Showing functionalized adsorbent hydrogels for water purification, covering synthesis routes, material characterization, and advanced functions including solar desalination, pollutant adsorption, antimicrobial, and environmental responsiveness.

Recent advances in experimental techniques allow for the fabrication of hybrid structures. Here, we study the electronic and molecular adsorption properties of the graphene (G)/hexagonal boron nitride (h-BN)-MXenes (Mo${}_2$C) hybrid nanosheets. We use first-principles calculations to explore the structure and electronic properties of the hybrid structures of G-2H-Mo${}_2$C and h-BN-2H-Mo${}_2$C with two different oxygen terminations of the Mo${}_2$C surface. The embedding of G or h-BN patches creates structural defects at the patch-Mo${}_2$C border and adds new states in the vicinity of the Fermi energy. Since this can be utilized for molecular adsorption and/or sensing, we investigate the ability of the G-M-O1 and BN-M-O1 hybrid structures to adsorb twelve molecules. Generally, the adsorption on the hybrid systems is significantly higher than on the pristine systems, except for N${}_2$ and H${}_2$, which are weakly adsorbed on all systems. We find that OH, NO, NO${}_2$, and SO${}_2$ are chemisorbed on the hybrid systems. COOH may be chemisorbed, or it may dissociate depending on its location at the edge between the G/h-BN and the MXene. NH${}_3$ is chemisorbed/physisorbed on the BN/G-M-O1 systems. CO, H${}_2$S, CO${}_2$, and CH${}_4$ are physisorbed on the hybrid systems. Our results indicate that the studied hybrid systems can be used for molecular filtration/sensing and catalysis.

In alignment with Saudi Arabia’s Vision 2030, the Kingdom aims to achieve one of its main environmental targets: reaching net zero emissions by 2060. This ambitious goal can be realized through Carbon Dioxide Removal (CDR) technologies, particularly Direct Air Capture (DAC), which is among the most promising solutions. DAC offers high potential for extracting Carbon Dioxide (CO₂) directly from the atmosphere and is considered sustainable, especially when powered by renewable energy rather than fossil fuels. However, the technology remains highly cost-intensive. This paper presents a techno-economic assessment of renewable energy configurations to determine the most cost-effective solutions for DAC deployment. The evaluation focuses on Net Present Cost (NPC) and Levelized Cost of Energy (LCOE) across several regions in Saudi Arabia, using the Hybrid Optimization of Multiple Energy Resources (HOMER) Pro software (version 3.18.4).

Flexible perovskite solar cells (FPSCs) hold great promise for lightweight and wearable photovoltaics, but improving their efficiency and durability under mechanical stress remains a key challenge. In this work, we fabricate and characterize flexible planar FPSCs on a polyethylene terephthalate (PET). A phenethylammonium iodide (PEAI) surface passivation layer is introduced on the perovskite to form a two-dimensional capping layer, and its impact on device performance and stability is systematically studied. The champion PEAI-passivated flexible device achieves a power conversion efficiency (PCE) of ~16–17%, compared to ~14% for the control device without PEAI. The improvement is primarily due to an increased open-circuit voltage and fill factor, reflecting effective surface defect passivation and improved charge carrier dynamics. Importantly, mechanical bending tests demonstrate robust flexibility: the PEAI-passivated cells retain ~85–90% of their initial efficiency after 700 bending cycles (radius ~5 mm), significantly higher than the ~70% retention of unpassivated cells. This work showcases that integrating a PEAI surface treatment with optimized electron (SnO₂) and hole (spiro-OMeTAD) transport layers (ETL and HTL) can simultaneously enhance the efficiency and mechanical durability of FPSCs. These findings pave the way for more reliable and high-performance flexible solar cells for wearable and portable energy applications.

Hybrid structures often possess superior properties to those of their component materials. This arises from changes in the structural or physical properties of the new materials. Here, we investigate the structural, electronic, and gas-adsorption properties of hybrid structures made from graphene/hexagonal boron nitride and 2H-molybdenum disulfide (G/BN@MoS₂) monolayers. We consider hybrid systems in which the G/BN patch is at the Mo plane (model I) and the S plane (model II). We find that the implanted hexagon of G or BN in MoS₂ alters its electronic properties: G@MoS₂ (I,II) are metallic, while BN@MoS₂ (I) is an n-type conducting and BN@MoS₂ (II) is semiconducting. We study the molecular adsorption of some diatomic gases (H₂, OH, N₂, NO, CO), triatomic gases (CO₂, NO₂, H₂S, SO₂), and polyatomic gases (COOH, CH₄, and NH₃) on our hybrid structures while considering multiple initial adsorption sites. Our results suggest that the hybrid systems may be suitable materials for some applications: G@MOS₂ (I) for oxygen reduction reactions, BN@MoS₂ (I,II) for NH₃-based hydrogen production, and G@MoS₂ (I) and BN@MoS₂ (I,II) for filtration of No, Co, SO₂, H₂S, and NO₂.