One-dimensional (1D) piezoelectric nanostructures are attractive candidates for energy generation because of their excellent piezoelectric properties attributed to their high aspect ratios and large surface areas. Vertically grown BaTiO3 nanotube (NT) arrays on conducting substrates are intensively studied because they can be easily synthesized with excellent uniformity and anisotropic orientation. In this study, we demonstrate the synthesis of 1D BaTiO3 NT arrays on a conductive Ti substrate by electrochemical anodization and sequential hydrothermal reactions. Subsequently, we explore the effect of hydrothermal reaction conditions on the piezoelectric energy conversion efficiency of the BaTiO3 NT arrays. Vertically aligned TiO2 NT arrays, which act as the initial template, are converted into BaTiO3 NT arrays using hydrothermal reaction with various concentrations of the Ba source and reaction times. To validate the electrical output performance of the BaTiO3 NT arrays, we measure the electricity generated from each NT array packaged with a conductive metal foil and epoxy under mechanical pushings. The generated output voltage signals from the BaTiO3 NT arrays increase with increasing concentration of the Ba source and reaction time. These results provide a new strategy for fabricating advanced 1D piezoelectric nanostructures by demonstrating the correlation between hydrothermal reaction conditions and piezoelectric output performance.

Abstract
1. 서 론
2. 실험방법
    2.1. BaTiO3 나노튜브 어레이 제조
    2.2. BaTiO3 나노튜브 어레이 기반의 압전 에너지 하베스터 제작
    2.3. 생성 전압 및 전류 신호 측정
3. 결과 및 고찰
4. 결 론
References

• 이재훈(경북대학교 신소재공학부) | Jae Hoon Lee (School of Materials Science and Engineering, Kyungpook National University)
• 현동열(경북대학교 신소재공학부) | Dong Yeol Hyeon (School of Materials Science and Engineering, Kyungpook National University)
• 허동훈(경북대학교 신소재공학부) | Dong Hun Heo (School of Materials Science and Engineering, Kyungpook National University)
• 박귀일(경북대학교 신소재공학부) | Kwi-Il Park (School of Materials Science and Engineering, Kyungpook National University) Corresponding Author