conventional desalination methods requiring an external power source, the WPCDIS can be run by harvesting wave energy in real time, and exhibits continuous and stable desalination performance. In addition, the test on the ocean also demonstrates the feasibility of the system for practical application. The design developed in the work provides a novel self-powered desalination technology based on the wave energy harvesting strategy, offering a new way of obtaining freshwater in real time on the ocean.