Photothermally enabled black g-C3N4 hydrogel with integrated solar-driven evaporation and photo-degradation for efficient water purification

• Published in: Separation and purification technology 2025-03, Vol.355, p.129751, Article 129751
• Main Authors: Chen, Zhouze, Kuate, Loic Jiresse Nguetsa, Zhang, Hefan, Hou, Jianhua, Wen, Huabing, Lu, Changyu, Li, Chunsheng, Shi, Weilong
• Format: Article
• Language: English
• Subjects: Black g-C3N4; Hydrogel; Photothermal-assisted; Solar-interfacial evaporation; Water purification
• ISSN: 1383-5866
• DOI: 10.1016/j.seppur.2024.129751

[Display omitted] •Unique cyano structure can be polymerized and cross-linking with the functional groups of CS, which can significantly improve the carrying capacity of the hydrogel;•Unique photothermal properties of CN-B can effectively convert solar energy into thermal energy to improve the efficiency of solar-driven seawater evaporation as well as the resistance to salt deposition;•The localized heat at the evaporation interface of CN-B/CS can promote the separation and migration of photo-generated carriers and the photothermal-assisted photo-degradation of the TC antibiotic. Utilizing solar-driven photocatalysis for the degradation of pollutants in seawater and facilitating interfacial evaporation presents a highly efficient and sustainable approach to addressing environmental pollution and freshwater scarcity. Herein, a black g-C3N4/chitosan (CN-B/CS) composite hydrogel system with synergistic photothermal-assisted photocatalytic antibiotic degradation and solar-interfacial evaporation was constructed for water purification. A series of characterization analyses demonstrated that the interfacial evaporation rate of CN-B/CS hydrogel could achieve up to 3.43 kg m-2h−1 with 3.5 wt% NaCl solution, and 82.5 % degradation of tetracycline (TC) solution (100 mg/L) could be achieved within 4 h of solar irradiation with excellent stability. This dual-function system of photothermal-assisted photodegradation and solar interface evaporation realized by CN-B based photothermal materials is used to achieve water purification from complex seawater environment, which provides a feasible and effective way to explore and realize sustainable environmental protection in the future.