VNUHCM Journal of Science and Technology Development

Latest Articles

1. Natural Sciences - Research article

   Construction of SrTiO3/g-C3N4 Heterojunction for Improved Visible-Light-Driven Photocatalytic Activity toward Decomposition of Organic Pollutants in Water

   Vu T., H., T., Ton N., Q., T., Nguyen T. G. B.

   Photocatalyst-assisted artificial photosynthesis has been widely recognized as a promising approach for environmental treatment. In this work, a novel hydrothermal technique was employed to synthesize three-dimensional (3D) SrTiO₃, which was then combined with two-dimensional (2D) g-C₃N₄ via a self-assembly process to create a 2D/3D g-C₃N₄/SrTiO₃ heterojunction. The morphological characteristics and optical features of the fabricated photocatalysts were assessed using powder XRD, SEM, TEM, and UV-DRS spectroscopy. The photocatalytic activity of the obtained specimens was evaluated by monitoring the photodecomposition of methylene blue (MB), a persistent organic dye pollutant commonly found in wastewater, under visible light. The results demonstrated that the binary g-C₃N₄/SrTiO₃ hybrid semiconductor exhibited excellent photocatalytic behavior, achieving a degradation efficiency of 72% after 60 min with reaction kinetics (0.018 min⁻¹), which was nearly 1.3 and 66.25 times higher than that of g-C₃N₄ and SrTiO₃, respectively. This enhancement is ascribed to the effective creation of heterojunctions between g-C₃N₄ and SrTiO₃, which facilitate improved charge separation and transfer, thereby promoting the degradation efficiency of organic pollutants. Additionally, the photocatalyst demonstrated excellent stability and reusability over four successive cycles. Based on experimental observations, a plausible photocatalytic mechanism was proposed. These findings provide a promising route for designing efficient and durable photocatalytic materials for environmental applications.

   Published: 2025-09-223833-3839
2. Section: NATURAL SCIENCES

   Mechanistic insights into electrocatalytic carbon dioxide conversion to methane via carbon monoxide pathways on PdCo catalyst

   Son D., Thanh H., Chihaia V.

   The conversion of CO₂ into value-added products is of significant interest in mitigating greenhouse gas emissions and the global energy crisis. PdCo alloy is a promising catalyst for CO₂ conversion; however, no previous studies to date have focused on determining the reaction mechanisms and activity of the conversion of CO₂ to methane (CM conversion) on this alloy.Notably, CO poisoning is a key issue in transition metal catalysts; therefore, we focused omn CM conversion via the CO formation pathway to establish whether the hydrogenation steps of CO succeed on the PdCo alloy. Our results revealed that hydrogenation processes are feasible with small thermodynamic barriers. Additionally, we gained physical insights into the interactions between the reaction intermediates and the PdCo catalyst. I have suggested some rephrasing here to improve the tone of this sentence and clarify what topic you investigated in your study. Please check to ensure your intended meaning is preserved.

   Published: 2025-09-223823-3832
3. Natural Sciences - Research article

   Synergistic Au/Ag-based SERS platform for sensitive detection of malachite green

   Tran N., H., T., Phuong N., T., T., Nhu N., D., Q., Tran N., B., Tho L., H., Van T., T.T. Le H., V., Hoang D. V.

   Introduction: Malachite green (MG), a toxic and carcinogenic triphenylmethane dye widely used in aquaculture, has been restricted in many regions due to health and environmental concerns; however, it remains prevalent in some areas because of its low cost and strong efficacy. Although various methods have been employed to detect MG, surface-enhanced Raman scattering (SERS) offers rapid, high-sensitivity analysis by leveraging noble metal nanostructures and their localized surface plasmon resonance.
   Methods: The SERS method for detecting MG leverages the localized surface plasmon resonance
   (LSPR) of gold (Au) and silver (Ag): these noble metal nanoparticles (NPs) create ``hot spots'' that concentrate electromagnetic energy. When MG molecules are adsorbed onto the Au/Ag surface, their Raman scattering signal is significantly amplified, allowing for detection at low concentrations. By employing a multilayer structure containing Au and Ag, the LSPR effect is optimized, resulting in a higher detection efficiency compared to single-layer metal substrates.
   Results: Characterization via UV-Vis spectroscopy and XRD confirmed that Au and Ag NPs exhibit distinct plasmon absorption peaks (407 and 526 nm, respectively) and the (111) lattice plane at 2q = 38.2◦. HR-TEM and FE-SEM revealed that the Au NPs are spherical (30.46-nm diameter), and the Ag NPs measure 20 nm in diameter. SERS experiments with MG indicated that the P/Au/Ag substrate provides the highest enhancement, detecting MG down to 10−9 M.
   Conclusions: The P/Au/Ag substrate for SERS-based MG detection was successfully fabricated and characterized, achieving a detection limit of 10−9M. The robust multilayer structure, boosted by the synergy between Au and Ag, holds significant potential for trace-level detection of various contaminants in environmental monitoring and food safety.

   Published: 2025-09-183817-3822
4. Sciences of Earth and Environment - Research article

   Development a method to determine Per- and Polyfluoroalkyl substances (PFAS) in total suspended particulate matter (TSP) by UPLC-MS/MS

   Minh T.,ần Nhi T., Quyen D., Thuy P., Tuan N., Duong T., Quynh L., Duy C., Khai N., Ngan T., Phu N., Hien T.

   Per- and poly-fluoroalkyl substances (PFAS) are persistent organic pollutants in many industrial and consumer products, such as pesticides, textiles, and food packaging. Although PFAS are widely used, knowledge about their occurrence in ambient particulate matter and the associated health risks remains limited. The objective of this study was to develop a sensitive, accurate, and simple method for analysing 24 PFAS compounds in total suspended particulate matter (TSP) by HPLC-MS/MS. The target compounds included 7 perfluoroalkane sulfonic acids, 11 perfluoroalkyl carboxylic acids, and 6 perfluoroalkyl acid precursors. Various instrumental parameters were optimized, including declustering potential (DP) and collision energy (CE). The ultrasound-assisted extraction conditions for dust-bound PFAS were optimized by varying the volume of methanol (MeOH), extraction time, and temperature. The optimal condition was determined to be extraction with 4 mL of MeOH at 40 °C for 10 minutes, repeated three times. Method validation results demonstrated sub-ng/L limits of quantification (LOQs) ranging from 0.01-0.14 ng/mL, with high recoveries near the LOQs (95.5% to 114.40%) and high repeatability with %RSD values ranging from 0.1% to 12.6%. The analytical procedure was subsequently applied to assess the level of PFAS contamination in TSP samples in Ho Chi Minh City. The results showed that 22 of the 24 targeted PFAS compounds were detected in the TSP samples, highlighting the significant presence of these pollutants in the megacity.

   Published: 2025-09-183809-3816
5. Natural Sciences - Research article

   Enhanced Absorption Capacity of Carboxymethyl Cellulose-Derived Superabsorbent Polymers: The Role of Acrylic Acid and Acrylamide Ratios

   Ngo T., H., Nguyen H., L., Phan T., D., Phan T., T., M., Phan T. N.

   Biodegradable superabsorbent polymer (BioSAP) synthesized from natural polymers has potential for agricultural use because of its three-dimensional hydrophilic network, which can absorb, swell, and retain a huge amount of water and salt solution. In this study, BioSAP was prepared by graft copolymerization of acrylic acid (AA) and acrylamide (AM) to the pineapple-leaf-derived car- boxymethyl cellulose using the inverse suspension method with different AA and AM ratios. The absorbent capacity and release performance of BioSAP for water and salt solution depend strongly on the AA/AM ratio. Among these samples, BioSAP with an AA/AM molar ratio of 6 exhibited the most stable gel structure and the maximum absorbencies for distilled water and salt solutions. This may be because AA can enhance the absorption and release ability of BioSAP, while AM can improve its gel stability. In addition, the presence of AA/AM in BioSAP enhances the water retention ability of the soil, leading to an increase in the storage time of water in the soil and improving the moisture content of the soil. These findings indicate that BioSAP synthesized with this AA/AM molar ratio is suitable for agricultural fields, improving soil moisture and helping plants grow better.

   Published: 2025-09-113802-3808
6. Natural Sciences - Research article

   Effect of electrospinning parameters on the morphology of polyurethane nanofibers and their shape memory behaviors

   Nguyen T., Le L., Vu P.

   We investigated the effect of various electrospinning parameters on the morphology and average diameter of shape memory polyurethane (PU) nanofibers. The shape memory performance of an electrospun PU nanofiber mat was also studied.

   Published: 2025-09-053786-3794
7. Sciences of Earth and Environment - Research article

   Valuation of provisioning ecosystem services from tram chim national park, Dong Thap province, Vietnam

   Nguyen N., Duong H., Nguyen T., Nguyen H.

   The final report of the project on the rational use of wetland natural resources in Tram Chim National Park (TCNP) with community participation during the 2012-2016 period has provided many interesting statistical data on the total number of households exploiting resources, average income, total products obtained, types of products, estimated total revenue, etc. However, since the end of the project until now, TCNP has not updated any additional data. This article uses a survey method of farmers combined with a market-based valuation method to determine the types of resources being exploited belonging to 4 groups of provisioning service: food, fuel, medicinal plants, and decorative materials. To assess the value, the article estimates the proportion of households and the average amount of resources exploited from 70 survey questionnaires. Results achieved: (i) Type of resources: there are 11 types of resources being exploited; (ii) Exploitation rate: food - 90% of surveyed households, medicinal plants 5.5%, fuel 3.5%, and decorative materials 1.0%; (iii) Annual exploitation volume: 284.3 tons of food, 2.0 tons of fuel, 1.4 tons of medicinal plants, and 1.2 ton of decorative materials; (iv) The estimated total value is 17.94 billion VND per year, with an average of 18,1 (±2,3) million VND/household/month. The results from the article demonstrate that TCNP is still providing a significant value of resource supply to society.

   Published: 2025-09-053795-3801
8. Article

   RESEARCH AND SYNTHESIS OF POPCORN-LIKE Ag@CZZ NANOMATERIAL FOR DETECTING TEBUCONAZOLE

   Tran N., H., T., Tran N., B., Nhu N., D., Q., Anh D., T., Tho L., H., Ta H., K., T., Tran Q. N.

   Pesticide residues in food remain one of the unresolved concerns in recent years. Porous materials such as metal organic frameworks (MOFs), when combined with the localized surface plasmon resonance (LSPR) effect of silver nanoparticles (Ag NPs), enable label-free detection of analyte concentrations with high sensitivity. This approach is particularly effective in the detection of tebuconazole (TB) residues, a fungicide known for its persistence and potential health risks contributing to environmental protection and food safety.

   Published: 2025-08-203779-3785
9. Section: NATURAL SCIENCES

   Ab initio chemical kinetics of Isobutene + SiH3 reaction

   Huynh L., Tran U., Nguyen L., Le K., Mai T.

   The detailed kinetic mechanism between isobutene and SiH₃ radicals was investigated theoretically using the composite electronic structure method CBS-QB3 in conjugated with the Rice-Ramsperger-Kassel-Marcus-based master equation (RRKM-ME) rate modeling. The study reveals that the title reaction proceeds through two primary pathways: (i) addition of SiH₃ to the double bond and (ii) H-abstraction by SiH₃, leading to various products. The addition pathway forms two primary products, P3 and P4. The H-abstraction pathway results in two product channels, P1 + SiH₄ and P2 + SiH₄. Among these, the adduct P3 is identified as the most thermodynamically and kinetically favorable intermediate at T < 900 K. However, at T > 900 K, P1 and P4 gain prominence. The calculated geometrical parameters, thermodynamic properties, and kinetic data align with existing/related literature for selected species. These findings provide further mechanistic insights as well as reliable information for detailed kinetic modeling of silicon chemical vapor deposition (CVD) processes, which are of significant technological importance.

   Published: 2025-06-213770-3778
10. Editorials

    Welcome to the New Editor-in-Chief

    Pham P.

    It has been my great honor to serve as Editor-in-Chief of the Science and Technology Development Journal at Vietnam National University Ho Chi Minh City (VNU-HCM) from March 9, 2021, through April 1, 2025. During these four years, I have been enriched by many inspiring and deeply meaningful experiences, contributing to the journal’s transformation into a prominent publication both domestically and internationally. Our accomplishments thus far reflect the tireless efforts of the editorial team, editorial board members, authors, and the entire VNU-HCM community, building on the strong foundation established by generations of editors and editors-in-chief over the past 25 years. I am delighted to announce that Professor Phan Bach Thang will succeed me as the next Editor-in-Chief. Given his profound research expertise and outstanding leadership, I am confident the Science and Technology Development Journal (STDJ) will continue to flourish, ultimately earning its place in the Scopus and Web of Science databases.

    Published: 2025-03-313711