Modulating intramolecular charge transfer via π-d conjugative effect in coordination polymers toward photo-thermo-electric conversion

• Published in: Applied catalysis. B, Environmental Vol. 361; p. 124604
• Main Authors: Wang, Chong, Hong, Qing-Ling, Liu, Tong, Ai, Xuan, Yu, Han, Zhan, Han-Ying, Chen, Yu, Zhang, Jing
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2025
• Subjects: Charge transfer; Conjugative effect; Photothermal material; Thermoelectric power generation; π-d Conjugated coordination polymers; Thermoelectric power generation; Photothermal material; π-d Conjugated coordination polymers; Charge transfer; Conjugative effect
• ISSN: 0926-3373
• DOI: 10.1016/j.apcatb.2024.124604

The prospect of harnessing sunlight to generate cost-effective heat and electricity presents a captivating opportunity to address water scarcity and electricity shortages. Photothermal materials with a broad absorption spectrum are indispensable for effectively harnessing solar energy and converting it into heat/electricity. Herein, we developed an intramolecular charge transfer strategy via conjugated effect to regulate solar absorption and photothermal conversion ability of M-DABDT (M = Fe/Co/Ni/Cu/Zn, DABDT = 2,5-diaminobenzene-1,4-dithiol), overcoming a common limitation of narrow absorption and low photothermal efficiency in traditional metal-organic assemblies. The density functional theory calculations reveal that altering transition metal ions induces the structural torsion of organic linkers, resulting in a significant change in dihedral angle from 89.96° to 2.57°. The structural change significantly facilitates the charge transfer and electron relaxation, ultimately promoting the conversion of light to heat. Under one sun irradiation, the maximum temperature of Fe-DABDT can reach approximately 92.5 ℃. More significantly, the integration of M-DABDT CPs and thermoelectric devices under normal solar irradiation results in an extraordinary open circuit voltage (238 mV) and maximum power density (364.5 μW m−2), processing a peak output voltage density of 76.9 V m−2 at 11:00 a.m. in the presence of outdoor sunlight. This strategy presents an avenue for developing metal-organic solar absorbers for photo-thermo-electric conversion systems. [Display omitted] •As-synthesized π-d coordination polymers M-DABDT reveal efficient utilization for full-spectrum solar energy.•Regulating intramolecular charge transfer enables distinct solar energy absorption and photothermal conversion abilities.•M-DABDT show efficient rates of solar-driven steam generation (1.504 kg m−2 h−1) and electrical energy output (238 mV).•The assembled thermoelectric device achieves a maximum output voltage of 1.23 V at 11:00 a.m. under outdoor sunlight.