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Electrochemical water oxidation enables the conversion of H2O to H2O2. It holds distinct advantages to the O2 reduction reaction, which is restricted by the inefficient mass transfer and limited solubility of O2 in aqueous media. Nonetheless, most reported anodes suffer from high overpotentials (usually >1000 mV) and low selectivity. Electrolysis at high overpotentials often causes serious decomposition of peroxides and leads to declined selectivity. Herein, we report a ZnGa2O4 anode with dual active sites to improve the selectivity and resist the decomposition of peroxides. Its faradaic efficiency reaches 82% at 2.3 V versus RHE for H2O2 generation through both direct (via OH−) and indirect (via HCO3−) pathways. The percarbonate is the critical species generated through the conversion of bicarbonate at Ga-Ga dual sites. The peroxy bond is stable on the surface of the ZnGa2O4 anode, significantly improving faradaic efficiency.

We proposed a dual-band polarization-insensitive metamaterial absorber consisting of merely the square metallic patch and a continuous metallic ground separated by a middle dielectric layer. Two resonance peaks derived from `the fundamental resonance (with 97% absorbance) and the surface lattice resonance (with 99% absorbance) are realized. It is different from previous work that the dual-band response is obtained by combining two resonances of different sizes. Moreover, a first-order diffraction mode of grating predicts the resonance wavelength of the proposed absorber. The surface electromagnetic field distributions of the unit-cell structure reveal the physical origin of the dual-band absorption. Importantly, the first absorption peak results from surface lattice resonance with narrow line-width has large sensitivity perform and high-quality factor, which has significant potential in the application of the biosensors and monitoring.

Electrically controlled lateral shift by an electro-optic crystal prism is studied theoretically. The resonance point of excitation of guided-wave surface plasmon resonance (GWSPR) can be controlled by altering the refractive index of the prism. That is to say, the positions corresponding to the least reflectivity and the largest lateral shift could be conveniently modulated while the lithium niobate prism is operated in an external electric field. The maximal lateral shift is obtained at the excitation of GWSPR when the thickness of the silver film is optimized. The results of numerical simulations confirm theoretical calculation.

Large tunable lateral shift from guided wave surface plasmon resonance (GWSPR) is theoretically predicted. The dip of reflectivity and magnitude of the lateral shift can be controlled by the thickness of silver layer. The position of minimum reflection and maximum Goos-Hanchen (GH) shift can be conveniently adjusted by guided layer. The largest GH shifts at the optimal thickness of silver film can be hundreds of wavelengths when GWSPR is excited. The numerical calculation results from the Gaussian beam are in accordance with theoretical results.

With the increasing demand for small-scale photodetector devices, quantum dot–based infrared photodetectors have attracted more and more attention in the past decades. In this work, periodic metal nanohole array structures are introduced to the quantum dot infrared photodetectors to enhance the photon absorptivity performance via the surface plasmon enhancement effect in order to overcome the bottleneck of low optical absorption efficiency that exists in conventional photodetectors. The results demonstrate that the optimized metal nanohole array structures can greatly enhance the photon absorptivity up to 86.47% in the specific photodetectors, which is 1.89 times than that of conventional photodetectors without the metal array structures. The large enhancement of the absorptivity can be attributed to the local coupling surface plasmon effect caused by the metal nanohole array structures. It is believed that the study can provide certain theoretical guidance for high-performance nanoscale quantum dot–based infrared photodetectors.

Using diaryliodonium salts as the arylating reagent and copper as a catalyst, a series of triarylsulfonium salts bearing benzoyl or benzoheterocyclic moieties were synthesized and characterized by 1H NMR, 13C NMR and high-resolution mass spectrometry. The photoinitiating behavior of the triarylsulfonium salts on photopolymerization of epoxy acrylate resin (UV6104) with hexane-1,6-diyldiacrylate (HDDA) as an activated monomer was investigated. The results showed that these triarylsulfonium salts could be utilized as cationic photoinitiators in the UV-curing process. A polymerization photoinitiation mechanism has been proposed.

One-dimensional (1D) photonic crystal coupled microcavity structure containing indefinite metamaterials was investigated. The Wannier-Stark ladder (WSL) can be obtained in both the Bragg ordinary and the well-known omnidirectional band gaps by modulating widths of the cavities. The time-resolved transmission of a short pulse showed the existence of two types of optical Bloch oscillation in such structures. The transmission and the period of the oscillation are found to decrease with the increasing gradient δ.