Effect of core and surface area toward hydrogen gas sensing performance using Pd@ZnO core-shell nanoparticles

Thuy T D Nguyen; Dung Van Dao; Dong-Seog Kim; Hu-Jun Lee; Sang-Yeob Oh; In-Hwan Lee; Yeon-Tae Yu

doi:10.1016/j.jcis.2020.12.017

Effect of core and surface area toward hydrogen gas sensing performance using Pd@ZnO core-shell nanoparticles

J Colloid Interface Sci. 2021 Apr:587:252-259. doi: 10.1016/j.jcis.2020.12.017. Epub 2020 Dec 14.

Authors

Thuy T D Nguyen¹, Dung Van Dao², Dong-Seog Kim¹, Hu-Jun Lee³, Sang-Yeob Oh⁴, In-Hwan Lee⁵, Yeon-Tae Yu⁶

Affiliations

¹ Division of Advanced Materials Engineering, Research Center of Advanced Materials Development, Jeonbuk National University, Jeonju 54896, Republic of Korea.
² Institute of Research and Development, Duy Tan University, Da Nang 550000, Viet Nam; Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea.
³ Department of Materials Physics and Chemistry, Graduate School of Engineering, Kyushu University, Fukuoka 819-0395, Japan.
⁴ Korea Institute of Carbon Convergence Technology, Jeonju 54896, Republic of Korea.
⁵ Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea. Electronic address: ihlee@korea.ac.kr.
⁶ Division of Advanced Materials Engineering, Research Center of Advanced Materials Development, Jeonbuk National University, Jeonju 54896, Republic of Korea. Electronic address: yeontae@jbnu.ac.kr.

PMID: 33360898
DOI: 10.1016/j.jcis.2020.12.017

Abstract

A versatile hydrogen gas sensor is fabricated using Pd@ZnO core-shell nanoparticles (CSNPs), which were synthesized through a hydrothermal route. Effect of oxidation behavior of Pd core to hydrogen sensing is also investigated for Pd@ZnO CSNPs. Accordingly, Pd@ZnO-2 sensor (core-shell sample was calcined in argon) demonstrates the best performance with respect to Pd@ZnO-1 (core-shell sample was calcined in air) and pure ZnO. It shows a much higher response (R = R_a/R_g = 22) than those of Pd@ZnO-1 (12) and pure ZnO (7) sensors with faster response and recovery times (1.4 and 7.8 min) to 100 ppm hydrogen at 350 °C. In addition, Pd@ZnO-2 sensor owns high selectivity to hydrogen among interfering target gases. Improvement can be attributed to the high content of metallic Pd⁰ species in CSNPs as calcined in argon. Thereby, a higher Pd metallic content (77%) still remains in Pd@ZnO-2 compared to Pd@ZnO-1 (56%), which in turn modulates the resistance of sensors as exposed to air and target gas, thus enhancing gas sensing activity. High BET surface area of core-shell materials provides plenty of active sites for accelerating the sensing reactions as well.

Keywords: Core-shell; Hydrogen sensing; Palladium; Surface area; Zinc oxide.