Huiyue Wang, Xueying Wen, Guixin Hu, Hongrun Zhu, Zhikun Dai, Xinyao Zhang, Qianyu Wei, Huajian Liu*, Ran Niu*, Jiang Gong*

Co-enhancing interfacial solar-driven evaporation and hydrovoltaic electricity generation by porous carbon nanoparticle from waste polyester

Journal of Materials Chemistry A (2025) Accept.

The solar energy collection through the natural process of water evaporation for interfacial evaporation and electricity generation has emerged as a promising method for freshwater and electricity co-generation. However, it remains a challenge to develop a high-performance porous carbon nanomaterial-based multifunctional evaporator. Herein, we propose the green synthesis of porous carbon nanoparticles (PCN) through the pyrolysis of calcium-based metal-organic framework derived from waste polyester and prepare PCN evaporators for freshwater and electricity co-generation. The PCN-based evaporator is characterized by low evaporation enthalpy, excellent photothermal conversion, effective sunlight absorption, abundant functional groups, and rich pore channels. It achieves large evaporation rate of 2.32 kg m^-2 h^-1, voltage output of 0.33 V, and current of 7 μA under the irradiation of 1 Sun. The rich pore channels, large specific surface area, and abundant functional groups are proven as crucial factors for the generation of electricity, which are indispensable to promote high voltage output. Furthermore, the radial distribution function analysis reveals the formation mechanism of voltage, that is, more Na⁺ in solution migrate directionally under the traction of negative charges derived from functional groups in the nanochannels. This study provides a novel method for the green synthesis of porous carbon nanomaterials and contributes to the development of multi-functional evaporators for freshwater-electricity co-generation.