Donor-Acceptor Charge Migration System of Superhydrophilic Covalent Triazine Framework and Carbon Nanotube toward High Performance Solar Thermal Conversion

The intrinsic hydrophobicity, deficient light absorption of solar energy, and the energy loss from the radiation relaxation of charges that decreases the solar-thermal conversion efficiency, have severely hindered the application of conjugated polymers in solar steam generation. Here, the construction of a donor-acceptor system constituted by a superhydrophilic covalent triazine framework (CTF) and carbon nanotube (CNT), which can enhance the water extraction and supply, was reported to effectively suppress the energy loss via controllable charge migration. The resulting donor-acceptor charge migration system could not only extend light harvesting but also increase energy conversion efficiency by decreasing undesired radiation relaxation, and hence it delivers a high performance in solar steam generation with a rate of 1.59 kg m^-2 h^-1 and a solar thermal conversion efficiency of 93.2% under 1 sun irradiation. This work provides a convenient strategy and new mechanism to improve the solar thermal conversion of the porous organic semiconductors.