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Desalination through reverse osmosis (RO) membrane is one of the most popular ways. However, conventional RO membranes meet a trade-off between salt rejection and water flux which limit their comprehensive performance. In this work, sulfonated zirconium (IV)-carboxylate metal–organic framework (MOF) material UiO-66-SO3H was successfully synthesized, and thin-film nanocomposite (TFN) with UiO-66-SO3H-incorporated polyamide (PA) layer was fabricated. Angstrom-sized UiO-66-X ion transport channels with different functional groups in TFN membranes change the membrane morphology and chemistry and accelerate the penetration of water molecules while maintaining the high ion screening effect. As a result, compared to the pristine TFC membrane, the optimized TFN-UiO-66-SO3H membrane exhibited an increase in water molecules permeability to 347% and still maintained a salt rejection with ~ 94.7% under 2000 ppm NaCl solution with reverse osmosis (RO) mode, leading to a great improvement of intrinsic separation properties. The improved performance was owing to the size exclusion effect and hydrophilic nature of UiO-66-SO3H particles. What is more, the additional water migration channels through the incorporated UiO-66-SO3H nanoparticles lead to a boosting water permeation and show optimized performance for desalination. [ABSTRACT FROM AUTHOR]

Excessive discharges of chemical dyes have led to severe contamination of seawater, resulting in significant ecological damage. Thermo-osmotic energy conversion technology, which purifies wastewater and generates electricity under temperature gradients, has garnered considerable interest from researchers. However, the operational efficiency of thermo-osmotic energy conversion is inherently limited by the effective membrane area, and conventional systems typically employ flat membranes as separators, resulting in suboptimal performance for the same floorage. In this study, we introduce a novel system that combines thermo-osmotic energy conversion technology with hollow fiber membranes that possess a high effective membrane area, thereby achieving optimized performance. Driven by the temperature gradient, the water in the dye solution condenses outside the membrane and converted from vapor to liquid. The continuous accumulation of condensed water generates pressure and drives a water turbine for sustainable power generation. Our results demonstrate that at temperature gradient of 40 °C, the system can achieve the power output of 16.75 Wm−3 and the freshwater production rate of 70.29 kg m−3 h−1 under ideal conditions. This study presents a novel water-electricity co-production system based on low-grade waste heat recovery for dye solution treatment, which extends the applicability of thermo-osmotic energy conversion technology and improves its practicality. • Hollow fiber membrane combined thermal-osmosis hybrid system was proposed. • Simultaneous generation of freshwater and electricity was achieved under dye solution. • Optimal operating conditions for the system are discussed. • A theoretical model was developed to optimize water and electricity output of the system. [ABSTRACT FROM AUTHOR]

Low-grade heat energy is enormous and widely distributed around the world, but it cannot be effectively converted to electricity owing to the small temperature difference and fluctuating heat source. As a promising technology that can convert low-grade heat energy into electricity while obtaining additional freshwater, thermo-osmotic energy conversion has attracted attentions of numerous researchers. However, traditional thermo-osmotic energy conversion technologies lack the utilization of the accompanying variation in salinity gradients throughout the process. In this study, a hybrid system was presented to achieve simultaneous freshwater production and electricity generation by combining thermo-osmosis system with a salinity gradient power recovery module. Continuous operation of the thermo-osmosis system will naturally produce a range of salinity differences, which will then be converted into electricity by the salinity gradient power recovery module. Our results show that this hybrid system can optimally increase the electricity output by ∼0.99 W m−2 over the conventional thermo-osmotic energy conversion system. Overall, our research demonstrates a promising device to harvest low-grade waste heat for co-generation of electricity and freshwater. This innovative approach has the potential to broaden the application possibilities of thermo-osmosis technology. • Salinity gradient recovery combined thermal-osmosis hybrid system was proposed. • A theoretical model was developed to predict electricity output of the system. • Comparing to traditional TOEC, increasing electricity output by ∼0.99 W m−2. • Co-generation of freshwater and electricity was achieved under real seawater. [ABSTRACT FROM AUTHOR]

• A hybrid system was designed to achieve simultaneous generation of fresh water and electricity. • A water yield of 1.55 kg m-2 h−1 and an 19.5 % improvement of output power were obtained under 3-sun irradiation. • Night working mode was achieved by recycling the latent heat of condensation. • An additional 6 W m−2 peak electricity output power were obtained at night. The photovoltaic (PV) cooling system based on solar-driven interfacial water evaporation (SIWE) system can effectively reduce the temperature of PV panels and obtain fresh water, but it cannot work at night during which there is no heat source input. In this work, we proposed a novel SIWE-based PV cooling systems with optimized performance that can achieve all-day working. In this hybrid system, the heat generated by the PV panel is extracted as the form of vaporization latent heat through membrane distillation (MD). Then it transferred along with the condensation of water vapor and stored in Phase Change Material (PCM), which is used to achieve electric power generation by thermoelectric effect at night. The hybrid system can achieve an 19.5 % improvement of output power compared with that without cooling method. Additionally, a 1.55 kg m-2 h−1 fresh water output with a salt rejection rate more than 99.9 % are realized under 3-sun irradiation. At the same time, it can also achieve a peak power output of 6 W m−2 at night by the release of latent heat stored in PCM. This hybrid system may provide a new idea to broaden application scenarios of traditional SIWE-based PV cooling systems. [ABSTRACT FROM AUTHOR]