In this study, we report the fabrication of graphitic carbon nitride doped zinc oxide nanocomposites, g-C₃N₄/ZnO, (Zn-Us) by using different amount of urea. They were further characterized by X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman, UV-vis, Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) techniques. The prepared nanocomposites were used as photocatalysts for the mineralization of the light sensitive dyes Methylene Blue (MB) and Rose Bengal (RB) under UV light irradiation, and corresponding photo-mechanism was proposed. Benefiting from these photocatalytic characteristics, urea derived g-C₃N₄/ZnO photocatalysts have been found to have excellent photodegradation activity against the MB and RB for 6 h and 4 h, respectively. Under the given experimental conditions, the degradation percentage of fabricated Zn-Us were shown ~90% for both model dyes. Compared to cationic MB dye, anionic RB dye is more actively degraded on the surface of prepared photocatalysts. The results obtained can be effectively used for future practical applications in wastewater treatment

Water contaminated with heavy metals constitutes an important threat. This threat is a real problem with a negative impact in some developing countries where untreated industrial effluents are used for irrigation. The present study examines heavy metals in wastewater-irrigated vegetables (apple gourd, spinach, cauliflower, sponge gourd, and coriander) water, and soil from Chenab Nagar, Chiniot, Pakistan. In particular, the metals quantified were cadmium (Cd), chromium (Cr), cobalt (Co), nickel (Ni), lead (Pb), and manganese (Mn). Among them, Cr and Co in crops irrigated -wastewater exceeded the levels recommended by the World Health Organization (WHO). In contrast, Ni, Cu, Pb, and Mn concentrations were in line with WHO standards. Compared with the limits established by the Food and Agriculture Organization of the United Nations (FAO), all the study vegetables presented higher (thus unsafe) concentrations of Cd (0.38 to 1.205 mg/Kg). There were also unsafe concentrations of Cr in coriander, sponge gourd, and cauliflower. Pb was found at an unsafe concentration (0.59 mg/Kg) in cauliflower. Conversely, Ni and Mn concentrations were below the maximum permissible limits by WHO, and FAO in all of the analyzed samples. The contamination load index (CLI) in soil, bioconcentration factor (BCF) in plants, daily intake of metals (DIM), and health risk index (HRI) have also been evaluated to estimate the potential risk to human health in that area. We have found an important risk of transitions of Pb, Cd, Cr, and Co from water/soil to the edible part of the plant. The highest HRI value associated with Cd (6.10–13.85) followed by Cr (1.25–7.67) for all vegetable samples presented them as high health risk metal contaminants. If the issue is not addressed, consumption of wastewater-irrigated vegetables will continue posing a health risk.

Ti₃C₂-MXene material, known for its strong electronic conductivity and optical properties, has emerged as a promising alternative to noble metals as a cocatalyst for the development of efficient photocatalysts used in environmental cleanup. In this study, we investigated the photodegradation of crystal-violet (CV) dye when exposed to UV light using a newly developed photocatalyst known as Ti₃C₂-MXene/NiO nanocomposite-decorated CsPbI₃ perovskite, which was synthesized through a hydrothermal method. Our research investigation into the structural, morphological, and optical characteristics of the Ti₃C₂-MXene/NiO/CsPbI₃ composite using techniques such as FTIR, XRD, TEM, SEM–EDS mapping, XPS, UV–Vis, and PL spectroscopy. The photocatalytic efficacy of the Ti₃C₂-MXene/NiO/CsPbI₃ composite was assessed by evaluating its ability to degrade CV dye in an aqueous solution under UV-light irradiation. Remarkably, the Ti₃C₂-MXene/NiO/CsPbI₃ composite displayed a significant improvement in both the degradation rate and stability of CV dye when compared to the Ti₃C₂-MXene/NiO nanocomposite and CsPbI₃ perovskite materials. Furthermore, the UV–visible absorption spectrum of the Ti₃C₂-MXene/NiO/CsPbI₃ composite demonstrated a reduced band gap of 2.41 eV, which is lower than that of Ti₃C₂-MXene/NiO (3.10 eV) and Ti₃C₂-MXene (1.60 eV). In practical terms, the Ti₃C₂-MXene/NiO/CsPbI₃ composite achieved an impressive 92.8% degradation of CV dye within 90 min of UV light exposure. We also confirmed the significant role of photogenerated holes and radicals in the CV dye removal process through radical scavenger trapping experiments. Based on our findings, we proposed a plausible photocatalytic mechanism for the Ti₃C₂-MXene/NiO/CsPbI₃ composite. This research may open up new avenues for the development of cost-effective and high-performance MXene-based perovskite photocatalysts, utilizing abundant and sustainable materials for environmental remediation.

The composite of ceria has been widely studied as an electrode material for supercapacitors applications due to its high energy density. Herein, we synthesize CeO₂/NiO nanocomposite via a hydrothermal route and explore its different aspects using various characterization techniques. The crystal structure is investigated using X-ray diffraction, Fourier transform infrared, and Raman spectroscopy. The formation of nanoflakes which combine to form flower-like morphology is observed from scanning electron microscope images. Selected area scans confirm the presence of all elements in accordance with their stoichiometric amount and thus authenticate the elemental purity. Polycrystalline nature with crystallite size 8–10 nm having truncated octahedron shape is confirmed from tunneling electron microscope images. Using X-ray photoelectron spectroscopy the different oxidation states of Ce and Ni are observed which play the role of active sites in the electrochemical performance of this nanocomposite material. Cyclic Voltammetry(CV) measurements at different scan rates and Galvanic Charge Discharge (GCD) measurements at different current densities are performed to probe the electrochemical response which revealed the potential of CeO₂/NiO nanocomposite as an electrode material for energy storage devices.