Huiyue Wang, Mengjie Xu, Xueying Wen, Guixin Hu, Qianyu Wei, Lingling Feng, Xinyao Zhang, Ran Niu, Jiang Gong*

Efficient solar-driven interfacial steam-hydropower co-generation by high-quality carbon nanotube from discarded polyolefin separator

Energy Materials (2026) in press, (IF2026 = 11.9)

Converting discarded polyolefin separators into valuable carbon nanotube (CNT) not only contributes to high-value utilization of discarded separators, but also offers a green approach to construct advanced CNT-based generators. However, the controlled carbonization of discarded polyolefin separators into high-quality CNT remains challenging, and the electricity generation mechanism of CNT remains obscure. Herein, we report the “all-in-one” catalytic strategy using multi-component Ni/Mo/Mg catalysts to realize the controllable carbonization of discarded polyolefin separators into high-quality CNT. By adding Mo and Mg into Ni in a mole ratio of 5/0.1/0.5 (Ni/Mo/Mg), the catalyst displays high catalytic activity, dispersion, and stability, and achieves a CNT yield of 57.4 wt%. Thanks to the good photothermal conversion capability and dramatic wettability, the CNT evaporator realizes an evaporation rate of 2.73 kg m^-2 h^-1, photo-to-thermal efficiency of 95.4%, together with an open voltage of 0.221 V under laboratory conditions, which ranks as one of the most efficient evaporators/generators. In practical experiments, the total water production and voltage output are 2.51 kg m^-2 over 5 h and 0.215-0.265 V, respectively. Molecular dynamics (MD) simulation results show that the surface functional groups have stronger interactions with H⁺ than OH^-. With the continuous evaporation of bulk water, H⁺ moves faster upward along the nanochannel than OH^-, thus forming a potential difference. This study provides an eco?friendly route for synthesizing advanced carbon nanomaterials and co-generating freshwater and electricity.

Keywords: Interfacial solar steam generation, freshwater-electricity co-generation, carbon nanotube, solar-to-thermal conversion, discarded polyolefin separators