In this study, ZnO porous nanorods were synthesised using a rotational hydrothermal process, and their performance as hydrogen sulphide (H2S) gas sensors was analysed. Compared to commercial ZnO nanoparticles and conventionally hydrothermally synthesised ZnO nanorods, the ZnO porous nanorods exhibited a more uniform structure and improved crystal growth in the (002) plane, with surfaces rich in porosity and oxygen vacancies. These structural and chemical characteristics significantly improved the sensitivity toward H2S, showing high detection performance at 250°C across various concentrations of H2S gas. Additionally, the sensor demonstrated excellent selectivity against other gases such as C2H5OH, C6H6, C7H8, and NH3. This study indicated that the rotational hydrothermal process is an effective method for developing high-performance ZnO-based gas sensors and suggests its applicability to other metal oxide materials.

1. Introduction 
2. Experimental Section 
    2.1. Synthesis of sensing materials 
    2.2. Material characteristics 
    2.3. Fabrication of sensor device and sensor system 
3. Results and Discussion 
    3.1. Morphological, structural, chemical composition analysis 
    3.2. Gas sensing tests 
    3.3. Gas sensing mechanism 
4. Conclusion 
Funding
Conflict of Interest 
Data Availability Statement 
Author Information and Contribution 
Acknowledgments
References

• 박지명(경북대학교 나노신소재공학과) | Jimyeong Park (Department of Nano & Advanced Materials Science and Engineering, Kyungpook National University, Sangju 37224, Republic of Korea)
• 김찬규(경북대학교 나노신소재공학과) | Changyu Kim (Department of Nano & Advanced Materials Science and Engineering, Kyungpook National University, Sangju 37224, Republic of Korea)
• 김민서(경북대학교 나노신소재공학과) | Minseo Kim (Department of Nano & Advanced Materials Science and Engineering, Kyungpook National University, Sangju 37224, Republic of Korea)
• 최명식(경북대학교 나노신소재공학과, 경북대학교 미래과학기술융합학부, 경북대학교 탄소중립지능형 에너지시스템 지역혁신 선도연구센터) | Myung Sik Choi (Department of Nano & Advanced Materials Science and Engineering, Kyungpook National University, Sangju 37224, Republic of Korea, School of Advanced Science and Technology Convergence, Kyungpook National University, Sangju 37224, Republic of Korea, Regional Leading Research Center for Smart Energy System, Kyungpook National University, Sangju 37224, Republic of Korea) Corresponding author
• 신지연(경북대학교 미래과학기술융합학부) | Jiyeon Shin (School of Advanced Science and Technology Convergence, Kyungpook National University, Sangju 37224, Republic of Korea)
• 이재형(경북대학교 탄소중립지능형 에너지시스템 지역혁신 선도연구센터) | Jae-Hyoung Lee (Regional Leading Research Center for Smart Energy System, Kyungpook National University, Sangju 37224, Republic of Korea)