RESUMEN
Effectively utilizing eco-friendly solar energy for desalination and wastewater purification has immense potential to overcome the global water crisis. Herein, we demonstrate a highly efficient solar vapor generator (SVG) developed via a simple morphological alteration, from a two-dimensional (2D) TiO2 film (TF) to one-dimensional (1D) TiO2 nanorods (TNRs) grown on a glassy carbon foam (CF). Given that evaporation is primarily a surface physical phenomenon, the 1D morphology of TNRs provides a higher evaporation surface area compared to their 2D counterpart. Additionally, the superhydrophilic nature of TNRs ensures an adequate supply of water to the evaporation surface via effective capillary action. Consequently, the 1D TNRs properly utilize photothermal heat, which results in a significant reduction in the convection heat loss. Owing to the synergistic effect of these characteristics, TNRs/CF acquires a high evaporation rate of â¼2.23 kg m-2 h-1 and an energy utilization efficiency of â¼67.1% under one sun irradiation. Moreover, the excellent stability, desalination, self-cleaning capabilities, and the facile fabrication method make TNRs/CF suitable for cost-effective, large-scale device application.
RESUMEN
Efficient solar vapor generation has provided a feasible way to solve the water shortage in undeveloped and arid areas. However, some photo-thermal materials need additional large-volume support materials being harmful to carry around to obtain float capacity, while suppressing the solar steam generation. Herein, the decrease approach of surface tension was presented for solving the moist-environment degradation behavior of black phosphorus (BP) nanosheets and obtaining the self-floating capacity, thus applying BP nanosheets in solar vapor generation field. With the in situ cross-linking polymerization, trichloro(1H,1H,2H,2H-perfluorooctyl) silane successfully modified BP nanosheets (F-BP). Due to the significantly decreased surface tension, F-BP nanosheets are capable of self-floating easily on water surface and spreading out spontaneously. With assistance of desirable photo-thermal conversion capacity, self-floating BP nanosheets convert the incident photon into local heat, showing excellent vapor generation performance. With simulated sun illumination (1 kW/m2), 238.7 g/m2 BP nanosheets present the evaporation rate of ~0.9437 kg/(m2·h) and efficiency of ~64.63 ± 2.3%. Meanwhile, the super-hydrophobicity successfully imparts BP nanosheets with resistance to the deterioration caused by salt precipitation. The carriable F-BP nanosheets are an ideal photo-thermal convertor to produce drinking water, successfully providing a feasible way to solve water shortage in limited condition.
RESUMEN
Solar vapor generation holds great potential for seawater desalination and wastewater treatment. Although various efficient solar absorbers have been developed to enhance the performance of solar vapor generators in recent years, their efficiency is still limited by unnecessary heat loss. In this article, a novel 3D hierarchical solar vapor generator (3DHG) was constructed with hydrophilic carbon felt. Different from interfacial solar vapor generators reported before, the porous and hydrophilic channels of 3DHG were exposed to the air directly, which probably resulted in a lower saturated vapor pressure of 3DHG. Therefore, this structure was beneficial for vapor escaping and led to lower average temperature of 3DHG than that of the surroundings at the same time owing to negligible convection loss and radiation loss of 3DHG. The highest evaporation rate (ER) of 1.56 kg m-2 h-1 and efficiency of 98.1% were obtained under 1 sun. In addition, 3DHG was also used for industry dyeing wastewater treatment and exhibited a minimum ER of 1.45 kg m-2 h-1 even after 7 days. This study presents a novel approach not only to design a solar vapor generator with high efficiency but also widens its potential application in seawater desalination and practical wastewater treatment.