New insights into the efficient charge transfer of ternary chalcogenides composites of TiO2

A two-step solvothermal synthesis was adopted to prepare AgXSe2-TiO2 (X = In, Bi) composites. DFT study of the pristine parent samples showed the formation of the hexagonal phase of AgBiSe2, and tetragonal phase of AgInSe2 and TiO2, which corroborated the experimentally synthesised structures. Both the AgBiSe2-TiO2 and AgInSe2-TiO2 composites displayed enhanced visible light absorption and reduced band gap in the UV-DRS patterns. The XPS results exhibited a shift in binding energy values and the TEM results showed the formation of spherical nanoparticles of both AgBiSe2 and AgInSe2. The PL signals displayed delayed recombination of the photogenerated excitons. The as synthesised materials were studied for their photocatalytic efficiency, by hydrogen generation, degradation of doxycycline, and antimicrobial disinfection (E. coli and S. aureus). The composite samples illustrated more than 95 % degradation results within 180 min and showed 5 log reductions of bacterial strains within 30 min of light irradiation. The hydrogen production outcomes were significantly improved as the AgBiSe2 and AgInSe2 based composites illustrated 180-fold and 250-fold enhanced output compared to their parent samples. The enhanced photocatalytic efficiency displayed is attributed to the delayed charge recombination of the photogenerated electron-hole pairs in the AgXSe2-TiO2 interface. Formation of a p-n nano heterojunction for AgBiSe2-TiO2 and type II heterojunction for AgInSe2-TiO2 composite are explained

Exploring attachment incoherence in bereaved families’ therapy narratives: An attachment theory-informed thematic analysis

Attachment theory predicts that family bereavement leads even securely attached individuals to experience temporary attachment insecurity. This paper explores how incoherence, a narrative marker of attachment insecurity, is displayed in the talk of families undergoing bereavement family therapy. This study uses the lens of attachment theory, and specifically the Adult Attachment Interview (AAI), to explore how members of five families talked about the loss of a close family member and how interactions between therapist and family members could hinder a coherent dialogue about the death. The families were recruited through Winston’s Wish, a UK-based family bereavement charity. The analysis centres on the “Telling the story” intervention, used at the start of therapy, in which family members together tell the story of the death. Families also re-told the story in an extra family session towards the end of the therapy for the purposes of this research. Transcripts of the therapy sessions were analysed using thematic analysis, with some codes developed directly from the unresolved loss codes of the AAI and other codes generated from analysing the transcripts through the lens of attachment theory. Through a micro focus on therapy process, the study provides tentative support for suppositions in attachment theory about the psychological importance of (fostering) coherent speech as well as information about potentially helpful versus unhelpful therapist actions in family bereavement therapy. The findings have relevance for bereavement therapy interventions, therapy training and research practice