Nanostructured hybrid polymer-inorganic solar cell active layers formed by controllable in situ growth of semiconducting sulfide networks.

Nanostructured composites of inorganic and organic materials are attracting extensive interest for electronic and optoelectronic device applications. In this paper, we introduce a general method for the fabrication of metal sulfide nanoparticle/polymer films employing a low-cost and low temperature route compatible with large-scale device manufacturing. Our approach is based upon the controlled in situ thermal decomposition of a solution processable metal xanthate precursor complex in a semiconducting polymer film.

Transient optical studies of interfacial charge transfer at nanostructured metal oxide/PbS quantum dot/organic hole conductor heterojunctions.

We report a transient absorption and luminescence study addressing the charge separation, recombination, and regeneration reactions at nanostructured metal oxide/PbS quantum dot/organic hole conductor heterojunctions. We show that yields of charge separation are significantly higher at PbS/SnO(2) interfaces relative to PbS/TiO(2) interfaces, and conclude that this behavior is a result of the ca. 300-500 meV lower conduction band edge in SnO(2) as compared to TiO(2).

Derivatised carbon powder electrodes: reagentless pH sensors.

In this report, we derivatise carbon powder with anthracene, azobenzene, diphenylamine, 9,10-diphenylanthracene, methylene blue, 3-nitrofluoranthene, 6-nitrochrysene, 9-nitroanthracene, 9,10-phenanthraquinone (PAQ), thionin, and fast black K (2,5-dimethoxy-4-[(4-nitrophenyl)azo]benzenediazonium chloride) and separately immobilise the resulting material onto a bppg electrode. We use cyclic voltammetry (CV) to demonstrate that the observed voltammetric response for each derivatised carbon is consistent with that of an immobilised species. Further, we use CV and square wave voltammetry (SWV) to investigate the effect of pH on the peak potentials of each compound studied over the range pH 1-12 and at elevated temperatures up to 70 degrees C in order to demonstrate the versatility of derivatised carbon electrodes as reagentless pH sensors.

4-Nitrobenzylamine partially intercalated into graphite powder and multiwalled carbon nanotubes: characterization using X-ray photoelectron spectroscopy and in situ atomic force microscopy.

We report the characterization of partial intercalation of 4-nitrobenzylamine (4-NBA) into edge-plane or edge-plane-like defect sites on the surface of both graphite powder and "bamboo-like" multiwalled carbon nanotubes (MWCNTs) using X-ray photoelectron spectroscopy (XPS). By comparing the XPS spectra of 4-NBA derivatized graphite powder and MWCNTs with that of graphite powder treated with benzylamine in a similar fashion, we conclude that benzylamine itself does not undergo partial intercalation. Using in situ atomic force microscopy, we are able to observe the partial intercalation of 4-NBA into an edge-plane-like "step" defect on the surface of a highly ordered pyrolytic graphite crystal in real time.

Cysteine methyl ester modified glassy carbon spheres for removal of toxic heavy metals from aqueous media.

Glassy carbon spherical powder (10-20 microm diameter) modified with cysteine methyl ester is found to be an inexpensive, novel material for the rapid removal of large quantities of toxic heavy metal ions such as Cd(II), Cu(II) and As(III) from aqueous media, with wide ranging potential applications such as third world drinking water filtration or environmental cleanup.

Abrasively immobilised multiwalled carbon nanotube agglomerates: a novel electrode material approach for the analytical sensing of pH.

We demonstrate for the first time that agglomerates of multiwalled carbon nanotubes (MWCNTs) can be formed in which the binder in the agglomerate is itself a redox-active molecular solid. Two separate agglomerates were formed by dissolving 9,10-phenanthraquinone (PAQ) or 1,2-napthaquinone (NQ) in acetone together with MWCNTs and adding an excess of aqueous solution to cause precipitation of agglomerates, approximately 10 microns in dimension, which consist of bundles of nanotubes running into and throughout the amorphous molecular solid that binds the agglomerate together. The nature of this structure, when immobilised on a substrate electrode and in contact with aqueous electrolyte solutions, gives rise to many three-phase boundaries, electrolyte|agglomerate|conductor, which is advantageous to the solid-state analytical electrochemistry of such a material as it imparts a larger electroactive surface area than other modified carbon electrodes.