Photocatalysis is a new advanced oxidation process based on the irradiation of semiconductors such as TiO2 and ZnO for photodegradation of contaminants. In this process, the semiconductor absorbs the photon energy of ultraviolet radiation, generating highly reactive species for the degradation of organic compounds. It has been reported that doping of transition metals (e.g., Cu, Ni, Co, and Mn) into

This review covers the recent progress made in the nanophotonic devices-based daytime passive radiative coolers. The radiative cooling capabilities along with the structural description of various natural species are discussed. The design principle along with key characteristics of the omnidirectional solar reflectors as well as thermal adiators is discussed in detail. Several analogues planner one-dimensional

We report energy transfer (ET) from two dyes: Alexa Fluor 514 (AF514) and Alexa Fluor 532 (AF532) to gold nanoparticles (AuNPs) of three different sizes (10, 30, and 53 nm) employing steady-state and time-resolved fluorescence measurements. The results show that the fluorescence intensity and fluorescence lifetimes of donor (D) molecules AF514 and AF532 decrease with increase in the concentration of

We study the near-infrared properties of spherical multishell nanoparticles comprising a loss-less dielectric core enclosed by a concentric layering of metallic–dielectric–metallic nanoshells. The coupling between the metallic shells induces plasmon resonance redshifts and peak splitting in the absorption spectra of the layered particle relative those of the metallic constituents. We use full-wave

A metallic microcones array-based plasmonic strcture is presented as an example for the purpose of experimentally exploring the dependence of ambient temperature and incident angle on resonance and absorption properties. The microcones array is fabricated using the technique of heavy ion tracking. The technique has advantages of large-area patterning, high-aspect ratio of unit dimension, controllable

In the framework of effective mass envelope function approximation, the impurity states are calculated in InGaAsP/InP core–shell quantum dots by plane wave expansion method, and the effect of electric field is considered. The impurity binding energies in 1s and 2p ± states, and the impurity transition energy between 1s state and 2p ± state are calculated and analyzed in detail with the change of shell

We design and numerically investigate an all-dielectric metasurface, constructed of four open resonant rings described by the group Cs and located with a cross-shaped resonator between them, that realizes double toroidal switching, in which switching from a toroidal dipole to a quadrupole response occurs in two separate frequency regimes. It is shown that the toroidal dipole can be dynamically switched

Quantum-dot cellular automata (QCA) is a potential upcoming nanotechnology for designing digital circuits with high performance. A subtractor is an important arithmetic circuit used in many digital circuits. An efficient multilayer full subtractor design is proposed using majority logic in QCA. The proposed design has only 53 cells and occupies a small area of about 0.03 μm2. Using the proposed subtractor

A simple, low-cost, and ecofriendly method of obtaining silver nanoparticles was obtained from AgNO3 in dilution for the first time with a habanero pepper infusion. Two sets of experiments were carried out. The samples obtained in the first experiment were analyzed by SEM and TEM. Results showed that the samples prepared using 0.001 M and 0.005 M of AgNO3 and particles with an average size of 19.3

A compact and broadband transverse electric (TE)-pass power splitter using triple-guide directional couplers (TGDCs) is proposed and analyzed in detail, where the TGDCs are formed by two outside subwavelength grating (SWG) waveguides and a central strip waveguide with segmented hybrid plasmonic waveguides (HPWs) on its top. For input transverse magnetic (TM) mode, it is transmitted along the central

Due to the dire need to monitor, sense, and control useful and harmful chemicals for industrial, environmental, and biomedical purposes, chemical sensing has become an eminent topic among researchers. Hence, we focus mainly on a modified kagome design with a relatively high sensitivity of 99.8%, effective material loss of 0.000263 cm − 1 for constant absorption loss, and 0.0004204 cm − 1 for variable

A quasicontinuously wavelength tuned self-injection locked blue laser diode system employing a prism is presented. A rigorous analysis of the injection ratio (IR) in the form of three systems, namely high (HRS, ∼ − 0.7 dB IR), medium (MRS, ∼ − 1.5 dB IR), and low (LRS, ∼ − 3.0 dB IR) reflection systems, showed a direct relationship with the wavelength tunability whereas the usable system power exhibited

The issues faced by CMOS technology in the nanoregime have led to research for other possible technologies that can operate with the same functionalities but with higher speed and lower power dissipation. One such technology is quantum-dot cellular automata (QCA). A 3 × 3 reversible universal and multifunctional gate is presented that is reversible, universal, and multifunctional in nature. The gate

We theoretically investigate the enhancement of the evanescent waves near the surface of a prism coated with several layers of metals, graphene, and double negative materials. The thicknesses of the metals and double negative material films along with the number of graphene layers are optimized to achieve the highest enhancement factor. We show that the intensity of the evanescent wave in the proposed

Tumor necrosis factor-alpha (TNF-α) is a signaling protein of inflammatory processes. TNF-α overexpression triggers inflammatory processes related to various diseases such as rheumatoid arthritis, Crohn’s disease, Chagas, and others. For this reason, the TNF-α has been used as an important biological biomarker for prognosis, understanding, and disease treatment. Surface plasmon resonance (SPR)-based

A terahertz graphene tunable absorber consisting of monolayer graphene on a dielectric grating and a substrate separated by a waveguide layer is designed and investigated. The absorber exhibits polarization-independent absorption enhancement at resonance for fully conical light incidence, which is attributed to the simultaneous excitation of two identical guided modes in the waveguide layer. Moreover

Fluorescence intensity changes were investigated theoretically and experimentally using self-assembled colloidal structures on silver semitransparent mirrors. Using a simplified quasi-static model and finite element method, we demonstrate that near-field interactions of metallic nanostructures with a continuous metallic surface create conditions that produce enormously enhanced surface plasmon resonances

Anisotropic metal-based nanomaterials have been proposed as potential contrast agents due to their strong surface plasmon resonance. We evaluated the contrast properties of gold, silver, and gold-silver hybrid nanorods for molecular imaging applications in three-dimensional biological samples. We used diffuse reflectance spectroscopy to predict the contrast properties of different types of nanorods

Analytical expressions for the plasmon resonance frequencies of prolate and oblate spheroids and their dependence on ellipticity have been derived, and approximate bounds on these frequencies established. These formulas may be useful in tuning the plasmon resonance within certain limits. With increasing aspect ratio, the prolate spheroid resonance is red shifted relative to a sphere with no lower limit