We report the synthesis of SnO2/α-Fe2O3 heterostructure thin films by employing two-step processes: galvanic and chemical deposition. Fe2O3 is a narrow band gap semiconductor and has short hole diffusion length. Therefore, the photogenerated electrons and holes are not easy to separate in Fe2O3. Combining Fe2O3 to SnO2, a wide-energy-gap semiconductor having suitable valence band and conduction band position is a promising candidate for the photo catalysts. The chemical modification of this heterostructure was achieved by electro-active Prussian blue (PB) molecule. The photocatalytic activities of SnO2, α-Fe2O3, SnO2/α-Fe2O3, and SnO2/α-Fe2O3-PB thin films were investigated for organic dye degradation. It was observed that the coupled and combined modified systems showed better reactivity compared to individual single-component materials. The electrocatalytic activity of the synthesized thin films has also been studied where hydrogen peroxide (H2O2) was taken as a model compound. Amperometric study also reveals that the couple and combined modified thin films are more effective at sensing hydrogen peroxide (H2O2) than single-component materials.
A new single-source precursor, [Cu(mdpa)2][CuCl2], is used to prepare selectively high chalcocite (Cu2S) with excellent photodegradation of Congo red (CR).
A novel non-enzymatic peroxide sensor has been constructed by using nickel oxide (NiO) thin films as sensing material, which were prepared by a two-step process: (i) electrodeposition of nickel sulfide (NiS) and (ii) thermal air oxidation of as-deposited NiS to NiO. The resultant material is highly porous and comprises interconnected nanofibers. UV-Vis spectroscopy, FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM) were used for a complete characterization of nanostructured NiO thin films. Cyclic voltammetry study shows that NiO/ITO electrode facilitates the oxidation of hydrogen peroxide and exhibits excellent catalytic activity towards its sensing. The amperometric study of NiO/ITO was carried out to determine the sensitivity, linear range, detection limit of the proposed sensor. The sensor exhibits prominent electrocatalytic activity toward the oxidation of H2O2 with a wide linear range and a low detection limit. The possible use of the synthesized NiO thin films as an effective photocatalyst for the decomposition of phenol is also discussed.
Visible light induced frequency switching behavior, exhibited by the electrochemically deposited thin films of polyvinylpyrrolidone (PVP) encapsulated Ag2S nanosphere (core-shell) is shown here. A low frequency (∼40 Hz) pulse was found to be generated upon illumination with 1 Sun due to excitonic transition, which also showed good switching behavior with the “on” and “off” state of the light. Capping of the semiconductor surface by a polymer like PVP reduces the surface states and thus lowers the built in barrier height and the width of depletion region. So, the number of photo generated but non recombining electron-hole pairs (excitons) increases, which put their signature in some unique physical properties like increase in photoluminescence (PL) intensity, light induced frequency switching behavior due to free exciton generation, etc. Here, the depositions were carried out on indium tin oxide coated glass substrates from an aqueous solution of AgNO3, thioacetamide, and PVP. The films were structurally characterized using high resolution X-ray diffraction, field emission scanning electron microscopy, and high resolution transmission electron microscopic techniques. The deposited particles were regular in shape with significantly high order of size distribution. Furrier transform infrared spectroscopy confirmed the presence of PVP as the encapsulating agent. Optical characterization, viz., UV – vis – NIR and NIR-PL revealed noteworthy amount of NIR emission from the deposited material.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.