One-dimensional D-π-A conjugated polymers for photoenhanced gold recovery from e-waste

• Published in: Separation and purification technology Vol. 347; p. 127521
• Main Authors: Chen, Yi-Ru, Fan, Xiao-Yi, Wei, Hao-Feng, Liao, Lieqiang, Hu, Yuqiao, Lu, Yuehao, Wang, Xiu, Li, Yibao, Cui, Wei-Rong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 11.11.2024
• Subjects: Adsorption; Conjugated polymers; D-π-A; Gold; Photocatalysis; Gold; Conjugated polymers; D-π-A; Adsorption; Photocatalysis
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2024.127521

Large-scale incineration of e-waste will bring about severe environmental pollution. Recovery of gold from e-waste using green, efficient, low-energy, and secondary-pollution-free photocatalytic technology is recognized as one of the most promising technologies. Two-dimensional conjugated polymers are often employed for photocatalytic systems due to their structural diversity and stability. However, the efficiency of active site utilization in 2D materials still needs to be improved because the catalytic reduction centers are located in the basal layer and it is difficult for Au(III) to access them. Here, we report the first example of one-dimensional D-π-A conjugated polymers for photoenhanced gold recovery from e-waste. [Display omitted] •D-π-A 1D linear polymers is innovatively applied for photoenhanced gold recovery from e-waste.•The BTP-DET has larger dipole moment, inducing a giant built-in electric field.•The highly conjugated BTP-DET framework provides efficient charge separation and migration efficiency.•Under light irradiation, BTP-DET exhibited ultra-high gold recovery (2580.8 mg g−1). In principle, photocatalytic Au(III) reduction from e-waste using sunlight could provide a cleaner and more efficient alternative strategy to existing processes. Two-dimensional (2D) conjugated polymers are often employed for photocatalytic systems due to their structural diversity and stability. However, the efficiency of active site utilization in 2D materials still needs to be improved because the catalytic reduction centers are located in the basal layer and it is difficult for Au(III) to access them. Herein, we demonstrate the application of D-A and D-π-A type one-dimensional (1D) conjugated polymers for the photoenhanced gold recovery from electronic waste. The two synthesized 1D conjugated polymers, named BTP-DET (D-π-A type) and BTP-TDB (D-A type), exhibit a wide light absorption range and excellent chemical stability. Benefiting from the superior charge separation and migration efficiency of the D-π-A skeleton, BTP-DET exhibits a small optical band gap of 1.60 eV, which is significantly smaller than that of BTP-TDB (1.78 eV), and thus enables the extraction of the gold with a higher capacity of BTP-DET (2580.8 mg g−1) under visible light, than the BTP-TDB (2072.7 mg g−1). This work paves the way for exploring low dimensions of conjugated polymers for photocatalysis.