Guangfu Qian,Tian Lu,Yunpeng Wang,Haotian Xu,Xinyu Cao,Zehan Xie,Changzhou Chen,Douyong Min
Developing high-performance catalysts is significant for hydrogen production from urea electrolysis, but is still an enormous challenge. Herein, we construct an N-induced compressive strain of Ni-MoO 2 heterostructure with a micro-nano array structure supported on nickel foam (N-Ni-MoO 2 /NF) to dramatically boost the urea electrolysis performance. In 1.0 M KOH + 0.5 M urea condition, N-Ni-MoO 2 /NF shows low potentials for urea oxidation and hydrogen evolution reaction (UOR: E 10/500/1000 = 1.351/1.415/1.439 V; HER: E − 10/ − 500/ − 1000 = − 49/−242/−284 mV). Furthermore, it can obtain 1.753 V at the high-current-output of 500 mA cm −2 for urea electrolysis and stably operate for 100 h. The good UOR/HER activity and stability of N-Ni-MoO 2 /NF are owing to the triaxial compressive strain of Ni and MoO 2 , and the heterostructure between Ni and MoO 2 , which tune the electronic structure of N-Ni-MoO 2 /NF and optimize the adsorption/desorption energy of hydrogen/urea species. Besides, the micro-nano array structure accelerates the diffusion of gas/liquid and affords more active sites to improve UOR/HER performance. Therefore, this work not only fabricates a good catalyst for urea electrolysis but also provides a promising avenue for designing high-performance non-precious-metal catalytic materials at high-current-output.
Electromagnetic hotspot engineering plays a crucial role in surface-enhanced Raman scattering (SERS) biosensors . However, the construction of optical hotspots with high density and the concentration of analytes into hotspot centers remain challenging tasks. Additionally, achieving high sensitivity and signal reproducibility in SERS biosensors is an ongoing challenge. In this study, we utilise Janus micro/nano arrays to develop a superhydrophobic SERS platform. The high roughness of these arrays facilitates the distribution of rich hotspots ranging from nano to microscale and encourages the concentration of analytes within hotspot centers. The Janus plasmonic micro/nano arrays were meticulously crafted through the synergy of site-specific growth and instant interfacial assembly of nanoparticles (NPs). In the realm of SERS measurements targeting organic dyes in river water , our sensing platform demonstrates high sensitivity (limit of detection (LOD): 10 −9 M) and signal reproducibility (relative standard deviation (RSD)=4.25 %). Furthermore, the SERS platform exhibited remarkable sensitivity to multiple dyes in river water . Thus, our superhydrophobic SERS platform lays the groundwork for sensitive analysis in diverse fields such as environmental analysis and healthcare monitoring.
危险品化学品经营许可证（带存储）