In this work, a g-C₃N₄/porphyrin nanocomposite was fabricated through the self-assembling of monomeric Tetrakis (4-carboxyphenyl) porphyrin (TCPP) molecules with g-C₃N₄ nanomaterials. The characterizing results showed a good distribution of TCPP nanofibers with a diameter of < 100 nm and several micrometers in length on the g-C₃N₄ nanoflakes’ surfaces. The prepared g-C₃N₄/porphyrin nanocomposite had two bandgap energies of 2.38 and 2.7 eV, which could harvest a wide range of photon energy in the light spectrum, particularly in visible light. The obtained C₃N₄/TCPP nanocomposite revealed a remarkable photodegradation efficiency toward rhodamine B dyes, with a RhB removing rate of 3.3 × 10⁻² min⁻¹. The plausible mechanism for the photocatalytic performance of the g-C₃N₄/porphyrin photocatalyst for the RhB dye’s degradation was also studied and discussed.

Mixed metal oxide composites have been widely used as adsorbents for the removal of heavy metal ions from wastewater. In this work, Fe₂O₃/TiO₂ composite was sustainably prepared via the treatment of titanium slag with a low-concentration sulfuric acid solution (20%) and used for the removal of As(V) from aqueous solutions. The resulting products were characterized by X-ray diffraction (XRD), N2 adsorption−desorption, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The batch adsorption was employed to investigate the removal efficiency of the Fe₂O₃/TiO₂ adsorbent toward As(V). The Langmuir and Freundlich isotherms were plotted in order to study the adsorption process. The adsorption of As(V) on FeO₃/TiO₂ fitted well with the Freundlich isotherm model, suggesting a multilayer adsorption process with an adsorption capacity of 68.26 mg·g⁻¹. The adsorption kinetics study demonstrated that the adsorption behavior of the Fe₂O₃/TiO₂ composite for the As(V) was pseudo-second-order. With low-cost preparation and high adsorption capacity, the prepared Fe₂O₃/TiO₂ adsorbent could be used as an effective adsorbent for As(V) removal from contaminated water sources. The approach utilized in this research is viewed as a sustainable route for creating a proficient adsorbent for the purification of water.

PET, one of the most commonly used plastics, presents significant environmental challenges due to its non-biodegradable nature. To address this, we developed a sustainable method to convert PET waste into high-performance activated carbon via chemical activation with phosphoric acid (H₃PO₄). The produced activated carbon was analyzed utilizing X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), nitrogen adsorption/desorption (BET), energy-dispersive X-ray (EDX), and Raman spectroscopy. The activated carbon produced had a macroporous architecture with a substantial surface area, pore diameter, and pore volume of 655.59 m²/g, 3.389 nm, and 0.120 cm³/g, respectively. The adsorption isotherm of activated carbon for phenol conformed to the Langmuir model, signifying single-layer adsorption with a maximal capacity of 114.94 mg/g, while the kinetic adsorption adhered to the second-order model at an optimal pH of 7. The study highlights the sustainable benefits of mitigating plastic waste pollution while producing a cost-effective and eco-friendly adsorbent for water treatment applications. This research underscores the potential for recycling PET waste into valuable materials for environmental remediation.

The escalating environmental concerns regarding plastic waste necessitate innovative strategies for waste management and resource utilization. This study presented a novel approach for synthesizing high surface area activated carbon through a single-step process, using polyethylene terephthalate (PET) plastic waste as the precursor and potassium hydroxide (KOH) as the activating agent. The optimal activation conditions were established using a weight ratio of 1:1 of PET to KOH and annealing for 15 minutes at 700 oC. The conversion efficiency of PET plastic trash into activated carbon exceeded 20%. The materials underwent thorough characterization using scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, and Fourier transform infrared spectroscopy (FTIR). The activated carbon obtained has a mesoporous structure and a surface area of 1831.166 m2/g. The activated carbon-prepared plastic waste showed high removal efficiency for the organic dyes in an aqueous solution, with a maximum adsorption capacity of 131.58 mg/g. The successful transformation of plastic waste into a valuable resource underscores the importance of innovative approaches to mitigating environmental degradation. The synthesized activated carbon's efficacy in adsorption-based remediation strategies establishes its potential for addressing various pollution issues and opens new avenues for valuing plastic waste.