The project aims to research and develop some advanced materials with the potential for sensing pollution, environmental treatment, and energy conversion, ultimately aiming for a sustainable environment. To achieve this overarching goal, the project has addressed specific objectives:

1) Improving traditional material systems by employing novel fabrication methods or introducing new modifier components contributes to the enhanced economic and/or technical efficiency of these conventional materials.

2) Enhancing conventional materials through novel fabrication methods or the introduction of new promoters to improve their economic and/or technical efficiency.

3) Researching and developing new materials with enhanced activity or superior stability in comparison to conventional materials.

4) Identifying potential applications of the developed materials in areas such as gas sensors, CO2 conversion, hydrogen production from water, organic pollutant treatment, and/or disinfection.

- Theoretical results:

• Successful development of MicroLED light sources based on InGaN/GaN nanowire components coated with layers of CsPbI3, CsPbBr2I quantum dots (QDs), and Cs4PbBr6 perovskite nanoparticles. These sources exhibit luminescence across a broad spectrum from 400 to 650 nm.

• Successful development of potential catalyst systems for CO2 conversion into methane, utilizing conventional SiO2 support as well as various unconventional supports (SiC, composite of SiC-SiO2 and hydroxyapatite) and a novel promoter (Dy) in addition to the well-known Ce and Zr additives, including Dy-Ni/SiC, Dy-Ni/SiC-SiO2, Ce-Ni/HA and Zr-Ni/HA. Notably, the catalyst 0.5%Dy-10%Ni/SiC shows high activity in CO2 conversion to CH4 (80.6% conversion rate, CH4 selectivity over 99% at GHSV of 15·103 mL·g-1·h-1 and 375 °C). Additionally, a catalyst system with on-site regenerative capabilities for CO2 reforming of methanol (Dy-Ni/SiO2) has been developed.

• Successful development of a high piezoelectric activity BaTiO3 material with applications in water splitting for H2 generation, CO2 conversion to synthesis gas (CO + H2), and the generation of active water containing H2O2 and nitrate. This material also demonstrates the ability to harness mechanical energy such as stirring for degrading organic pollutants.

• Successful development of a nano-metal catalyst system on a green support - cellulose aerogel derived from corn husk (Fe3O4-ZnO@cellulose aerogel). This environmentally friendly catalyst system is effectively capable of treating recalcitrant organic pollutants, achieving over 82,4% removal of cinnamic acid in 90 min, with stable reusability after at least 5 cycles and antibacterial properties.

- Applied results: While the achieved results may not have immediate practical applications, they hold high potential for various applications, for example: (i) The method and materials capable of producing active water containing H2O2 and nitrate from water and air could find applications in hydroponics; (ii) The method of utilizing agricultural by-products/waste to create green supports holds promise for practical applications.

• Discovered a new modifying component (dysprosium) capable of significantly enhancing the activity of traditional Ni-based catalyst systems at very low modification concentrations (0.5%).

• Uncovered the mechanism behind the heightened activity of piezoelectric materials under the influence of mechanical stirring forces in an air environment.

• Proposed the optimal reduction time, temperature, active phase composition, and a optimum modifier content for a more economically and technically efficient CO2 conversion process using Ni-based catalysts.

• Developed an in-situ Temperature-Programmed CO2 (TPCO2) method to study on-site regeneration conditions for dry reforming catalysts prone to deactivation due to coke formation.

• Developed a method to generate active water containing H2O2 and nitrate from piezoelectric materials and ultrasonic energy.

• Developed a process for utilizing waste from fish bones and corn husks to create environmentally friendly catalyst carriers like hydroxyapatite and cellulose aerogel.

- Scientific papers in referred journals (list): 08

1) Nguyen Phuc Hoang Duy, Nguyen Nguyen Phuong, Le Thi Bao Ngoc, Nguyen Tri, Hong-Ha T. Nguyen, Dai-Viet N. Vo, Pham Thi Thuy Phuong (2022) “Deactivation and in-situ regeneration of Dy-doped Ni/SiO2 catalyst in CO2 reforming of methanol”, International Journal of Hydrogen Energy 48 (55), 21224-21239 (SCIE, IF 7.2)

2) Thi Thuy Van Nguyen, Nguyen Phung Anh, Thanh Gia-Thien Ho, Thi Thuy Phuong Pham, Phuc Hoang Duy Nguyen, Ba Long Do, Ha Ky Phuong Huynh, and Tri Nguyen (2022) “Hydroxyapatite Derived from Salmon Bone As Green Ecoefficient Support for Ceria-Doped Nickel Catalyst for CO2 Methanation”, ACS Omega 7, 36623–36633 (SCIE, IF 4.1)

3) Bao-Ngoc T Le, Nguyen-Phuong Nguyen, Thanh-Linh H Duong, Tri Nguyen, Tien-Cuong Hoang, Hong-Ha T Nguyen, Dai-Viet N Vo, Hoang-Duy P Nguyen, Thuy-Phuong T Pham (2023) “Optimizing dissolved gas composition in a double-bath-type sonoreactor for efficient production of ultrasonic-activated water with stable oxygen and nitrogen reactive species” Reaction Chemistry & Engineering 8, 2297-2308 (SCIE, IF 3.9)

4) Nguyen-Phuong Nguyen, Bao-Ngoc T Le, Tri Nguyen, Minh Tuan Nguyen Dinh, Hong-Ha T Nguyen, Dai-Viet N Vo, Nguyen Phuc Thanh Duy, Hoang-Duy P Nguyen, Thuy-Phuong T Pham (2023) “Fabrication of the coke-resistant and easily reducible Ni/SiC catalyst for CO2 methanation” Journal of the Energy Institute 110, 101332 (SCIE, IF 5.7)

5) Guru Prasanna, Hoang-Duy P Nguyen, Steve Dunn, Akalya Karunakaran, Frank Marken, Chris R Bowen, Bao-Ngoc T Le, Hoang-Duy Nguyen, Thuy-Phuong T Pham (2023) “Impact of stirring regime on piezocatalytic dye degradation using BaTiO3 nanoparticles” Nano Energy 116, 108794 (SCIE, IF 17.6)

6) Ngoc Doan Trang Tran, Thi Ngoc Han Che, Thi Thuy Van Nguyen, Ba Long Do, Thanh Gia-Thien Ho, Phung Anh Nguyen, Thi Thuy Phuong Pham, Nguyen Tri, Huynh Ky Phuong Ha (2023) “Fishbone derived-hydroxyapatite supported Ni-Zr nanocatalyst for CO2 methanation: Synergistic effects of support and zirconia” Arabian Journal of Chemistry 16, 105307 (SCIE, IF 6.0)

7) Boi An Tran, Minh Ty Nguyen, Thanh Quang Le, Tung Cao-Thanh Pham, Thuy-Phuong Thi Pham, Anh Tuyen Luu, Hoang-Duy Nguyen (2024) “High-performance red-emitting InGaN/AlGaN nanowire light-emitting diodes grown through porous template” Materials Science in Semiconductor Processing 169, 107894 (SCIE, IF 4.1)

8) Nguyen-Phuong Nguyen, Bao-Ngoc T. Le, Tri Nguyen, Thanh-Linh H. Duong, Hong-Ha T. Nguyen, Dai-Viet N. Vo, Tien-Thanh Nguyen, Hoang-Duy P. Nguyen, Thuy-Phuong T. Pham (2004) “Nickel catalyst supported on SiC incorporated SiO2 for CO2 methanation: Positive effects of dysprosium promoter and microwaves heating method” Fuel 363, 130939 (SCIE, IF 7.4)

- Patent application: 01

1) Pham Thi Thuy Phuong, Nguyen Phuc Hoang Duy, Hoang Tien Cuong, Nguyen Thi Thuy Van, Nguyen Tri, Duong Huynh Thanh Linh, Le Thi Bao Ngoc “Method for treating organic pollutant in water by piezoelectric materials”, patent application number - 1-2023-05704, 25/08/2023

- Education output: 02 masters

- Technological products stored at the Institute of Chemical Technology:

1) MicroLED coated with QDs perovskite; Quantity: 01 sample; Specifications: Perovskite QDs size: 2 – 7 nm, light absorption range: 400 – 600 nm; LED size: 100 – 300 μm², emission range: 400 – 620 nm.

2) Lead-free piezoelectric catalyst for energy conversion or environmental treatment; Quantity: 01 sample; Specifications: BaTiO₃ piezoelectric catalyst with the ability for CO₂ conversion, water splitting, generation of H₂O₂/nitrate-containing water, and decolorization of RhB dye.

3) Nickel-based thermal catalyst for hydrogenation of CO2; Quantity: 01 sample; Specifications: Dy-modified Ni/SiC catalyst capable of converting over 80% CO2 at GHSV of 15·103 mL·g-1·h-1 and temperature of 375 oC.

4) Nano metal oxide supported on cellulose aerogel for degradation of organic compounds; Quantity: 01 sample; Specifications: Fe3O4/ZnO@cellulose aerogel capable of removing 82.4% cinnamic acid in 90 minutes and reusable for at least 6 cycles.

5) Process for manufacturing microLED coated with QDs perovskite; Quantity: 01 process providing detailed information such as synthesis method, processing conditions (temperature and time), and composition.

6) Process for manufacturing lead-free piezoelectric catalysts for energy conversion or environmental treatment; Quantity: 01 process providing detailed information such as synthesis method, phase composition, temperature, and duration of calcination.

7) Process for manufacturing nickel-based thermal catalyst for hydrogenation of CO2; Quantity: 01 process providing detailed information such as synthesis method, catalyst composition (active phase, support, and promoter), temperature, and duration of calcination and reduction.

8) Process for manufacturing nano metal oxide supported on cellulose aerogel for degradation of organic compounds; Quantity: 01 process providing detailed information such as processing conditions of raw material; composition, temperature, and synthesis time.

The task "Research and development of advanced materials for a sustainable environment" holds paramount importance and demands attention, particularly in the current global context where environmental protection poses a significant challenge for many countries. This is especially true for nations undergoing rapid economic development, industrialization, and urbanization, as seen in the case of Vietnam. We earnestly seek continued financial support from VAST to further our research in this vital direction.