Accelerated Chemical Thermodynamics of Uranium Extraction from Seawater by Plant‐Mimetic Transpiration

Abstract

The extraction of uranium from seawater, which is an abundant resource, has attracted considerable attention as a viable form of energy-resource acquisition. The two critical factors for boosting the chemical thermodynamics of uranium extraction from seawater are the availability of sufficient amounts of uranyl ions for supply to adsorbents and increased interaction temperatures. However, current approaches only rely on the free diffusion of uranyl ions from seawater to the functional groups within adsorbents, which largely limits the uranium extraction capacity. Herein, inspired by the mechanism of plant transpiration, a plant-mimetic directional-channel poly(amidoxime) (DC-PAO) hydrogel is designed to enhance the uranium extraction efficiency via the active pumping of uranyl ions into the adsorbent. Compared with the original PAO hydrogel without plant-mimetic transpiration, the uranium extraction capacity of the DC-PAO hydrogel increases by 79.33% in natural seawater and affords the fastest reported uranium extraction average rate of 0.917 mg g −1 d −1 among the most state-of-the-art amidoxime group-based adsorbents, along with a high adsorption capacity of 6.42 mg g −1 within 7 d. The results indicate that the proposed method can enhance the efficiency of solar-transpiration-based uranium extraction from seawater, particularly in terms of reducing costs and saving processing time.

Plant-Mimetic Vertical-Channel Hydrogels for Synergistic Water Purification and Interfacial Water Evaporation

“…Compared to PH and PCH-0, PCH-1 presents a lower PL intensity, indicating a lower electron−hole recombination rate in PCH-1. 38,39 Overall, the combination of PPy and CN endows the PCH-1 hydrogel with the improved catalytic property, consistent with the result of catalytic experiments (Figure 7a).…”

“…As expected, the PCH-1 hydrogel without a vertical channel achieves a much lower TC degradation efficiency of 68.6% compared with samples with vertically aligned channels. The dramatic difference is supposed to be caused by the enhanced mass transfer and diffusion of pollutants in the PCH-1 hydrogel with vertical channels …”

“…Typically, the semiconductive CN is activated by visible light inducing the electron transfer from the valence band to the conduction band (Figure S7), leading to the formation of ·O 2 – and 1 O 2 . There are a few possible routes for the formation of ·OH. ,,− Importantly, PPy nanoparticles can greatly broaden the light absorption range of PCH- x , since they absorb full-spectrum light (Figure S8a) and generate a local heat source . Instantaneously, the photothermal heating is conducted to the photocatalytic active sites on adjacent CN, activating the electron–hole pair and accelerating the degradation kinetics (Figure d) .…”

“…The dramatic difference is supposed to be caused by the enhanced mass transfer and diffusion of pollutants in the PCH-1 hydrogel with vertical channels. 38 To reveal the mechanism on the high photocatalytic degradation efficiency of TC using PCH-1 hydrogel, we measured the photocatalytic properties of PPy, CN, and PC-1 powder. The transient photocurrent response of samples is presented in Figure 7b.…”

Oak-inspired anti-biofouling shape-memory unidirectional scaffolds with stable solar water evaporation performance

“…[1][2][3][4] Among various strategies, biomimetic synthesis to mimic the natural biological structure has played important roles in preparing advanced photothermal nanomaterials and assemblies for solar evaporation. For example, wood-derived scaffold 5,6 and wood-mimic aerogels 7,8 display high-performance solar evaporation, which were beneficial to water transport by utilizing or mimicking the natural vertically aligned channels in plants. Moreover, inspired by the natural structure of shaddock, 9 water lily, 10 pitcher plant 11 and mushrooms, 12 materials with advantages in thermal management, water directional transport and light capture have also promoted the enhancement in water evaporation rates.…”