Novel Zn-Sn-O nanocactus with excellent transport properties as photoanode material for high performance dye-sensitized solar cells

Electrospun tin (IV) oxide nanofiber based electrochemical sensor for ultra-sensitive and selective detection of atrazine in water at trace levels

Atrazine, a class 3a carcinogen, is a pesticide of chloro triazine family and is known to severely affect the human endocrine system upon consumption. The toxic effects of atrazine cause damage not only to the humans but also to animals and plants. In lieu of the detrimental effects of atrazine on environment, it is essential to develop a sensor platform capable of its detection in water. Here, we propose ultrasensitive electrochemical detection of atrazine using electrospun SnO₂ nanofibers. In this study, the nanofibers have been characterized using Field Emission Spectroscopy, X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis-NIR spectroscopy and Fourier transform infrared spectroscopy (FTIR). Using a label-free transduction, we have detected atrazine in fairly low concentrations, with the limit of detection being 0.9 zM and the sensitivity being 4.11 (μA/μM)/cm², in a wide dynamic detection range varying from 1 zM to 1 μM. Furthermore, we have reported atrazine detection in trace levels in spiked real time water samples, which is an essential step in ensuring that the sensing platform can be deployed for practical applications. In addition to this, the sensor exhibits excellent selectivity, reasonable stability (when stored at 4 °C), and good interference-resistance.

Efficient Energy Harvesting in SnO2-Based Dye-Sensitized Solar Cells Utilizing Nano-Amassed Mesoporous Zinc Oxide Hollow Microspheres as Synergy Boosters

Finding the material characteristics satisfying most of the photovoltaic conditions is difficult. In contrast, utilization of foreign materials that can contribute to light harvesting and charge transfers in the devices is now desirable/thought-provoking. Herein, a binary hybrid photoanode utilizing nano-amassed micron-sized mesoporous zinc oxide hollow spheres (meso-ZnO HS) in conjunction with SnO₂ nanoparticles (NPs), i.e., SnO₂ NP_ZnO HS (for an optimized weight ratio (8:2)), displayed a nearly ∼4-fold increase in the efficiency (η) compared to that of bare SnO₂ nanoparticle device. Enhanced device efficacy in the composite photoanode-based device can be accredited to the dual function of nano-amassed meso-ZnO HS. Nano-amassed micron-sized ZnO HS embedded in the photoanode can increase the light-harnessing capability without sacrificing the surface area as well as optical confinement of light by multiple reflections within its cavity and enhanced light-scattering effects. Electrochemical impedance spectroscopy analysis revealed an extended lifetime of electron (τ_e) and a higher value of R _ct2 at the working electrode/dye/redox mediator interface, indicating a minimum photoinduced electron interception. The open-circuit voltage decay reveals a slower recombination kinetics of photogenerated electrons, supporting our claim that the nano-ammased meso-ZnO HS can serve as an energy barrier to the photoinjected electrons to retard the back-transfer to the electrolyte. Moreover, the improvement in the fill factors of the composite-based devices is endorsed to the facile penetration of the electrolyte through the pores of nano-amassed meso-ZnO HS, which increases the regeneration probability of oxidized dyes.

High current density cation-exchanged SnO2–CdSe/ZnSe and SnO2–CdSe/SnSe quantum-dot photoelectrochemical cells

The 9.74 mA cm⁻² current density of SnO₂–CdSe photoanode is enhanced to 19.82 and 28.40 mA cm⁻² on SnO₂–CdSe/ZnSe and SnO₂–CdSe/SnSe surface modifications, respectively, through a process of cation-exchange.

La2O3-encapsulated SnO2 nanocrystallite-based photoanodes for enhanced DSSCs performance

A SnO2 nanocrystallite-based photoanode was prepared using tin (iv) chloride and fructose via a one-pot hydrothermal method, and its structural and morphological properties were studied. Structural observations revealed tetragonal crystals of SnO2, and morphological studies confirmed the presence of spherical nanoparticulates. Furthermore, encapsulating the surface of the SnO2 photoanode (+N719 dye) with thin layers of La2O3 significantly improved the short-circuit current density, open-circuit voltage, fill factor and power conversion efficiency values from 8.30 to 13.70 mA cm(-2), 0.40 to 0.46 V, 49% to 48% and 1.66% to 3.0%, respectively. The nearly two-fold improvement in energy conversion efficiency was attributed to: (a) increased dye molecules caused by the formation of strong co-ordination bonds between the dye molecules and the lanthanide, (b) enhanced photoelectron transfer rate between the dye molecules and SnO2 conduction band, and (c) negative shift of SnO2 conduction band position in the presence of La2O3 (confirmed from the Mott-Schottky and Tafel measurements).

V N, S S. α-Bi2O3 photoanode in DSSC and study of the electrode–electrolyte interface

Photoanode activity of nanoparticles of α-Bi₂O₃ in a DSSC is checked with two different dyes by considering the attachment of the dye on to the metal oxide surface and its effects on back recombination at the electrode–electrolyte interface.

Nanostructure-based optoelectronic sensing of vapor phase explosives--a promising but challenging method

Optoelectronic sensing of gas phase hazardous chemicals is a newly explored field, which shows great advantages towards low concentration sensing when compared to normal gas sensing in the dark. Here, based on the recent progress on nanostructured vapor phase explosive gas sensors operated in dark conditions, the attractiveness of developing optoelectronic sensors for vapor phase explosive detection was highlighted. Furthermore, we try to propose some new insights to enhance optoelectronic sensing of vapor phase explosives. We suggest employing photocatalysis principles to enhance the sensitivity and employing a molecular imprinting technique (MIT) to enhance the selectivity.

Recent Advances in SnO2 Based Photo Anode Materials for Third Generation Photovoltaics

Dye Sensitized Solar Cell (DSSC) based on metal oxide photo anode is of greater interest at the present scenario. The light harvesting capability of the photo anode is the most crucial factor in determining the efficiency of DSSC. Thus to decide on suitable photo anode to attain greater efficiency is critical confront. The wide band gap (3.6eV) and higher electron mobility (me ~ 250 cm2 V-1 S‑1) of SnO2 put together a promising material when compared to other photo electrode materials . Besides, its low sensitivity towards UV makes them more stable for a long time. This review will focus on recent progress in development of SnO2 and hybrid SnO2 based photo anode material and its allied key issues based on articles published in the last five years. A short introduction about the current energy scenario, DSSC principle and working will be presented followed by a brief description about the importance of photo anode in DSSC. Subsequently a complete review on SnO2 and hybrid SnO2 photo anode materials will be explained together with the recent year reports considering all the challenges and perspectives related to DSSC.

Functionalization of SnO₂ photoanode through Mg-doping and TiO₂-coating to synergically boost dye-sensitized solar cell performance

Mg-doped SnO₂ with an ultrathin TiO₂ coating layer was successfully synthesized through a facile nanoengineering art. Mg-doping and TiO₂-coating constructed functionally multi-interfaced SnO₂ photoanode for blocking charge recombination and enhancing charge transfer in dye-sensitized solar cells (DSC). The designed nanostructure might play a synergistic effect on the reducing recombination and prolonging the lifetime in DSC device. Consequently, a maximum power conversion efficiency of 4.15% was obtained for solar cells fabricated with the SnO₂-based photoelectrode, exhibiting beyond 5-fold improvement in comparison with pure SnO₂ nanomterials photoelectrode DSC (0.85%).