Twisted and Planar Structure-Based Phthalocyanine Derivative Materials for Highly Efficient Solar Absorption in Water Evaporation and Thermoelectric Power Generation

Phthalocyanine (Pc), as a type of organic photothermal material, has garnered significant attention owing to its potential tunable photophysical and photochemical properties. Herein, we propose a simple but efficient design strategy termed “planar core (Pc ring) + twisted periphery (AIE units)” to develop a photothermal material, TPE-14-CuPc. The results show that the introduction of a coplanar central core (Pc ring) and highly twisted peripheral rotors can effectively enhance photothermal conversion. TPE-14-CuPc exhibits a broad absorption range from 300 to 1300 nm in the solid state, with a molar extinction coefficient (ε) of 1.1 × 10 5 L·mol –1 ·cm –1 in CH 2 Cl 2, and achieves solar-thermal conversion efficiencies of 22.4% under one sun irradiation (0.1 W cm –2 ) and 24.50% under 808 nm laser irradiation, respectively. An interfacial heating evaporation system based on melamine (MA) foam loaded with TPE-14-CuPc was fabricated, achieving a solar-to-vapor efficiency of 50.77% and a water evaporation rate of 0.734 kg m –2 h –1 with the MA + TPE-14-CuPc foam in actual sunlight. In contrast, the evaporation rates of deionized water and seawater were 1.71 kg m –2 h –1 and 2.01 kg m –2 h –1 under one sun irradiation, respectively. Notably, TPE-14-CuPc-loaded cellulose paper was integrated with thermoelectric devices, generating a voltage as high as 214 mV under one sun irradiation, superior to its analogs synthesized using previous molecular strategies. These findings provide a feasible guideline for developing highly efficient small-molecule photothermal materials in water evaporation and power generation.