Nickel sulfide nanocrystals for electrochemical and photoelectrochemical hydrogen generation
- 주제(키워드) photoelectrochemical water splitting , electrochemical water splitting , hydrogen evolution reaction , oxygen evolution reaction , nickel sulfide , NiS , NiS1.97 , silicon nanowire
- 발행기관 고려대학교 대학원
- 지도교수 박정희
- 발행년도 2020
- 학위수여년월 2020. 8
- 학위구분 석사
- 학과 대학원 신소재화학과
- 세부전공 소재물리화학
- 원문페이지 82 p
- UCI I804:11009-000000232483
- DOI 10.23186/korea.000000232483.11009.0001178
- 본문언어 영어
- 제출원본 000046055579
초록/요약
Photoelectrochemical water splitting has been considered as the most promising technology for generating hydrogen energy. Herein, we report nickel sulfide nanocrystals (NCs) as excellent catalysts for electrochemical and solar-driven photoelectrochemical (PEC) hydrogen evolution. Two polymorphic NiS and NiS1.97 NCs were synthesized with a controlled composition, and the NiS NCs showed higher electrocatalytic activity than the NiS1.97 NCs toward the hydrogen/oxygen evolution reactions in 0.5 M H2SO4 and 1 M KOH. Photocathodes were fabricated by growing the NiS and NiS1.97 NCs directly onto Si nanowire (NW) arrays. The deposition of NiS NCs results in excellent PEC performance in both acid and alkaline electrolytes; the photocurrent is 10 mA cm2 (at 0 V vs. RHE) and the onset potential is 0.2 V. In contrast, the Si-NiS1.97 photocathode exhibits much lower photocurrent and less stability. Detailed structure analysis using X-ray photoelectron spectroscopy reveals that the NiS is more metallic than the NiS1.97 and retains the same electronic structures during the catalytic reaction. The high catalytic activity of metallic NiS NCs should be the main cause of this enhanced PEC performance, promising efficient water-splitting Si-based PEC cells.
more목차
1. Introduction 8
2. Experimental Section 12
3. Results and Discussion 15
4. Conclusions 36
5. References 38
6. Supplementary Information 45
