In the last few years, increasing interest from researchers and companies has been shown in the development of photocatalytic coatings for air purification and self-cleaning applications. In order to maintain the photocatalyst’s concentration as low as possible, highly active materials and/or combinations of them are required. In this work, novel photocatalytic formulations containing g-C₃N₄/TiO₂ composites were prepared and deposited in the form of coatings on a-block substrates. The obtained photocatalytic surfaces were tested for NOx and acetaldehyde removal from model air. It was found that the addition of only 0.5 wt% g-C₃N₄ towards TiO₂ content results in over 50% increase in the photocatalytic activity under visible light irradiation in comparison to pure TiO₂ coating, while the activity under UV light was not affected. The result was related to the creation of a g-C₃N₄/TiO₂ heterojunction that improves the light absorption and the separation of photogenerated electron-hole pairs, as well as to the inhibition of TiO₂ particles’ agglomeration due to the presence of g-C₃N₄ sheets.

This study explores the layer-by-layer (LBL) modification of polyacrylonitrile (PAN) hollow fibers for effective Mg²⁺/Li⁺ separation. It employs an LBL method of surface modification using polyelectrolytes, specifically aiming to enhance ion selectivity and improve the efficiency of lithium extraction from brines or lithium battery wastes, which is critical for battery recycling and other industrial applications. The modification process involves coating the hydrolyzed PAN fibers with alternating layers of positively charged polyelectrolytes, such as poly(allylamine hydrochloride) (PAH), polyethyleneimine (PEI), or poly(diallyldimethylammonium chloride) (PDADMAC) and negatively charged polyelectrolytes, such as poly(styrene sulfonate) (PSS), to form polyelectrolyte multilayers (PEMs). This study evaluates the modified membranes in Mg²⁺ and Li⁺ salt solutions, demonstrating significant improvements in selectivity for Mg²⁺/Li⁺ separation. PAH was identified as the optimal positively charged polyelectrolyte. PAN hollow fibers modified with ten bilayers of PAH/PSS achieved rejection rates of 95.4% for Mg²⁺ ions and 34.8% for Li⁺ ions, and a permeance of 0.39 LMH/bar. This highlights the potential of LBL techniques for effectively addressing the challenges of ion separation across a variety of applications.

This study explores the Layer-by-Layer (LbL) modification of PAN hollow fibers for effective Mg2+/Li⁺ separation. It employs a Layer-by-Layer (LBL) method of surface modification using polyelectrolytes, specifically aiming to enhance ion selectivity and improve the efficiency of lithium extraction from brines or lithium battery wastes, which is critical for battery recycling and other industrial applications. The modification process involves coating the hydrolysed PAN fibers with alternating layers of positively charged such as poly(allylamine hydrochloride) (PAH), polyethyleneimine (PEI), or poly(diallyldimethylammonium chloride) (PDADMAC) and negatively charged poly(styrene sulfonate) (PSS) to form polyelectrolyte multilayers (PEMs). This study evaluates the modified membranes in Mg2+ and Li⁺ salt solutions, demonstrating significant improvements in selectivity for Mg2+/Li⁺ separation. PAH was identified as the optimal positively charged polyelectrolyte. PAN hollow fibers modified with ten bilayers of PAH/PSS achieved rejection rates of 95.4% for Mg²⁺ ions and 34.8% for Li⁺ ions and permeance 0.39 LMH/bar. This highlights the potential of Layer-by-Layer (LbL) techniques in effectively addressing the challenges of ion separation across a variety of applications.

The CO2 conversion to valuable materials is a challenging way to manage pollution problems. In the present work, CO2 was used as a feedstock to synthesize solid carbon nanostructures by employing a simple magnesiothermic reduction reaction under constant gas flow in a tube furnace. It was shown that the CO2 reduction at 675 oC led to the simultaneous formation of different nanocarbon morphologies including graphene, tubular and spherical carbon nanostructures. The synthesized material was characterized using XRD analysis, Raman spectroscopy, SEM and TEM microscopies which demonstrated its good crystallinity and morphological diversity. Electrochemical tests were performed to evaluate specific capacitance and cycling stability of the prepared sample. The calculated values of ~ 325 F/g at scan rate 0.1 V/s revealed that the obtained nanostructures can be used as effective functional material for supercapactior applications.