Advanced design of metal nanoclusters and single atoms embedded in C1N1-derived carbon materials for ORR, HER, and OER

5 figures.-- Supplementary information available.Single atoms and nanoclusters of Fe, Ni, Co, Cu, and Mn are systematically designed and embedded in a well-defined C1N1-type material that has internal cavities of ≈0.6 nm based on four N atoms. These N atoms serve as perfect anchoring points for the nucleation of small nanoclusters of different metal natures through the creation of metal-nitrogen (TM-N4) bonds. After pyrolysis at 800 °C, TM@CNx-type structures are obtained, where TM is the transition metal and x < 1. Fe@CNx and Co@CNx are the most promising for oxygen reduction reaction and hydrogen evolution reaction, respectively, with a Pt-like performance, and Ni@CNx is the most active for oxygen evolution reaction (OER) with an EOER of 1.59 V versus RHE, far outperforming the commercial IrO2 (EOER = 1.72 V). This systematic and benchmarking study can serve as a basis for the future design of advanced multi-functional electrocatalysts by modulating and combining the metallic nature of nanoclusters and single atoms.ANR-15-IDEX-04-LUE and the TALiSMAN and TALiSMAN2 projects, financed by the European Regional Development Fund (ERDF), are gratefully acknowledged. J.Q.B. thanks the Ministerio de Universidades, the European Union, and the University of Alicante for the financial support (MARSALAS21-21). S.G.D. thanks the Ministerio de Universidades, the European Union, and the University of Oviedo for the financial support (MU-21-UP2021-030 30267158).Peer reviewe

Supplementary material for Zinc doping enhances the electrocatalytic properties of cobalt borides for the hydrogen evolution reaction

Energy Dispersive X-ray Spectroscopy (EDS) was used to obtain information about the chemical nature of the Co-B and Co-Zn-B samples. As observed in Supplementary Figure S1A, the EDS profiles show the presence of cobalt, oxygen and boron in the Co-B sample. If the material is prepared with the addition of Zn(NO3)2, a new intense peak is observed in the EDS profile (Supplementary Figure S1B), which is attributed to the presence of Zn in the material composition Moreover, EDS mapping was performed to further check the distribution of Co and Zn atoms in HRTEM images.The particle size distributions of the two samples are shown in Supplementary Figure S2. To assess whether the HER performance damaged the chemical nature of the Co-Zn-B material, CV before and after the HER measurements were performed. Supplementary Figure S3 shows that the CV-profile does not exhibit any significant change in the electrochemical behavior of Co-Zn-B, suggesting strong stability under HER working conditions. Furthermore, to confirm the high stability of the Co-Zn-B sample, chronopotentiometric (CP) measurements were performed at a fixed current density of −5 mA cm−2 (Supplementary Figure S4).-- Creative Commons Attribution License (CC BY).Figure S1: EDS of (a) Co-B and (b) Co-Zn-B. Figure S2 : Particle size distribution of Co-B and Co-Zn-B. Figure S3 : CV pre and post HER of Co-Zn-B at a scan rate of 50 mV·s-1 in a N2-saturated 0.1 M KOH solution. Figure S4: Chronopotentiometric analysis of Co-Zn-B sample at a fixed current density of -5 mA·cm-2.JQ-B thanks the Ministerio de Universidades, the European Union and the University of Alicante for the financial support (MARSALAS21-21). SG-D thanks the Ministerio de Universidades, the European Union and the University of Oviedo for the financial support (MU-21-UP2021-030 30267158).This study was partly supported by the French PIA project “Lorraine Université d’Excellence,” reference ANR-15-IDEX-04-LUE and the TALiSMAN project funded by ERDF (2019-000214).Peer reviewe

The deception of an infinite view – exploring machine vision in digital art

This paper examines prediction product called Queryable Earth a project to “make Earth searchable for all”. A project pitched by the company Planet, owner of the largest fleet of Earth-imaging satellites in orbit and an archive of satellite images growing with terabytes of fresh data every day. The aim of Queryable Earth is to combine geospatial intelligence with machine learning. By training artificial neural networks to classify objects, identify geographic features, and monitor change over time, the implied intention is to create a predictive, omniscient oracle. In this paper Queryable Earth functions as an example of a ‘nonconscious cognitive assemblage’ combining aerial image with machine learning techniques such as artificial neural networks. To examine the predictive potential and the assumed objectivity of machine vision systems such as Queryable Earth I turn to histories of aerial photography and examples of contemporary digital art to illustrate how human and technical cognition entwine revealing how seemingly automated processes such as rendering of satellite images and pattern recognition still inherit human biases and are prone to emphasize them. Furthermore, I use digital artworks to illustrate how Queryable Earth as an “all seeing machine” is limited to a singular aerial perspective which cannot penetrate the surface and how predictions produced by such systems are constrained the quality and selection of data they are trained on

Invoking spirits in the material world: Spiritualism, surrealism, and spirituality at work

This paper considers the recent upsurge of interest in workplace spirituality through an analysis of three cultural movements – late nineteenth century spiritualism, early twentieth century surrealism, and late twentieth/early twenty-first century 'spirituality at work'. These movements share a common interest in harnessing the power of the human spirit in the transformation and 'betterment' of social life. It is argued that these movements have successively adopted and de-radicalised invocations of the spirit world such that the proto-feminism and utopianism of spiritualism and the revolutionary pretensions of surrealism have been usurped by a strongly managerialist discourse of workplace spirituality. The paper ends with a consideration of the implications of these developments for the critical study of spirituality, management and organisation