Ca-Based Layered Double Hydroxides for Environmentally Sustainable Carbon Capture.

The process of carbon dioxide capture typically requires a large amount of energy for the separation of carbon dioxide from other gases, which has been a major barrier to the widespread deployment of carbon capture technologies. Innovation of carbon dioxide adsorbents is herein vital for the attainment of a sustainable carbon capture process. In this study, we investigated the electrified synthesis and rejuvenation of calcium-based layered double hydroxides (Ca-based LDHs) as solid adsorbents for CO.

Highly Selective Electrochemical Nitrate to Ammonia Conversion by Dispersed Ru in a Multielement Alloy Catalyst.

Electrochemical reduction of nitrate to ammonia (NH) converts an environmental pollutant to a critical nutrient. However, current electrochemical nitrate reduction operations based on monometallic and bimetallic catalysts are limited in NH selectivity and catalyst stability, especially in acidic environments. Meanwhile, catalysts with dispersed active sites generally exhibit a higher atomic utilization and distinct activity.

Predicting Extraction Selectivity of Acetic Acid in Pervaporation by Machine Learning Models with Data Leakage Management.

The extraction of acetic acid and other carboxylic acids from water is an emerging separation need as they are increasingly produced from waste organics and CO during carbon valorization. However, the traditional experimental approach can be slow and expensive, and machine learning (ML) may provide new insights and guidance in membrane development for organic acid extraction. In this study, we collected extensive literature data and developed the first ML models for predicting separation factors between acetic acid and water in pervaporation with polymers' properties, membrane morphology, fabrication parameters, and operating conditions.

Upscaling 3D Engineered Trees for Off-Grid Desalination.

More than 70% of the population without access to safe drinking water lives in remote and off-grid areas. Inspired by natural plant transpiration, we designed and tested in this study an array of scalable three-dimensional (3D) engineered trees made of natural wood for continuous water desalination to provide affordable and clean drinking water. The trees took advantage of capillary action in the wood xylems and lifted water more than 1 foot off the ground with or without solar irradiation.

Synergistic Effect of Metal Cations and Visible Light on 2D MoS Nanosheet Aggregation.

Aggregation significantly influences the transport, transformation, and bioavailability of engineered nanomaterials. Two-dimensional MoS nanosheets are one of the most well-studied transition-metal dichalcogenide nanomaterials. Nonetheless, the aggregation behavior of this material under environmental conditions is not well understood.

Interfacial solar vapor generation for desalination and brine treatment: Evaluating current strategies of solving scaling.

Interfacial solar vapor generation, an efficient, sustainable, and low-cost method for producing clean water, has attracted great interest for application in solar desalination and wastewater treatment. Although recent studies indicated significant enhancement of overall performance by developing photothermal materials and constructing different dimensional systems, stable evaporation performance and long-term operation of the evaporator are hindered by severe scaling issues. In this critical review, we present the latest strategies in reducing salt accumulation on the evaporator for solar desalination and brine treatment.

Correlating Interlayer Spacing and Separation Capability of Graphene Oxide Membranes in Organic Solvents.

Membranes synthesized by stacking two-dimensional graphene oxide (GO) hold great promise for applications in organic solvent nanofiltration. However, the performance of a layer-stacked GO membrane in organic solvent nanofiltration can be significantly affected by its swelling and interlayer spacing, which have not been systematically characterized. In this study, the interlayer spacing of the layer-stacked GO membrane in different organic solvents was experimentally characterized by liquid-phase ellipsometry.

Dew Point Measurement Using a Carbon-Based Capacitive Sensor with Active Temperature Control.

Laser-induced graphene (LIG) has both good electrical conductivity and three-dimensional porous structures. Here, porous graphene interdigital electrodes (IDE) were constructed as a capacitive sensor from commercial polymer films by the laser ablation process and transferred to the polydimethylsiloxane (PDMS) substrate. The graphene oxide (GO) adsorption layer was electrosprayed as a humidity sensing structure, and a Peltier device was used to control the temperature to produce the condensation of water vapors.

2D graphene oxide channel for water transport.

Layer-stacked graphene oxide (GO) membranes, in which unique two-dimensional (2D) water channels are formed between two neighboring GO nanosheets, have demonstrated great potential for aqueous phase separation. Subjects of crucial importance are to fundamentally understand the interlayer spacing (i.e.

Understanding the Aqueous Stability and Filtration Capability of MoS Membranes.

Membranes made of layer-stacked two-dimensional molybdenum disulfide (MoS) nanosheets have recently shown great promise for water filtration. At present, the reported water fluxes vary significantly, while the accountable structure and properties of MoS nanochannels are largely unknown. This paper aims to mechanistically relate the performance of MoS membranes to the size of their nanochannels in different hydration states.

Swelling of Graphene Oxide Membranes in Aqueous Solution: Characterization of Interlayer Spacing and Insight into Water Transport Mechanisms.

Graphene oxide (GO) has recently emerged as a promising 2D nanomaterial to make high-performance membranes for important applications. However, the aqueous-phase separation capability of a layer-stacked GO membrane can be significantly limited by its natural tendency to swell, that is, absorb water into the GO channel and form an enlarged interlayer spacing (d-spacing). In this study, the d-spacing of a GO membrane in an aqueous environment was experimentally characterized using an integrated quartz crystal microbalance with dissipation and ellipsometry.

Regenerable Polyelectrolyte Membrane for Ultimate Fouling Control in Forward Osmosis.

This study demonstrated the feasibility of using regenerable polyelectrolyte membranes to ultimately control the irreversible membrane fouling in a forward osmosis (FO) process. The regenerable membrane was fabricated by assembling multiple polyethylenimine (PEI) and poly(acrylic acid) (PAA) bilayers on a polydopamine-functionalized polysulfone support. The resulting membrane exhibited higher water flux and lower solute flux in FO mode (with the active layer facing feed solution) than in PRO mode (with the active layer facing draw solution) using trisodium citrate as draw solute, most likely due to the unique swelling behavior of the polyelectrolyte membrane.

Organic Fouling of Graphene Oxide Membranes and Its Implications for Membrane Fouling Control in Engineered Osmosis.

This study provides experimental evidence to mechanistically understand some contradicting effects of the characteristic properties of graphene oxide (GO), such as the high hydrophilicity, negative charge, strong adsorption capability, and large surface area, on the antifouling properties of GO membranes. Furthermore, this study demonstrates the effectiveness of forming a dense GO barrier layer on the back (i.e.