In a recent article published in Advanced Sensor Research, researchers explored the utilization of Platinum Decorated Palladium Nanowires for Room-Temperature Hydrogen Detection.
The research aims to develop efficient and cost-effective sensors for hydrogen detection, which are crucial for various applications, such as safety monitoring in hydrogen-based systems.
Study: Platinum-Decorated Palladium Nanowires Enhance Hydrogen Detection. Image Credit: Tum ZzzzZ/Shutterstock.com
Background
Hydrogen gas detection plays a critical role in various industrial and environmental applications, including safety monitoring in hydrogen-based systems, leak detection, and hydrogen fuel cell technology.
Palladium nanowires (Pd NWs) have emerged as promising materials for hydrogen sensing due to their high sensitivity and selectivity towards hydrogen gas at room temperature. However, to enhance the performance of Pd NW-based sensors and enable efficient detection of low concentrations of hydrogen, novel strategies are required.
Palladium nanowires (Pd NWs) play a significant role in hydrogen sensing due to their high sensitivity to hydrogen gas. The study focuses on enhancing the sensing properties of Pd NWs by decorating them with platinum nanoparticles (Pt NPs) to improve their performance in detecting low concentrations of hydrogen at room temperature.
The Current Study
The Pd NWs were synthesized using a one-pot hydrothermal method. Initially, a solution containing PdCl2, polyvinylpyrrolidone (PVP), NaI, and acetonitrile was mixed and stirred overnight to form a homogeneous solution. This solution was then subjected to hydrothermal treatment, forming high aspect ratio Pd NWs.
To prepare Pd@Pt NWs, the synthesized Pd NWs were dispersed in ethylene glycol, followed by the addition of platinum nitrate (Pt(NO3)2). The mixture was stirred overnight to ensure uniform dispersion of Pt NPs on the Pd NWs. Subsequently, the Pd@Pt NWs were centrifuged to separate them from the solution.
The Pd@Pt NWs were drop-cast onto a paper substrate to form a conductive network. The paper substrate provided a porous and flexible platform for sensor fabrication, enhancing the interaction between the analyte (hydrogen) and the sensing material. The sensors were then heated at 200°C for 7 hours to ensure the NWs' adhesion to the paper substrate.
To eliminate ligands and improve contact between the NWs and the analyte, the fabricated sensors were exposed to an ozone-generating ultraviolet (UV-O) light source for 16 hours. This treatment degraded the surfactants on the NW surface, enhancing the sensor's response to hydrogen gas.
Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to analyze the morphology and composition of the Pd@Pt NW sensors.
Energy dispersive x-ray spectroscopy (EDS) was employed to confirm the presence of Pt on the NWs. X-ray diffraction (XRD) was utilized to determine the crystallinity of the Pd NWs and Pd@Pt NWs.
Results and Discussion
The TEM images revealed the high aspect ratio and well-defined structure of the synthesized Pd NWs. The presence of fringes corresponding to (111) planes of Pd confirmed the crystalline nature of the NWs. A core-shell morphology was observed upon decoration with platinum NPs, with a uniform distribution of small Pt NPs around the Pd NW core. This core-shell structure is crucial for enhancing the catalytic activity of the sensors.
The SEM images displayed interconnected networks of Pd@Pt NWs on the paper substrate. The porous nature of the paper substrate facilitated the formation of a conductive network, enabling efficient hydrogen sensing. A comparison with conventional interdigitated electrode (IDE)--based sensors highlighted the advantages of paper-based sensors in terms of flexibility and cost-effectiveness.
The EDS spectrum confirmed the presence of platinum on the Pd@Pt NW sensors. The elemental composition analysis revealed the successful decoration of Pd NWs with Pt NPs, further supporting the core-shell structure observed in the TEM images.
The carbon and oxygen signals detected in the EDS spectra were attributed to the paper substrate, indicating the effective integration of the NWs with the substrate.
The XRD patterns of the Pd@Pt NWs and Pd NWs demonstrated the crystalline nature of the materials. The comparison with standard Pd crystal structures validated the crystallographic properties of the synthesized NWs. The presence of Pt did not significantly alter the crystal structure of the Pd NWs, indicating a successful decoration process without compromising the integrity of the Pd lattice.
Conclusion
The research demonstrates the successful fabrication of Pd@Pt NW paper-based sensors for room-temperature hydrogen detection.
The study highlights the importance of substrate choice in sensor performance, emphasizing the advantages of paper-based sensors for their low cost, flexibility, and environmental friendliness. The findings pave the way for the development of efficient and scalable hydrogen sensors for various applications.
Journal Reference
Kumar A., Zhao Y., et al. (2024). Platinum Decorated Palladium Nanowires for Room-Temperature Hydrogen Detection. Advanced Sensor Research 2400013. DOI: 10.1002/adsr.202400013, https://onlinelibrary.wiley.com/doi/full/10.1002/adsr.202400013