Hydrogen peroxide (HO) production via oxygen (O) reduction reaction (ORR) in pure water (HO) through graphitic carbon nitrides (g-CN)-based piezo-photocatalysts is an exciting approach in many current studies. However, the low Lewis-acid properties of g-CN limited the catalytic performance because of the low O adsorption efficacy. To overcome this challenge, the interaction of g-CN precursors with various solvents are utilized to synthesize g-CN, possessing multiple nitrogen-vacant species via thermal shocking polymerization.
View Article and Find Full Text PDF2D/2D step-scheme (S-scheme) piezo-photocatalysts for the production of fine chemicals, such as hydrogen peroxide (HO), have attracted significant attention of global scientists owing to the efficiency in utilizing surface piezoelectric effects from 2D materials to overcome rapid charge recombination in photocatalytic processes. In this research, we reported the fabrication of 2D S-doped VO deposited on 2D g-CN to produce HO via the piezo-photocatalytic process with high production yields at 20.19 mmol g h, which was 1.
View Article and Find Full Text PDFAerogels are becoming a promising platform to fabricate photothermal materials for use in solar steam generation (SSG), which have remarkable application potential in solar desalination, due to their excellent thermal management, salt resistance, and considerable water evaporation rate. In this work, a novel photothermal material is fabricated by forming a suspension between sugarcane bagasse fibers (SBF) and poly(vinyl alcohol), tannic acid (TA), and Fe solutions via hydrogen bonds of hydroxyl groups. After freeze drying, the fabricated SBF aerogel-based photothermal (SBFAP) material possesses a 3D interconnected porous microstructure, which could enhance water transportation ability, reduce thermal conductivity, and quickly dissolve salt crystals on the SBFAP surface.
View Article and Find Full Text PDFA novel facile combination of precipitation and plasma discharge reaction is successfully employed for one-step synthesis of an α-FeO-FeO graphene nanocomposite (GFs). The co-existence and anchoring of hematite (α-FeO) and magnetite (FeO) nanoparticles onto a graphene sheet in the as synthesized GFs were verified by results of XRD, Raman, SEM, TEM, and XPS. HRTEM characterization was used for confirming the bonding between α-FeO/FeO nanoparticles and the graphene sheet.
View Article and Find Full Text PDFHerein, Fe-doped CN high-performance photocatalysts, synthesized by a facile and cost effective heat stirring method, were investigated systematically using powder X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) surface area measurement, X-ray photoelectron (XPS), UV-Vis diffusion reflectance (DRS) and photoluminescence (PL) spectroscopy. The results showed that Fe ions incorporated into a g-CN nanosheet in both +3 and +2 oxidation states and in interstitial configuration. Absorption edge shifted slightly toward the red light along with an increase of absorbance in the wavelength range of 430-570 nm.
View Article and Find Full Text PDFQuantum dot (QD) coupling in nanophotonics has been widely studied for various potential applications in quantum technologies. Micro-machining has also attracted substantial research interest due to its capacity to use miniature robotic tools to make precise controlled movements. In this work, we combine fluorescent QDs and magnetic nanoparticles (NPs) to realize multifunctional microrobotic structures and demonstrate the manipulation of a coupled single-photon source (SPS) in 3D space via an external magnetic field.
View Article and Find Full Text PDFThe minimization principle of the second moment of the mass distribution ( M 2 ) is responsible for the unique structure of three-dimensional clusters by using emulsion droplet evaporation. Herein we study the structure of two-dimensional clusters of colloidal particles bound at the interface of liquid droplets in the plane. We found that, differently from the three-dimensional system, the two-dimensional clusters have multiple degenerate configurations (isomers).
View Article and Find Full Text PDFIn this paper, silver (Ag) nanoclusters-loaded graphitic carbon nitride (g-C₃N₄) nanosheets are synthesized and their physical properties as well as photocatalytic activities are systematically investigated by different techniques. The existence of Ag atoms in the form of nanoclusters (NCs) rather than well-crystallized nanoparticles are evidenced by X-ray diffraction patterns, SEM images, and XPS spectra. The deposition of Ag nanoclusters on the surface of g-C₃N₄ nanosheets affect the crystal structure and slightly reduce the band gap energy of g-C₃N₄.
View Article and Find Full Text PDFWe demonstrate the fabrication of a three-dimensional (3D) polymer quadratic nonlinear (χ(2)) grating structure. By performing layer-by-layer direct laser writing (DLW) and spin-coating approaches, desired photobleached grating patterns were embedded in the guest-host dispersed-red-1/poly(methylmethacrylate) (DR1/PMMA) active layers of an active-passive alternative multilayer structure through photobleaching of DR1 molecules. Polyvinyl-alcohol and SU8 thin films were deposited between DR1/PMMA layers serving as a passive layer to separate DR1/PMMA active layers.
View Article and Find Full Text PDFWe demonstrate a promising method for fabrication of plastic microlens arrays (MLAs) with a controllable ellipticity and structure, by using the combination of multiple-exposure two-beam interference and plastic replication techniques. Multiple exposures of a two-beam interference pattern with a wavelength of 442 nm into a thick positive photoresist (AZ-4620) were used to form different two-dimensional periodic structures. Thanks to the developing effect of the positive photoresist, fabricated structures consisting of hemielliptical- or hemispherical-shaped concave holes were obtained.
View Article and Find Full Text PDFMicrolens arrays (MLAs) were fabricated based on the mass transport effect of SU-8 photoresist by a multiexposure two-beam interference technique. In particular, a direct single-step fabrication process, i.e.
View Article and Find Full Text PDFThis work demonstrates a promising method to fabricate periodic nanovein structures, which can be served as templates for fabricating photonic crystals possessing a large complete photonic bandgap. First, the fabrication of a one-dimensional grating structure connected with nanolines is demonstrated by controlling the exposure dosage of the second exposure of the two-exposure two-beam interference technique. Secondly, by using the same interference technique but setting each exposure under the same exposure dosage, two-dimensional periodic structures with nanovein connections were fabricated.
View Article and Find Full Text PDF