Synergy of photothermal effect in integrated 0D Ti2O3 nanoparticles/1D carboxylated carbon nanotubes for multifunctional water purification

[Display omitted] •PDA@Ti2O3 NPs and CNTs synergistically boost the solar evaporation performance.•The concave structure enables light-trapping and recycling of convective and radiative heat.•The evaporation rate of 1.81 kg m−2 h−1with a solar steam efficiency of 92.4% was achieved.•The solar evaporator demonstrated superior ability to purify seawater and various wastewaters with high efficiency. Solar driven water evaporation is a promising clean water regeneration technology to solve the worldwide water shortage problem. The solar evaporators with efficient steam generation and multifunctional water purification capabilities are in great demand. Herein, inspired by concave mirror, a novel double-layer concave aerogel evaporator was developed by template-assisted method. In the upper layer, polydopamine modified Ti2O3 nanoparticles and carbon nanotubes were used as photothermal materials was prepared with the concave structure to gain efficient solar energy absorption and energy conversion. In the lower layer, polyvinyl alcohol and chitosan were used as substrate in a double network with not only enhanced mechanical strength and good deformation resistance, but also excellent thermal management and water transport capacity of the evaporator. The as prepared evaporator has a high water evaporation rate of 1.81 kg m−2 h−1 and high water evaporation efficiency of 92.4% under one sun irradiation. In addition, it also showed the ability to purify heavy metal ions, acid, alkali and chemical dye contaminated wastewater, and considerable outdoor water purification capacity. This work will provide new ideas for the design of new solar evaporator with excellent photothermal conversion ability, and is expected to have broad application prospects in industrial processes such as water treatment and energy conversion.