A novel route to Pt-Bi2O3 composite thin films and their application in photo-reduction of water

A novel homoleptic bismuth(III) β-diketonate (dibenzoylmethane – dbm) complex [Bi(dbm)3]2 has been used as a precursor to thin films of crystalline β-Bi2O3, and hexachloroplatinic acid (H2PtCl6·6H2O) has been demonstrated as a suitable precursor for deposition of platinum nanoparticles, both deposited via aerosol-assisted chemical vapour deposition (AACVD). Thin films of Pt–Bi2O3 were co-deposited from a mixture of [Bi(dbm)3]2 and H2PtCl6·6H2O; the introduction of Pt particles into β-Bi2O3 causes hydrogen to be evolved during photolysis of water over the composite material, a property not found for Pt particles or β-Bi2O3 alone

Influencing FTO thin film growth with thin seeding layers: a route to microstructural modification

We report on the seeded growth of fluorine doped tin oxide (FTO) polycrystalline transparent conducting oxide (TCO) thin films on float glass using a novel two-step chemical vapour deposition (CVD) method. Aerosol-assisted CVD (AACVD) was used to grow a seed layer to direct and promote full film growth via an atmospheric pressure CVD (APCVD) overlay. The method allowed for reproducible control over morphology and denser, rougher, higher-performing TCO at a relatively low growth temperature (500 °C). Growth promotion depended on seeding time with an optimal seeding time being present, below which morphology control and conformal coverage was unavailable. The film properties and functional characteristics were characterised by SEM, AFM, XRD, XPS, UV-Vis-Near IR transmittance-reflectance and Hall Effect probe measurements. Highly transparent and electrically conductive films, comparable to commercial materials and with high roughness and low transmission haze values indicate the process yields high quality films with a controllable morphology that can be tuned to desired application. The versatile method provides a route towards the morphological control of high-quality FTO thin films with high optical clarity and low-emissivity properties and can be readily extended to a variety of different substrates and metal oxide materials

Al-, Ga-, and In-doped ZnO thin films via aerosol assisted CVD for use as transparent conducting oxides

Al-, Ga-, and In-doped ZnO thin films were deposited on glass substrates by aerosol assisted chemical vapour deposition (AACVD) at a deposition temperature of 450 °C. The air-stable compound zinc acetylacetonate [Zn(acac)2] was used as a Zn source, whilst for the dopants of Al, Ga and In, the corresponding trichloride was used. Methanol solutions of the metal salts were used as precursor solutions and N2 carrier gas was used for the aerosol. Films were grown in approximately 30 min and were synthesised using dopant values of 5, 10, 15 and 20 mol.% (with respect to the Zn) in the precursor solution. XRD analysis showed that the films were wurtzite ZnO. XPS analysis confirmed the presence of the dopants in the films. Several of the films showed high transparency (>80%) in the visible range, and low resistivity (∼10−3 Ω cm)

Watch out for the Aunties! Young British Asians' accounts of identity and substance use

This paper considers how young people able to trace their origins from Pakistan or India (henceforth 'Asians'), discuss their use of, or abstention from, alcohol and tobacco in terms of religious and cultural tradition. The role of religion, ethnicity, gender and generation in the uptake or avoidance of alcohol and tobacco was explored in 19 qualitative group and individual interviews with 47 Asians aged 16–26 years and analysed in terms of pioneering and conservative forms of tradition. Religious proscriptions on alcohol and tobacco were reported to be formally gender blind, but concerns about reputation and future marriage chances, sanctioned by gossip, meant that women's behaviour was consistently more constrained than men's. Muslims' abstinence from alcohol was tightly linked with an Islamic identity in that drinking jeopardised one's claim to being a Muslim, whereas cigarette smoking was tolerated among young men. Sikhs' and Hindus' avoidance of tobacco was strongly sanctioned, but smoking did not strongly jeopardise a religious identity. Sikh men's abstention indicated manly strength central to a devout identity. Some experimentation was possible out of view of the older generation, especially the aunties, but the risk of gossip damaging young women's reputations was keenly felt. While damage to women's reputations was hard to undo, men's reputations tarnished by substance use, could be compensated for by their parents' honourable status. Discussion of tradition as innovation was rare and met with resistance. Tradition was largely experienced as a constraint to be circumvented

Bismuth oxyhalides: synthesis, structure and photoelectrochemical activity

We report the synthesis and photoelectrochemical assessment of phase pure tetragonal matlockite structured BiOX (where X = Cl, Br, I) films. The materials were deposited using aerosol-assisted chemical vapour deposition. The measured optical bandgaps of the oxyhalides, supported by density functional theory calculations, showed a red shift with the increasing size of halide following the binding energy of the anion p-orbitals that form the valence band. Stability and photoelectrochemical studies carried out without a sacrificial electron donor showed the n-type BiOBr film to have the highest photocurrent reported for BiOBr in the literature to date (0.3 mA cm−2 at 1.23 V vs. RHE), indicating it is an excellent candidate for solar fuel production with a very low onset potential of 0.2 V vs. RHE. The high performance was attributed to the preferred growth of the film in the [011] direction, as shown by X-ray diffraction, leading to internal electric fields that minimize charge carrier recombination

Single Step Solution Processed GaAs Thin Films from GaMe 3 and BuAsH 2 under Ambient Pressure

This article reports on the possibility of low-cost GaAs formed under ambient pressure via a single step solution processed route from only readily available precursors, tBuAsH2 and GaMe3. The thin films of GaAs on glass substrates were found to have good crystallinity with crystallites as large as 150 nm and low contamination with experimental results matching well with theoretical density of states calculations. These results open up a route to efficient and cost-effective scale up of GaAs thin films with high material properties for widespread industrial use. Confirmation of film quality was determined using XRD, Raman, EDX mapping, SEM, HRTEM, XPS, and SIMS

Ogbu and the debate on educational achievement: an exploration of the links between education, migration, identity and belonging

This paper looks at some of the issues raised by Ogbu’s work in relation to the education of different minority ethnic groups. Ogbu poses questions such as the value attached to education, its links to the future and its measurable outcomes in terms of ‘success’ as experienced by black participants. The desire for better life chances leads families to consider migration to a new country or resettlement within the same country, thus making migration both a local and a global phenomenon. As an example, attention is drawn to the situation facing South Asian children and their families in the UK. In terms of ethnicity and belonging, the wider question that is significant for many countries in the West after ‘Nine-Eleven’ is the education of Muslim children. A consideration of this current situation throws Ogbu’s identification of ‘autonomous minority’ into question. It is argued that a greater understanding of diverse needs has to be accompanied by a concerted effort to confront racism and intolerance in schools and in society, thus enabling all communities to make a useful contribution and to avoid the ‘risk’ of failure and disenchantment

Laser-generated ultrasound with optical fibres using functionalised carbon nanotube composite coatings

Optical ultrasound transducers were created by coating optical fibres with a composite of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS). Dissolution of CNTs in PDMS to create the composite was facilitated by functionalisation with oleylamine. Composite surfaces were applied to optical fibres using dip coating. Under pulsed laser excitation, ultrasound pressures of 3.6 MPa and 4.5 MPa at the coated end faces were achieved with optical fibre core diameters of 105 and 200 μm, respectively. The results indicate that CNT-PDMS composite coatings on optical fibres could be viable alternatives to electrical ultrasound transducers in miniature ultrasound imaging probes