Decoration of TiO2 nanotube (TNT) arrays by AuPd nanoparticles (NPs) produces a dramatic enhancement in the rate of hydrogen generation through photocatalytic water-splitting under solar illumination. XRD and TEM confirmed alloy formation in bimetallic AuPd NPs while XPS ruled out a core-shell architecture in the AuPd NPs. Well-dispersed, size-controlled AuPd NPs were formed by sequential physical vapor deposition of Au and Pd on TNTs followed by spontaneous thermal dewetting (TNT-AuPd).
View Article and Find Full Text PDFThe fluorescence quenching of carboxyl-rich g-CNnanoparticles was found to be selective to Agand Cewith a limit of detection as low as 30 pM for Agions. A solid-state thermal polycondensation reaction was used to produce g-CNnanoparticles with distinct green fluorescence and high water solubility. Dynamic light scattering indicated an average nanoparticle size of 95 nm.
View Article and Find Full Text PDFDendritic copper offers a highly effective method for synthesizing porous copper anodes due to its intricate branching structure. This morphology results in an elevated surface area-to-volume ratio, facilitating shortened electron pathways during aqueous and electrolyte permeation. Here, we demonstrate a procedure for a time- and cost-efficient synthesis routine of fern-like copper microstructures as a host for polymer-templated Si/Ge/C thin films.
View Article and Find Full Text PDFTiO nanotube arrays grown through electrochemical anodization in a formamide-based electrolyte (TNTA-FA) exhibited a whole host of unusual properties compared to nanotubes grown in the conventional ethylene glycol-based electrolyte (TNTA-EG). TNTA-FA exhibited shorter phonon lifetimes, lower lattice strain, more visible light absorption, lower work function, and a highly unusual adsorbate structure consisting of physisorbed and chemisorbed CO along with linearly adsorbed CO and various monodentate and bidentate carbonate species. The observation of adsorbed CO in the dark is highly unusual and indicates spontaneous deoxygenation of CO on the surface of TNTA-FA.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2023
As a metal-free and visible-light-responsive photocatalyst, graphitic carbon nitride (g-CN) has emerged as a new research hotspot and has attracted broad attention in the field of solar energy conversion and thin-film transistors. Liquid-phase exfoliation (LPE) is the best-known method for the synthesis of 2D g-CN nanosheets. In LPE, bulk g-CN is exfoliated in a solvent via high-shear mixing or sonication in order to produce a stable suspension of individual nanosheets.
View Article and Find Full Text PDFA new type of heavy-metal free single-element nanomaterial, called sulfur quantum dots (SQDs), has gained significant attention due to its advantages over traditional semiconductor QDs for several biomedical and optoelectronic applications. A straightforward and rapid synthesis approach for preparing highly fluorescent SQDs is needed to utilize this nanomaterial for technological applications. Until now, only a few synthesis approaches have been reported; however, these approaches are associated with long reaction times and low quantum yields (QY).
View Article and Find Full Text PDFBlended films comprising poly(butyl acrylate) (PBA)-grafted cellulose nanocrystals (CNCs) and poly(3-hexylthiophene) (P3HT), exhibited more intense photoluminescence (PL) and longer PL emission lifetimes compared to pristine P3HT films. Optical absorption and photoluminescence spectra indicated reduced torsional disorder i.e.
View Article and Find Full Text PDFWe report a unique photoanode architecture involving TiO, g-CN, and AuNPs wherein a synergistic enhancement of the photoelectrochemical (PEC) performance was obtained with photocurrent densities as high as 3 mA cm under AM1.5G 1 sun illumination. The PEC performance was highly stable and reproducible, and a photoresponse was obtained down to a photon energy of 2.
View Article and Find Full Text PDFWe present the electrical properties of zinc phthalocyanine covalently conjugated to cellulose nanocrystals (CNC@ZnPc). Thin films of CNC@ZnPc sandwiched between two gold electrodes showed pronounced hysteresis in their current-voltage characteristics. The layered metal-organic-metal sandwich devices exhibit distinct high and low conductive states when bias is applied, which can be used to store information.
View Article and Find Full Text PDFWe present a potential solution to the problem of extraction of photogenerated holes from CdS nanocrystals and nanowires. The nanosheet form of CN is a low-band-gap ( = 2.03 eV), azo-linked graphenic carbon nitride framework formed by the polymerization of melem hydrazine (MHP).
View Article and Find Full Text PDFThe harvesting of hot carriers produced by plasmon decay to generate electricity or drive a chemical reaction enables the reduction of the thermalization losses associated with supra-band gap photons in semiconductor photoelectrochemical (PEC) cells. Through the broadband harvesting of light, hot-carrier PEC devices also produce a sensitizing effect in heterojunctions with wide-band gap metal oxide semiconductors possessing good photostability and catalytic activity but poor absorption of visible wavelength photons. There are several reports of hot electrons in Au injected over the Schottky barrier into crystalline TiO and subsequently utilized to drive a chemical reaction but very few reports of hot hole harvesting.
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