1. Full name:     Nguyen Thi Quynh Anh                          2. Sex: female

3. Date of birth: 13/11/1987                                            4. Place of birth: Quang Ninh

5. Admission decision number: 2999/QĐ-ĐHKHTN, 18/08/2016, Rector of VNU University of Science.

6. Changes in academic process:

- Extension Decision of PhD time No. 567/QĐ-ĐHKHTN signed on date 14/02/2020 and No. 318/QĐ-ĐHKHTN signed on date 01/02/2021 by Rector of VNU University of Science;

 - Decision No. 3942/QĐ-ĐHKHTN date on 19/12/2022 by the Rector of VNU University of Science for sending PhD. Student back to working organisation.

7. Official thesis title:

Research on preparation of TiO2-Poly Acrylic Acid (PAA)-Graphene oxide (GO) photocatalytic materials for treating Direct Blue 71 dye in water environment

8. Major: Environmental chemistry                      9. Code: 9440112.05

10. Supervisors:   Prof. Dr. Nguyen Van Noi

                Dr. Nguyen Huu Van

11. Summary of the new findings of the thesis:

- In this study, a 3D TiO2-PAA-GO hydrogel photocatalyst was synthesized by hydrothermal method.  The PAA played a crucial role as a cross-linking agent in the fabrication of TiO2-PAA-GO. The suitable conditions for synthesizing TiO2-PAA-GO photocatalyst are as follows: PAA:GO mass percentage of 25%; TiO2:GO mass ratio of 1, hydrothermal time of 6 hours, and hydrothermal temperature of 180°C.

- The XRD, FTIR, SEM, HRTEM, EDX, UV-Vis-DRS, TGA. EIS, BET and XPS results demonstrated the formation of cross-link bond within the TiO2, GO, and PAA. The TiO2-PAA-GO has a 3D structure with a relatively rough surface and high surface area (156 m2 g−1), and TiO2 particles were uniformly distributed on GO layer.  The photocatalytic activity of TiO2-PAA-GO  was enhanced due to: (i) the reduction of  bandgap energy; (ii) decreasing electron -hole recombination; (iii) increasing oxygen vacancies; (iv) high specific surface area.

- Degradation efficiency of DB71 dye (25mg/L) with  1g/L photocatalyst dose  reached  98.26% in 90 minutes under visible light with pH 6.

- After 5 cycles of use, the TiO2-PAA-GO photocatalytist still retains a high level of photocatalytic activity, with treatment efficiency of over 90%..

12. Practical applicability, if any:

A 3D structural hydrogel TiO2-PAA-GO is easily separable from the aqueous medium, has no secondary pollution, is conveniently fabricated, exhibits good reusability, synthesized using simple. The results show the potential application of these materials for the actual treatment of printing and dyeing wastewater.

13. Further research directions, if any:

- Expanding the process of synthesizing unique and simple 3D structural materials with highly practical applications.

- Testing and investigating the application of TiO2-PAA-GO materials to treat other dyeing chemicals  and organic pollutants in water environment.

14. Thesis-related publications:

[1]. Nguyen Thi Quynh Anh, Ha Minh Ngoc, Nguyen Van Noi, Nguyen Huu Van (2023), “Enhanced Photocatalytic Degradation of Direct Blue 71 Dye Using TiO2-PAA-GO Composite in Aqueous Solution”, Materials Research Express vol. 10(5), pp. 1-15(055503).

[2]. Nguyen Thi Quynh Anh, Ha Minh Ngoc, Nguyen Van Noi, Nguyen Huu Van, Tran Quang Minh (2022), “Research on the treatment of  DB71 dye in water environment using TiO2-PAA-GO photocatalytic materials” Journal of Chemistry and Application,  Number 3 (62), pp. 40-43.

[3]. Nguyen Thi Quynh Anh, Ha Minh Ngoc, Nguyen Van Noi, Nguyen Huu Van (2022), “Research on the synthesis of TiO2-PAA-GO photocatalytic materials based on titanium dioxide, graphene oxide and polyacrylic acid”, Journal of Chemistry and Application, number 3 (62), pp. 44-48.

[4]. Nguyen Thi Quynh Anh, Nguyen Van Noi, Nguyen Huu Van (2023), “Preparation and photocatalytic activity under visible light of  TiO2-PAA-GO hydrogel”, Journal of Chemistry and Application, number 4 (67), pp. 13-16.