Quantum Dot-Sensitized Solar Cells Based on Directly Adsorbed Zinc Copper Indium Sulfide Colloids

Heavy metal-based quantum dots (QDs) have demonstrated to behave as efficient sensitizers in QD-sensitized solar cells (QDSSCs), as attested by the countless works and encouraging efficiencies reported so far. However, their intrinsic toxicity has arisen as a major issue for the prospects of commercialization. Here, we examine the potential of environmentally friendly zinc copper indium sulfide (ZCIS) QDs for the fabrication of liquid-junction QDSSCs by means of photoelectrochemical measurements. A straightforward approach to directly adsorb ZCIS QDs on TiO2 from a colloidal dispersion is presented. Incident photon-to-current efficiency (IPCE) spectra of sensitized photoanodes show a marked dependence on the adsorption time, with longer times leading to poorer performances. Cyclic voltammograms point to a blockage of the channels of the mesoporous TiO2 film by the agglomeration of QDs as the main reason for the decrease in efficiency. Photoanodes were also submitted to the ZnS treatment. Its effects on electron recombination with the electrolyte are analyzed through electrochemical impedance spectroscopy and photopotential measurements. The corresponding results bring out the role of the ZnS coating as a barrier layer preventing electron leakage toward the electrolyte, as argued in other QD-sensitized systems. The beneficial effect of the ZnS coating is ultimately reflected on the power conversion efficiency of complete devices, reaching values of 2 %. In a more general vein, through these findings, we aim to call the attention to the potentiality of this quaternary alloy, virtually unexplored as a light harvester for sensitized devices.N.G. is grateful to the Spanish Ministry of Education for the award of an FPU grant. The group acknowledges support of the Spanish Ministry of Economy and Competitiveness through projects HOPE CSD2007-00007 (Consolider Ingenio 2010) and MAT2012-37676 (Fondos FEDER)

Post-funcionalización de polianilina con grupos precursores de la función vinilsulfona

Resumen de la comunicación presentada en la XXXI Reunión Bienal de la RSEQ, Toledo, 9-14 septiembre 2007En este trabajo se describe la obtención de polianilina modificada con grupos precursores de la función vinilsulfónica, bien conocida por su reactividad específica a fibras celulósicas (algodón, lino...) y proteicas (lana, seda...). Las cadenas modificadas se obtuvieron mediante un procedimiento de post-funcionalización mediante la reacción de acoplamiento con sales de diazonio, que ha demostrado ser una ruta útil y versátil de incorporación de grupos funcionales en polímeros conductores.Generalitat Valenciana (proyecto GV06-106) Ministerio de Educación y Ciencia (proyecto MAT2004-01479

Identifying Reactive Sites and Surface Traps in Chalcopyrite Photocathodes

Gathering information on the atomic nature of reactive sites and trap states is key to fine tuning catalysis and suppressing deleterious surface voltage losses in photoelectrochemical technologies. Here, spectroelectrochemical and computational methods were combined to investigate a model photocathode from the promising chalcopyrite family: CuIn0.3Ga0.7S2. We found that voltage losses are linked to traps induced by surface Ga and In vacancies, whereas operando Raman spectroscopy revealed that catalysis occurred at Ga, In, and S sites. This study allows establishing a bridge between the chalcopyrite's performance and its surface's chemistry, where avoiding formation of Ga and In vacancies is crucial for achieving high activity.This work was supported by the Swiss National Science Foundation (SNSF) under the Ambizione Energy grant (PZENP2_166871) and by the Gaznat-EPFL Research Program. M.B. and U.A. were supported by the Swiss National Science Foundation Professorship Grants PP00P2_157615 and PP00P2_187185. Calculations were performed on UBELIX, the HPC cluster at the University of Bern. M.X. is grateful for the support from the China Scholarship Council (No. CSC201806160172) and the Strategic Japanese–Swiss Science and Technology program (514259). Open access funding provided by Ecole Polytechnique Federale de Lausanne

Identifizierung von reaktiven Zentren und Oberflächenfallen in Chalkopyrit-Photokathoden

Das Sammeln von Informationen über die atomare Natur von reaktiven Zentren und Fallenzuständen ist der Schlüssel zur Feinabstimmung der Katalyse und zur Unterdrückung schädlicher Oberflächenpotentialverluste in photoelektrochemischen Technologien. Hier wurden spektroelektrochemische und rechnerische Methoden kombiniert, um eine Modellphotokathode aus der vielversprechenden Chalkopyrit-Familie zu untersuchen: CuIn0.3Ga0.7S2. Es wurde festgestellt, dass Potentialverluste mit Fallen verbunden sind, die durch Oberflächen-Ga- und In-Leerstellen induziert werden, wohingegen Operando-Raman-Spektroskopie zeigte, dass Katalyse an Ga-, In- und S-Stellen stattfand. Diese Studie ermöglicht es, eine Brücke zwischen der Leistung des Chalkopyrits und seiner Oberflächenchemie zu schlagen, wobei die Vermeidung der Bildung von Ga- und In-Leerstellen entscheidend ist, um eine hohe Aktivität zu erzielen.Diese Arbeit wurde vom Schweizerischen Nationalfonds (SNF) im Rahmen des Ambizione Energy Grant (PZENP2_166871) und vom Gaznat-EPFL Forschungsprogramm unterstützt. M.B. und U.A. wurden durch die Förderungsprofessuren PP00P2_157615 und PP00P2_187185 des Schweizerischen Nationalfonds unterstützt. Die Berechnungen wurden auf UBELIX, dem HPC-Cluster der Universität Bern, durchgeführt. M.X. dankt dem China Scholarship Council (Nr. CSC201806160172) und dem Strategic Japanese–Swiss Science and Technology-Programm (514259) für die Unterstützung. Open access funding provided by Ecole Polytechnique Federale de Lausanne

Sensibilización y formación en la accesibilidad e inclusión de las personas con discapacidad visual al proceso de Enseñanza-Aprendizaje. SENSIVISUAL-UCM

El objetivo general de este proyecto viene definido por la necesidad de inclusión de las personas con discapacidad visual, parcial o absoluta, en el mundo académico, así como la de favorecer su incorporación al mundo laboral con unas condiciones formalizadas y estables. A través de las acciones realizadas en este proyecto de innovación y mejora de la calidad docente se podrá mejorar la accesibilidad en los diferentes Grados de la Universidad Complutense de Madrid, ayudando en la generación de material didáctico y composición de grupos de trabajo que fomenten el trabajo colaborativo permitiendo el re-fuerzo académico

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

The pitfalls in electrocatalytic nitrogen reduction for ammonia synthesis

Ammonia synthesis by electrocatalytic nitrogen reduction reaction (EC-NRR) has gained momentum in recent years fueled by its potential to operate at ambient conditions, unlike the highly energy-intensive yet long-standing Haber-Bosch process. However, the large disparity of the yields and Faradic efficiencies reported for EC-NRR raises serious concerns about the reliability of the experimental results. In this perspective, we elaborate on the potential sources of error when assessing EC-NRR and update the testing protocols to circumvent them, and more importantly, we pose a general call for consensus on ammonia production analysis and reporting to lay the solid foundations that this burgeoning field requires to thrive.J.L. acknowledges the Chinese Thousand Talents Program for Young Professionals, the startup funding from Nankai University and the ‘‘111” project (Grant No. B16027)