Advances in two-dimensional materials for energy-efficient and molecular precise membranes for biohydrogen production

Advances in perovskite membranes for carbon capture & utilization: A sustainable approach to CO2 emissions reduction - A review

Despite agreements like the Paris Agreement, the world continues to face rising temperatures, extreme weather, and ecosystem disruptions, driven by continued use fossil fuel, agricultural emissions, and industrial activities and leading to greenhouse gas contributing to the serious fuelling climate change. Carbon capture and utilization (CCU), particularly thermochemical carbon dioxide (CO2) splitting powered by thermal energy, offers a promising solution. Perovskite-based inorganic membranes, known for their high selectivity and permeability toward various gases, efficiency, and energy-saving potential, have attracted significant interest in gas separation, production and emerged as a leading technology for carbon capture and hydrogen purification. This review explores advancements in perovskite materials, focusing on H2/CO2 separation, CO2 conversion to CO, and optimal operating conditions. It addresses key questions such as improving material performance through innovations in double and composite perovskites, enhancing oxygen removal via thermochemical or electrochemical pumps, and integrating CO2 splitting with fuel production. These strategies aim to reduce costs, boost efficiency, and provide sustainable pathways for addressing climate change.

Hydrophilic Modification of Polytetrafluoroethylene (PTFE) Capillary Membranes with Chemical Resistance by Constructing Three-Dimensional Hydrophilic Networks

Polytetrafluoroethylene (PTFE) capillary membranes, known for the great chemical resistance and thermal stability, are commonly used in membrane separation technologies. However, the strong hydrophobic property of PTFE limits its application in water filtration. This study introduces a method whereby acrylamide (AM), N, N-methylene bisacrylamide (MBA), and vinyltriethoxysilane (VTES) undergo free radical copolymerization, followed by the hydrolysis-condensation of silane bonds, resulting in the formation of hydrophilic three-dimensional networks physically intertwined with the PTFE capillary membranes. The modified PTFE capillary membranes prepared through this method exhibit excellent hydrophilic properties, whose water contact angles are decreased by 24.3-61.2%, and increasing pure water flux from 0 to 1732.7-2666.0 L/m2·h. The enhancement in hydrophilicity of the modified PTFE capillary membranes is attributed to the introduction of hydrophilic groups such as amide bonds and siloxane bonds, along with an increase in surface roughness. Moreover, the modified PTFE capillary membranes exhibit chemical resistance, maintaining the hydrophilicity even after immersion in strong acidic (3 wt% HCl), alkaline (3 wt% NaOH), and oxidative (3 wt% NaClO) solutions for 2 weeks. In conclusion, this promising method yields modified PTFE capillary membranes with great hydrophilicity and chemical resistance, presenting substantial potential for applications in the field of water filtration.

Addressing challenges with evaluating hydrogen-selective membrane performance by quadrupole mass spectrometry

Hydrogen separation using nanostructured membranes has gained research attention because of its potential to produce high-purity hydrogen by separating gases at the molecular level. Quadrupole mass spectrometry (QMS) is one method to evaluate these membranes' effectiveness in separating hydrogen from gas mixtures. However, quantifying gases in a mixture with QMS is challenging, especially when heavier gas ions interfere with a light gas ion, resulting in lower quantification accuracy. This study addresses this challenge by presenting a detailed calibration procedure that significantly improves hydrogen quantification accuracy up to a factor of 2.5. CO and CO2 were chosen as interfering gases because they are commonly released in conventional hydrogen production processes. By carefully evaluating the performance of these membranes, new opportunities for hydrogen separation may be realized.