In this paper, a highly catalytic and nanosized Ag / Co 3 O 4 composite for rhodamine B ( RhB ) degradation was fabricated by using the co-precipitation method at room temperature. The Ag / Co 3 O 4 structure and catalytic properties were characterized through scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) gas-sorption measurements, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-Vis spectroscopy. The results showed that the Co 3 O 4 nanosheets prepared by hydrothermal synthesis mainly exposed (2 2 0) and (1 1 1) facets, which played an important role in determining its catalytic oxidation performance. The Co 3 O 4 nanosheets doped with Ag nanoparticles by a simple silver-mirror reaction exhibited a stable and well-dispersed property in dye solution. Compared to the Ag and Co 3 O 4 nanostructure, the Ag nanoparticles with bigger diameter (10 nm) on Co 3 O 4 surface also readily produced surface-active oxygen species and exhibited a higher catalytic activity for the degradation of RhB solution (5 mg ⋅ L -1 ) under the visible light. The kinetic constant K of Ag / Co 3 O 4 catalyst for RhB degradation reaction was evaluated to 0.02724 min -1 , which is relatively higher than those reported in the literatures.
Na Li,Gengsheng Xu,Manqing Yan,Bensong Chen,Yupeng Yuan,Chuhong Zhu
Surface-enhanced Raman scattering (SERS) spectroscopy has attracted increasing attention due to its high spectral reproducibility and unique selectivity to target molecules. Here, a facile approach is proposed to prepare Ag nanoparticles modified ZnO nanorod arrays (Ag/ZnO NR arrays). Ag nanoparticles were densely decorated on the surface of ZnO nanorods through silver mirror reaction and subsequent seed-assisted electrodeposition. The prepared Ag/ZnO NR arrays can be used as a sensitive, uniform, and repeatable SERS substrate for the rapid detection of organic dye molecules and biomolecules with concentrations higher than the corresponding limits of detection (LODs). The LODs for rhodamine 6G (R6G), 4-aminothiophenol (PATP) and adenine are calculated to be 1.0 × 10−13M, 1.6 × 10−12M and 3 × 10−11M, respectively. The enhancement factor (EF) of the SERS substrate is estimated to be as high as ~2.7 × 108when detecting 10−10M R6G. Particularly, the as-synthesized substrate exhibits high selectivity to multiple components. In addition, the fabricated Ag/ZnO NR arrays can be recycled due to their superior self-cleaning ability and can realize photocatalytic degradation of R6G in water within 1 h driven by UV light, showing that the three-dimensional recyclable SERS substrates have wide applications in environmental pollution monitoring and biomedical analysis.Keywords:surface-enhanced Raman scattering;ZnO nanorod;Ag nanoparticle;detection;silver mirror reaction;electrodeposition
Wenpeng Zhao,Yaoyao Liu,Can Zhao,Xinyi Shi,Xianqi Feng,Jun Xu,Shouguo Wang,Yumin Wu,Shouke Yan
Self-healable and stretchable conductor is of great important to next-generation smart wearable electronics. However, it is still a great challenge to fabricate stretchable conductor with fast self-healing speed, high conductivity, good fatigue-resistance and simple fabrication procedure. Here, we developed a simple strategy to fabricate self-healable conductor with conductive hierarchical Ag wrinkles through in-situ silver mirror reaction on the swelled self-healing matrix. The as-prepared conductor possesses fast self-healing speed (>98% healing efficiency with 60s, and immediately healing of electrical capability after contact), high conductivity (1900 S cm −1 ) and good fatigue-resistant capability (nearly 1000 cycles test). Benefiting from the hierarchical wrinkled structure the conductor could be used as a sensor to detect wide range of human motions.
In this study, we successfully prepared silver electrodes through a silver mirror reaction. By carefully regulating the amount of ammonia complexing agent in the silver–ammonia solution, we effectively suppressed the decomposition of the plating solution while reducing the surface roughness of silver films from 9.22 nm to 4.42 nm. The electrical conductivity of our solution-processed silver layers was nearly one order of magnitude higher than that of conventional inkjet-printed silver electrodes. When applied as source-drain electrodes in organic field-effect transistors (OFETs), these electrodes enabled devices with an average mobility of 0.13 cm 2 /(V·s) and remarkably low mobility variation of only 8.7%. Furthermore, we modified the silver electrodes through chemical platinum plating, achieving a significant 0.74 eV alteration in work function, which demonstrates the great potential of chemical plating for surface functionalization in solution-processed organic electronic devices.