Two-dimensional (2D) materials, an electrifying family of innovative materials, have recently attracted wide attention due to their remarkable characteristics, primarily their high optical transparency, exceptional metallic conductivity, high mechanical strength, carrier mobility, tunable band gap values, and optimum work function. Interestingly, 2D-nanosheets/nanolayers (2D-NLs) might be synthesized into single/multi-layers using simple processes such as chemical vapor deposition (CVD), chemical bath deposition (CBD), and mechanical and liquid-phase exfoliation processes that simply enhance optoelectronic properties. However, the stability of 2D-NLs is one of the most significant challenges that limits their commercialization. Researchers have been focusing on the stability of 2D-NLs with the aim of developing next-generation solar cells. Easily tunable distinctive 2D-NLs that are based on the synthesis process, surface functional groups, and modification with other materials/hybrid materials thereby improve the stability of the 2D-NLs and their applicability to the hole transport layer (HTL) and the electron transport layer (ETL) in solar cells. Moreover, metal/non-metal-based dopants significantly enhance band gap ability and subsequently improve the efficacy of dye-sensitized solar cells (DSSCs). In this context, research has focused on 2D-NL-based photoanodes and working electrodes that improve the photoconversion efficiency (PCE) and stability of DSSCs. Herein, we mainly focus on synthesizing 2D-NLs, challenges during synthesis, stability, and high-performing DSSCs.

Oil leakage and organic solvent industrial accidents harm the ecosystem, especially aquatic and marine life. Oil–water separation is required to combat this issue, which substantially enhances the ecosystem and recovery of oils from water bodies. In this aspect, significant efforts have been made by scientists to develop newer composite materials that efficiently separate oils from water bodies with exceptional recyclability. Membrane filtration is an efficient option for oil–water separation due to its ability to separate oil from water without involving any chemicals. However, relatively less water permeability and a high degree of surface fouling limit their applicability. The advent of two-dimensional nanomaterials (2D-NMs) gives newer insight in developing membranes due to their exceptional characteristics like hydrophobicity/hydrophilicity, selectivity, antifouling ability, flexibility, and stability. Incorporating 2D-NMs within the polymeric membranes makes them exceptional candidates for removing oil from water. Moreover, 2D-NMs offer rapid sorption/desorption rates and boost water transportation. Additionally, 2D-NMs provide roughness that significantly enhances the fouling resistance in the polymeric membrane. This review focuses on properties of 2D-NM-based polymeric membrane and their roles in oil–water separation. We also discussed strategies to improve the oil–water separation efficiency. Finally, we discussed oil–water separation’s outlook and prospects using 2D-NM-based polymeric membranes. This review might provide new insight to the researchers who work on oil–water separation.

Oil released into the environment has become one of the foremost concerns that rigorously impact the environmental system. Therefore, there is a need to develop newer membranes, modify existing membranes, or tune the wettability of membranes. The present study focuses on the synthesis of thermo-responsive polymeric membranes based on cellulose acetate (CA) and poly(N-isopropyl acrylamide) (PNIPAM) (CA-P) produced by the electrospinning process for oil/water separation. The hydrophilicity/hydrophobicity is easily tuned by increasing the amount of PNIPAM in the electrospun CA-P fibrous membrane/mat. The electrospun CA-P fibrous membrane/mat possesses switchability in terms of hydrophilicity/hydrophobicity with increasing temperature. A higher contact angle of 122° at 50 °C was observed for the CA-P fibrous membrane/mat (1:3), indicating that a higher amount of PNIPAM loaded electrospun CA-P fibrous membrane/mat has higher hydrophobicity. The electrospun CA-P fibrous membrane/mat shows high hydrophilicity at room temperature and high hydrophobicity at higher temperatures, attributed to the switchable ability of the prepared electrospun CA-P fibrous membrane/mat. Therefore, the prepared electrospun CA-P fibrous membrane/mat has the potential ability for high-efficiency oil/water separation.

Bacterial contamination in water bodies is a severe scourge that affects human health and causes mortality and morbidity. Researchers continue to develop next-generation materials for controlling bacterial infections from water. Photo-antibacterial activity continues to gain the interest of researchers due to its adequate, rapid, and antibiotic-free process. Photo-antibacterial materials do not have any side effects and have a minimal chance of developing bacterial resistance due to their rapid efficacy. Photocatalytic two-dimensional nanomaterials (2D-NMs) have great potential for the control of bacterial infection due to their exceptional properties, such as high surface area, tunable band gap, specific structure, and tunable surface functional groups. Moreover, the optical and electric properties of 2D-NMs might be tuned by creating heterojunctions or by the doping of metals/carbon/polymers, subsequently enhancing their photo-antibacterial ability. This review article focuses on the synthesis of 2D-NM-based hybrid materials, the effect of dopants in 2D-NMs, and their photo-antibacterial application. We also discuss how we could improve photo-antibacterials by using different strategies and the role of artificial intelligence (AI) in the photocatalyst and in the degradation of pollutants. Finally, we discuss was of improving the photo-antibacterial activity of 2D-NMs, the toxicity mechanism, and their challenges.