Ultra-sensitive H2S sensor based on sunflower-like In-doped ZnO with enriched oxygen vacancies. Issue 46 (22nd November 2022)

• Record Type: Journal Article
• Authors: Zhang, Yong-Hui; Li, Ying-Ying; Yang, Xuan-Yu; Gong, Fei-Long; Chen, Jun-Li; Xie, Ke-Feng; Zhang, Hao-Li; Fang, Shao-Ming
• Is Part Of: Physical chemistry chemical physics. Volume 24:Issue 46(2022)
• Page Start: 28530
• Page End: 28539
• Publication Date: 2022-11-22
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d2cp02539f
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : In–ZnO with oxygen vacancies exhibits a higher sensing response and a shorter recovery time for H2 S compared to ZnO. Abstract : Metal oxide sensors face the challenge of high response and fast recovery at low operating temperatures for the detection of toxic and flammable hydrogen sulfide (H2 S) gases. Herein, novel In-doped ZnO with a sunflower-like structure and tunable surface properties was rationally synthesized. The substitutional In atom in the ZnO crystal can dramatically enhance the concentration of oxygen vacancies (Ov ), the In–ZnO sites are responsible for fast recovery, and the formation of sub-stable sulfide intermediates gives rise to the high response towards H2 S. As a result, the response of the optimized 4In–ZnO sensor is 3538.36 to 50 ppm H2 S at a low operating temperature of 110 °C, which is 106 times higher than that of pristine ZnO. Moreover, the response time and recovery time to 50 ppm H2 S are 100 s and 27 s, respectively, with high selectivity and stability. First-principles calculations revealed that 4In–ZnO with rich Ov exhibited higher adsorption energy for the H2 S molecule than pristine ZnO, resulting in effortless H2 S detection. Our work lays the foundation for the rational design of highly sensitive gas sensors through precise doping of atoms in oxygen-rich vacancies in semiconductor materials.