PECVD-derived oxygen-doped vertical graphene-skinned carbon cloth toward efficient solar steam and water-evaporation-induced electricity cogeneration

Abstract

Integration of solar steam production and water-evaporation-induced electricity generation has become a promising strategy to optimize the existing water-energy nexus. However, owing to the different requirement of material design for water management, satisfying solar steam and water-evaporation-induced electricity cogeneration at high efficiency with a facile and controllable material construction still faces a great challenge. Herein, oxygen-doped vertical graphene (OVG), which possesses vertical structure with high light absorption and abundant nanoconfined channels, was directly deposited on macroporous carbon cloth (CC) by plasma-enhanced chemical vapor deposition (PECVD) to induce strong electrokinetic effect and ensure rapid water evaporation. The creative OVG/CC with different conformal graphene skinned was controllably constructed in PECVD system with the change of deposition temperature and the aid of in-situ carbon-dioxide plasma post-treatment. Benefited from the favorable structure prepared at 800 ℃ with intense light absorption on surface and strong electrical interaction at solid-water interface, the OVG/CC-based device presented efficient outputs with an evaporation rate of 2.78 kg m⁻² h⁻¹, a voltage of 0.75 V and a current of 2.67 μA in DI water, and with an evaporation rate of 2.69 kg m⁻² h⁻¹, a voltage of 0.52 V and a current of 24.11 μA in real seawater respectively, accompanied with the good cycling stability and long-term durability. Moreover, the device could also purify various water sources and drive electron components for practical applications. This work provides a promising CVD strategy for constructing carbon-based composite materials toward efficient clean water and electricity cogeneration.