전기방사된 1차원 PVP/TiO2 다공성 나노섬유의 광촉매 분해 연구
Photocatalystic Degradation of PVP/TiO2 Mesoprous 1-D Nanofibers Prepared by Electrospinning Process
- 저자식별ID ORCID:0000-0002-2805-6271
- 주제(키워드) 도움말 Electrospinning , TiO2 , nanofibers
- 발행기관 강릉원주대학교 일반대학원
- 지도교수 도움말 최원열
- 발행년도 2022
- 학위수여년월 2023. 2
- 학위명 석사
- 학과 및 전공 도움말 일반대학원 신소재공학과
- 세부분야 해당없음
- 실제URI http://www.dcollection.net/handler/kangnung/000000011410
- UCI I804:42001-000000011410
- 본문언어 한국어
초록/요약 도움말
As interest in the environment increases, the energy resources we consume continue to be depleted. After the industrialization stage, more energy was required along with the increase in population, and accordingly, the discovery of petroleum and fossil fuels enriched mankind. However, fossil fuels used extensively have become one of the causes of air and water pollution while generating carbon dioxide, nitrogen oxides (NOx), and sulfur oxides (Sox) as they are burned. As research on these environments progresses, it is known that TiO2, which is harmless and has excellent chemical and electrical properties, is suitable for various applications such as photocatalysts and semiconductor gas sensors. However, it has a disadvantage that commercialization is difficult due to low photoelectric conversion efficiency, and research is being conducted to find various ways to solve this problem. In this study, porous nanofibers with a large specific surface area were prepared using the electrospinning method to increase the photocatalytic efficiency by improving the surface of existing TiO2 nanofibers so that they can produce more electron carrier concentration through an increase in active sites. Mesoporous pores were obtained on the surface of conventional TiO2 nanofibers using polyvinyl pyrrolidone (PVP; K-90, K-30) and a foaming agent and surfactant diisopropyl azodicarboxylate (DIPA) with the heating rate as a variable. The morphology and crystalline properties of the TiO2 samples were analyzed using a field emission electron microscope (FE-SEM) and X-ray diffraction (XRD). In addition, the specific surface area and pore characteristics of each nanofiber sample were compared using the Brunauer-Emmett-Teller (BET) method. TiO2 nanofibers prepared by adding K-30 polyvinyl pyrrolidone and diisopropyl azodicarboxylate to the precursor showed more porosity than TiO2 nanofibers without them, and mesoporous nanofibers containing K-30 and DIPA had a higher specific surface area than TiO2 nanofibers. It was confirmed that this improved from a minimum of 38.4% to a maximum of 64%. In addition, the photolysis efficiency was up to 100%. 1-D g-C3N4/TiO2 with excellent photocatalytic performance was obtained by synthesizing g-C3N4, a material with excellent conductivity through melamine using the data of improved mesoporous TiO2, and then doping it on mesoporous TiO2 nanofibers with improved surface morphology. Successfully synthesized nanofibers. The photocatalytic adsorption rates of MB and AO7 in these materials showed up to 95.1% and 42.1% efficiency.
more초록/요약 도움말
환경에 대한 관심이 높아지는 만큼 우리가 소비하고 있는 에너지 자원은 계속 고갈되고 있다. 인류는 산업화 단계를 지나 과도기에 접어들면서 인 구의 증가와 동시에 더 많은 에너지를 필요로 하게 되었고, 그에 따라 석 유 및 화석연료의 발견은 인류를 풍요롭게 하였다. 하지만 방대하게 사용 된 화석연료는 연소되면서 이산화탄소, 질소산화물 (NOx), 유황 산화물 (Sox) 등을 생성시키면서 대기 및 수질 오염의 원인 중 하나가 되었다. 이 러한 환경에 대한 연구가 진행됨에 따라 무해하고, 우수한 화학적 및 전기 적 특성을 가지는 TiO2는 광촉매, 반도체 가스 센서 등으로 다양한 응용 분야에 적합하다고 알려져 있다. 하지만 광전 변환효율이 낮아 상용화가 어렵다는 단점을 가지고 있어, 이를 해결하기 위해 다양한 방안을 찾는 연 구가 진행되고 있다. 본 연구는 기존의 TiO2 나노 섬유의 표면을 개선하여 활성 부위의 증가를 통해 더 많은 전자 캐리어 농도를 생산할 수 있도록 하여 광촉매 효율을 높이기 위해 전기방사법을 사용하여 비표면적이 넓은 다공성 나노 섬유를 제조하였다. polyvinyl pyrrolidone (PVP; K-90, K-30) 와 열처리 승온 속도를 변수로 거품제 및 계면 활성제 Diisopropyl azodicarboxylate (DIPA)를 사용하여 기존의 TiO2 나노 섬유의 표면에 mesoporous 기공을 얻을 수 있었다. Field emission electron microscope (FE-SEM)과 X-ray diffraction (XRD)을 이용하여 TiO2 시료들의 형태 및 결정한적 특성을 분석하였다. 또한 Brunauer-Emmett-Teller (BET) 방법 을 사용하여 각 나노 섬유 샘플의 비표면적 및 기공 특성을 비교하였다. 전구체에 K-30 polyvinyl pyrrolidone과 Diisopropyl azodicarboxylate를 첨가하여 제조한 TiO2 나노 섬유는 이들이 없는 TiO2 나노 섬유보다 더 많은 다공성을 보였고, K-30과 DIPA를 포함하는 mesoporous 나노 섬유 는 TiO2 나노섬유에 비해 비표면적이 최소 38.4 %에서 최대 64 %까지 향 상된 것을 확인하였다. 또한 광분해 효율 최대 100% 보였다. 개선된 mesoporous TiO2의 데이터를 활용하여 melamine을 통하여 전도 성이 뛰어난 소재인 g-C3N4를 합성한 후, 표면의 형태가 개선된 mesoporous TiO2 나노 섬유에 dopent하여 광촉매 성능이 우수한 1-D g- C3N4/TiO2 나노 섬유 합성하였다. 이러한 소재의 MB와 AO7의 광촉매 분해율은 최대 95.1 %와 42.1 % 효 율 보여주었다.
more목차 도움말
I. 서론 ···························································································· 6 page
II. 문헌 연구 ···················································································· 9 page
2.1 Photocatalyst ····································································· 9 page
2.2 Mesoporous materials ························································ 19 page
2.3 Electrospinning method ······················································ 23 page
Ⅲ. 실험 방법 ··················································································· 27 page
3.1 Fabricated nanofibers
1) TiO2 nanofibers synthesis method······································· 27 page
2) Mesoporous TiO2 nanofibers synthesis method ···················· 28 page
3) g-C3N4 TiO2 nanofibers synthesis method ··························· 31 page
3.2 Morphology & structure analysis
1) FE-SEM analysis ······························································ 32 page
2) TGA analysis ··································································· 33 page
3) FT-IR analysis ································································· 34 page
4) XRD analysis ···································································· 35 page
5) BET analysis ··································································· 36 page
3.3 Photocatalytic degradation test
1) Methylene blue & Acid orange 7 ········································ 37 page
IV. 실험결과 ···················································································· 38 page
4.1 TiO2 nanofibers
1) FE-SEM ·········································································· 38 page
2) XRD ················································································ 40 page
3) BET tset ········································································· 41 page
4) Photocatalytic degradation test ·········································· 42 page
4.2 Mesoporous TiO2 nanofibers
1) FE-SEM ·········································································· 45 page
2) TGA ··············································································· 59 page
3) FT-IR ············································································· 60 page
4) XRD ················································································ 61 page
5) BET tset ········································································· 63 page
6) Photocatalytic degradation test ·········································· 65 page
4.3 g-C3N4 TiO2 nanofibers
1) FE-SEM ·········································································· 68 page
2) XRD ················································································ 70 page
3) Photocatalytic degradation test ·········································· 72 page
5. Comparison of UV irradiation degradation rates ······················ 74 page
V. 결론 ··························································································· 78 page
Ⅵ. Refernce ···················································································· 80 page
