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In this study, ZrO2 and Zn–ZrO2 nanoparticles (NPs) with a series of Zn ion doping amounts were synthesized by the sol-gel process and utilized as substrates for surface-enhanced Raman scattering (SERS). After absorbing the probing molecule 4–mercaptobenzoic acid, the SERS signal intensities of Zn–ZrO2 NPs were all greater than that of the pure ZrO2. The 1% Zn doping concentration ZrO2 NPs exhibited the highest SERS enhancement, with an enhancement factor (EF) value of up to 104. X-ray diffraction, X-ray photoelectron spectroscopy, Ultraviolet (UV) photoelectron spectrometer, UV–vis spectroscopy, Transmission Electron Microscope (TEM), and Raman spectroscopy were used to characterize the properties of Zn–ZrO2 NPs and explore the mechanisms behind the SERS phenomenon. The charge transfer (CT) process is considered to be responsible for the SERS performance of 4–MBA adsorbed on Zn–ZrO2. The results of this study demonstrate that an appropriate doping ratio of Zn ions can promote the charge transfer process between ZrO2 NPs and probe molecules and significantly improve the SERS properties of ZrO2 substrates.

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Direct observation of the surface-enhanced Raman scattering (SERS) of molecules adsorbed on nano-sized zirconia (ZrO 2 ) substrates was first reported without the need for the addition of metal particles. It was found that ZrO 2 nanoparticles can exhibit unprecedented Raman signal enhancements on the order of 10 3 for the probe molecule 4-mercaptobenzoic acid (4-MBA). The dramatic effect of the calcination temperature on the ZrO 2 nanoparticles was also investigated. The ZrO 2 nanoparticles with the particle diameter of 10.5 nm, which were prepared by calcination at a temperature of 500°C, have the highest SERS activity. A comparison between the experimental and calculation results indicates that charge transfer (CT) effects dominate the surface enhancement. The plentiful surface state of ZrO 2 active substrate that is beneficial to CT resonance occurs between molecules and ZrO 2 to produce a SERS effect. The CT process depends, to a large extent, on the intrinsic properties of the modifying molecules and the surface properties of the ZrO 2 . This is a new SERS phenomenon for ZrO 2 that will expand the application of ZrO 2 to microanalysis and is beneficial for studying the basic properties of both ZrO 2 and SERS.

Photoelectric conversion efficiency is primarily determined by the carrier transport path of the dye-sensitized solar cell (DSSC) interface. While open-circuit voltage (V OC ) is one of the important performance parameters in DSSCs, a deeper understanding of its correlation with the photogenerated carrier transport at the photoanode interface has always been a major challenge for researchers. Here, we propose an in situ Raman spectroscopy strategy for synchronously monitoring the V OC value of DSSCs to investigate the photoanode operation mechanisms by revealing electrolyte species and dye evolution at the photoanode/ electrolyte interface. TiO 2 nanoparticles are modified on TiO 2 nanotube array surfaces to improve the specific surface area of dye sensitization and, thus, regulate the V OC of DSSCs. The results confirm that fluctuations in the Raman spectral intensities of polyiodide formed at the photoanode/electrolyte interface during photosensitization are highly correlated with the V OC value. Furthermore, direct spectroscopic evidence also revealed that pentaiodide is spontaneously and reversibly regenerated under DSSC operating conditions. Finally, a semiquantitative method for measuring V OC of DSSCs using Raman spectroscopy is established. This study represents that in situ Raman spectroscopy can be used as an effective platform for precisely revealing the optimization mechanism of V OC in real-time, thereby providing evidence at the molecular level for improving the photovoltaic conversion performance of DSSCs.

The effect of intermolecular interaction of Phthalic acid (PA) and nonionic surfactants on electrodeposition was studied and the electrodeposition of tin was used as a model system. The CV curve of the electrolyte in the presence of a combination of PA and Triton X-100 (TX100) indicates that a relatively compact adlayer forms on the electrode surface and the electrodeposition of tin is inhibited very well. It is expected that the aromatic character of the hydrophobic moiety of both TX100 and PA enhance the binding interaction and the blocking effect is governed by the intermolecular interaction between PA and TX100. Scanning electron microscopic (SEM) image shows that a smooth, regular and compact deposit was obtained from the electrolyte with both PA and TX100. A relatively low carbon content of the deposit indicates that the incorporation of the additive in a deposit is strongly controlled in the presence of both PA and TX100. The possible explanation for the reduced incorporation may be proposed as the formation of the linkage of the molecules caused by intermolecular interaction between PA and TX100.

A bistatic chirp scaling algorithm (CSA) is presented to process the forward-looking bistatic synthetic aperture radar (FL-BiSAR) data. First, the double-square-root equation in the general bistatic range model can be simplified to a square-root equation, when the size of the scene is small enough. Based on the model, the range Doppler spectrum is derived. Then, a CSA is obtained. The range model is proved to be an effective proxy by a simulation.