Hydrovoltaic technologies produce electricity during the interaction of water and material interfaces as a result of charge transmission in water flow, evaporation, and humidity gradients. Hydrovoltaic technologies are of growing interest as a power source for low-power devices and wearable electronics due its sustainability and reduced dependence on meteorological conditions. Here we review plant-based materials for harvesting hydrovoltaic energy with focus on mechanisms, material types, and applications. Mechanisms comprise streaming potential and the electrokinetic effect, evaporation-induced ion transport and charge separation, moisture-gradient-driven diffusion potential, and synergistic enhancement by photothermal effects. Plant materials include raw plant tissues, extracted biopolymers, natural and engineered plant-derived products. Applications comprise self-powered sensing and health monitoring, wearable and portable electronics, distributed energy harvesting and the internet of things. Devices typically deliver open-circuit voltages of 0.2–1.2 V and short-circuit currents from µA to nA, while power density generally remains in the µW-nW cm−2 range. Plant tissues and natural plant-derived materials generally deliver currents from tens of µA to nA, whereas engineered products reach currents of µA to mA. Limitations include limited power output, insufficient long-term stability, and difficulties in large-scale manufacturing. rther advances are likely to rely on the integration of multiple power-generation mechanisms, optimized material and interfacial design, standardized performance evaluation, and enhanced system-level integration.
Developing efficient room-temperature adsorbents for carbon dioxide removal in enclosed spaces is crucial for safeguarding human health and mitigating CO2 emissions. Solid amine adsorbents are promising because of their high selectivity and low regeneration energy; however, achieving fast kinetics, high capacity, and long-term stability for indoor applications remains challenging. Here we used mesoporous silica foam with an ultra-large pore structure as support for polyethylenimine, diethanolamine, aminoethylethanolamine, and diethylenetriamine. The large pore volume of mesoporous silica foam enables high amine loadings, while amino alcohols weaken polyethylenimine chain entanglement and enhance accessibility of active sites. Surface silanol (Si–OH) groups further stabilize amino alcohols via hydrogen bonding, improving cyclic durability. Consequently, the hybrid amine adsorbents exhibit markedly enhanced CO2 uptake and faster kinetics than single-amine adsorbents. Notably, the adsorbent comprising a 1:1 mass ratio of polyethylenimine and diethanolamine, achieved 177 mg/g CO2 uptake, i.e., around 70
Tap water is a major source of human exposure to per- and polyfluoroalkyl substances (PFAS), some of which are known to be carcinogenic. However, data on PFAS in bottled water remain limited. Here we report a meta-analysis of 65 PFAS, including the 20 substances regulated by the European Drinking Water Directive, in 163 bottled water samples from 34 brands across 11 countries. Results show that none of the 20 regulated PFAS was detected above the limit of quantification, and their sum was below 56 ng/L in all samples, complying with the 100 ng/L guideline value. Among the 65 PFAS, only trifluoroacetic acid, which is not included in the regulatory PFAS list, was detected. Specifically, trifluoroacetic acid was systematically found in waters from France, Belgium, and Morocco, with mean concentrations of 461 ± 322, 438 ± 178, and 74 ± 12 ng/L, respectively. In Italy, trifluoroacetic acid was detected in two water brands at 350 ± 49 and 88 ± 16 ng/L, while concentrations were lower than 50 ng/L elsewhere. These findings highlight the need to include trifluoroacetic acid in bottled water monitoring.
The coronavirus disease pandemic in 2019-2022 represented a unique event during which the abrupt reduction of human activity highly decreased atmospheric pollution by fossil carbon dioxide, yet the influence of meteorological variability such as haze-induced air stagnation is poorly known. We sampled air at an urban site in the Xi’an High-Tech Zone during the lockdown from December 23, 2021, to January 23, 2022. Fossil fuel carbon dioxide emissions were quantified by measuring carbon-13 and carbon-14 isotopic compositions of atmospheric carbon dioxide, normalized using a ventilation coefficient. We compared days of haze conditions with normal, well-ventilated days. Results show that, during the lockdown, haze conditions increased fossil carbon dioxide concentration by 159 ± 48
