Chinh Van Tran

Porous mixed-phase 1T/2H MoS ₂ nanofibers built by hydrothermal synthesis plus electrospinning degrade 89.60% of rhodamine B in 120 min under simulated sunlight and show a stable binder-free photoelectrochemical response on FTO.

In this study, nano-zero-valent iron (nZVI) was successfully synthesized via a green method using Cleistocalyx operculatus leaf extract as a natural reducing and capping agent. The synthesized nZVI was characterized by XRD, SEM-EDS, FT-IR, and BET. The XRD pattern confirmed the formation of crystalline α-Fe⁰, while SEM images revealed spherical aggregates in the 50-100 nm size range. FT-IR analysis identified organic functional groups from the plant extract on the nanoparticle surface, indicating bio-capping. BET analysis showed a specific surface area of 67.484 m2/g with a mixed micro-mesoporous structure. Batch experiments revealed that while nZVI alone primarily adsorbed Rhodamine B (RhB) and H₂O₂ alone exhibited limited oxidation, the combined nZVI/H₂O₂ system achieved nearly complete decolorization within 50 min. The enhanced efficiency was attributed to a heterogeneous Fenton-like process generating highly reactive ·OH radicals. These findings demonstrate that Cleistocalyx operculatus-mediated nZVI offers a sustainable and effective approach for the removal of organic dyes from wastewater, highlighting its potential in advanced water treatment applications.

In this paper, Fe2O3/TiO2 adsorbent granules were fabricated via a drum-type granulation method with bentonite as a binder. The granulation process included three steps: mixing Fe2O3/TiO2 mixture of powder and fine coal dust into a homogeneous mixture, granulating by spraying water mist, drying the beads, and calcining at 500 oC for 1 h to form pores. The characteristic structures of composite materials after fabrication are evaluated by various methods, such as X-ray diffraction and scanning electron microscopy with energy dispersive X-ray spectroscopy. The performance evaluation of the fabricated adsorbent granulation for removing Pb2+ from polluted water was studied using a fixed-bed adsorption column. The factors affecting the adsorption performance, such as height of the adsorption column, flow rate, and inlet Pb2+ concentration, were determined. In column mode, the longest exit time was 450 minutes, the saturation time was 723 minutes, and the adsorption efficiency was 78.202% at the initial concentration of 5 mg/l, column height of 16 cm, and flow rate of 5 ml/min. The adsorption data with three well-established fixed-bed adsorption models, namely the Adam-Bohart, Thomas, and Yoon-Nelson models, with a correlation coefficient, R2 > 0.95.

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.

Trong thí nghiệm này đã nghiên cứu biến tính nano graphene ứng dụng chế tạo mực in dẫn điện. Nano graphene sau khi được biến tính bằng axit oleic để tăng khả năng phân tán trong dung môi hữu cơ được trộn với tỉ lệ chất kết dính và dung môi phù hợp tạo thành mực in dẫn điện. Đã chế tạo thành công mẫu mực in dẫn điện trên cơ sở graphene: mực dung môi với tỉ lệ thành phần 6% bột graphene được biến tính với 2,5% axit oleic và 0,75% chất kết dính cellulose acetate butyrate hòa tan trong dung môi etyl axetat. Ở công thức mực này điện trở thấp nhất thu được là 22 Ω và điện trở suất 7,56 Ω.cm-2.

Characterizations of Fe2O3/TiO2 composites fabricated from titanium slag

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.

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.