Enhanced H2 sensing performance of Pd-modified ZnO nanorods under visible light excitation

Abstract

High-performance room-temperature hydrogen (H2) sensors are the optimal choice for practical applications. Light excitation, especially visible light, is safer and requires less power compared to ultraviolet (UV) light. This makes it an effective method for achieving room temperature operation. In this study, different mass ratios of Pd-modified ZnO nanorods were synthesized using a combination of hydrothermal and impregnation methods, and their sensing performance to H2 under visible light excitation was investigated. Material characterization results demonstrated that the localized surface plasmon resonance (LSPR) effect of Pd broadened the absorption in the visible light region, increasing the generation of high-energy hot electrons. Notably, the 2.5 wt% Pd/ZnO exhibited excellent sensing performance towards 5000 ppm H2 at room temperature under visible light excitation, with a high response value of 5906.78. The LSPR effect and the catalytic activity of Pd nanoparticles significantly enhance the sensing performance of H2. Based on our current knowledge, there have been no explicit reports on the detection of H2 using visible light excitation with Pd/ZnO, thus highlighting a new direction for the study of room temperature H2 sensors.