Enhanced Photostability and Photoactivity of Ruthenium Polypyridyl-Based Photocatalysts by Covalently Anchoring Onto Reduced Graphene Oxide.

Recentstudies toward finding more efficient ruthenium metalloligands for photocatalysis applications have shown that the derivatives of the linear [Ru(dqp)2]2+ (dqp: 2,6-di(quinolin-8-yl)-pyridine) complexes hold significant promise due to their extended emission lifetime in the µs time scale while retaining comparable redox potential, extinction coefficients, and absorption profile in the visible region to [Ru(bpy)3]2+ (bpy: 2,2'-bipyridine) and [Ru(tpy)2]2+ (tpy: 2,2':6',2″-terpyridine) complexes. Nevertheless, its photostability in aqueous solution needs to be improved for its widespread use in photocatalysis. Carbon-based supports have arisen as potential solutions for improving photostability and photocatalytic activity, yet their effect greatly depends on the interaction of the metal complex with the support. Herein, we present a strategy for obtaining Ru-polypyridyl complexes covalently linked to aminated reduced graphene oxide (rGO) to generate novel materials with long-term photostability and increased photoactivity. Specifically, the hybrid Ru(dqp)@rGO system has shown excellent photostable behavior during 24 h of continual irradiation, with an enhancement of 10 and 15% of photocatalytic dye degradation in comparison with [Ru(dqp)2]2+ and Ru(tpy)@rGO, respectively, as well as remarkable recyclability. The presented strategy corroborates the potential of [Ru(dqp)2]2+ as an interesting photoactive molecule to produce more advantageous light-active materials by covalent attachment onto carbon-based supports.

Progress in Development of Photocatalytic Processes for Synthesis of Fuels and Organic Compounds under Outdoor Solar Light.

With photovoltaics becoming a mature, commercially feasible technology, society is willing to allocate resources for developing and deploying new technologies based on using solar light. Analysis of projects supported by the European Commission in the past decade indicates exponential growth of funding to photocatalytic (PC) and photoelectrocatalytic (PEC) technologies that aim either at technology readiness levels (TRLs) TRL 1-3 or TRL > 3, with more than 75 Mio€ allocated from the year 2019 onward. This review provides a summary of PC and PEC processes for the synthesis of bulk commodities such as solvents and fuels, as well as chemicals for niche applications. An overview of photoreactors for photocatalysis on a larger scale is provided. The review rounds off with the summary of reactions performed at lab scale under natural outdoor solar light to illustrate conceptual opportunities offered by solar-driven chemistry beyond the reduction of CO2 and water splitting. The authors offer their vision of the impact of this area of research on society and the economy.

The first record of Tremoctopus violaceus sensu stricto Delle Chiaje,1830 in southwestern Gulf of Mexico gives a hint of the taxonomic status of Tremoctopus gracilis.

Knowledge on species taxonomic identity is essential to understand biological and biogeographical processes and for studies on biodiversity. Species the genus Tremoctopus have been confused in the past and are inconsistently identified. To clarify of the taxonomic diagnosis Tremoctopus violaceus Delle Chiaje, 1830, an evaluation of morphological and meristic characters, as well as morphometric indices and genetic analyses, was undertaken. The analyzed octopod was an opportunistically collected mature female of 640 mm in total length, with a mantle length of 135 mm and a total weight of 1.02 kg. Evidence of autotomy as a defensive mechanism for protecting the egg mass is presented. The 16S haplotype sequenced from this specimen represents the first one publicly available for this species from the Gulf of Mexico. The genetic divergence between this haplotype and those reported from the Pacific Ocean is representative of interspecific variation in other taxa, which suggests that "T. violaceus" in the Pacific Ocean (KY649286, MN435565, and AJ252767) should be addressed as T. gracilis instead. Genetic evidence to separate T. violaceus and T. gracilis is presented. The studied specimen from the Gulf of Mexico represents the westernmost known occurrence of T. violaceus and the first record from the southwestern Gulf of Mexico.

Octopus insularis as a new marine model for evolutionary developmental biology.

Octopuses are intriguing organisms that, together with squids and cuttlefishes, form the extant coleoid cephalopods. This group includes many species that can potentially be used as models in the fields of biomedicine, developmental biology, evolution, neuroscience and even for robotics research. The purpose of this work is to first present a simple method for maintaining Octopus insularis embryos under a laboratory setup. Second, we show that these embryos are suitable for detailed analyses of specific traits that appear during developmental stages, including the eyes, hearts, arms, suckers, chromatophores and Kölliker's organs. Similar complex traits between cephalopods and vertebrates such as the visual, cardiovascular, neural and pigmentation systems are generally considered to be a result of parallel evolution. We propose that O. insularis embryos could be used as a model for evolutionary developmental biology (or EvoDevo) research, where comparisons of the morphogenetic steps in the building of equivalent organs between cephalopods and known vertebrate model systems could shed light on evolutionary convergences and deep homologies.

Carboxylic acid-capped ruthenium nanoparticles: experimental and theoretical case study with ethanoic acid.

Given that the properties of metal nanoparticles (NPs) depend on several parameters (namely, morphology, size, surface composition, crystalline structure, etc.), a computational model that brings a better understanding of a structure-property relationship at the nanoscale is a significant plus in order to explain the surface properties of metal NPs and also their catalytic viability, in particular, when envisaging a new stabilizing agent. In this study we combined experimental and theoretical tools to obtain a mapping of the surface of ruthenium NPs stabilized by ethanoic acid as a new capping ligand. For this purpose, the organometallic approach was applied as the synthesis method. The morphology and crystalline structure of the obtained particles was characterized by state-of-the art techniques (TEM, HRTEM, WAXS) and their surface composition was determined by various techniques (solution and solid-state NMR, IR, chemical titration, DFT calculations). DFT calculations of the vibrational features of model NPs and of the chemical shifts of model clusters allowed us to secure the spectroscopic experimental assignations. Spectroscopic data as well as DFT mechanistic studies showed that ethanoic acid lies on the metal surface as ethanoate, together with hydrogen atoms. The optimal surface composition determined by DFT calculations appeared to be ca. [0.4-0.6] H/Rusurf and 0.4 ethanoate/RuSurf, which was corroborated by experimental results. Moreover, for such a composition, a hydrogen adsorption Gibbs free energy in the range -2.0 to -3.0 kcal mol-1 was calculated, which makes these ruthenium NPs a promising nanocatalyst for the hydrogen evolution reaction in the electrolysis of water.

An integrative taxonomic approach reveals Octopus insularis as the dominant species in the Veracruz Reef System (southwestern Gulf of Mexico).

The common octopus of the Veracruz Reef System (VRS, southwestern Gulf of Mexico) has historically been considered as Octopus vulgaris, and yet, to date, no study including both morphological and genetic data has tested that assumption. To assess this matter, 52 octopuses were sampled in different reefs within the VRS to determine the taxonomic identity of this commercially valuable species using an integrative taxonomic approach through both morphological and genetic analyses. Morphological and genetic data confirmed that the common octopus of the VRS is not O. vulgaris and determined that it is, in fact, the recently described O. insularis. Morphological measurements, counts, indices, and other characteristics such as specific colour patterns, closely matched what had been reported for O. insularis in Brazil. In addition, sequences from cytochrome oxidase I (COI) and 16S ribosomal RNA (r16S) mitochondrial genes confirmed that the common octopus from the VRS is in the same highly supported clade as O. insularis from Brazil. Genetic distances of both mitochondrial genes as well as of cytochrome oxidase subunit III (COIII) and novel nuclear rhodopsin sequences for the species, also confirmed this finding (0-0.8%). We discuss our findings in the light of the recent reports of octopus species misidentifications involving the members of the 'O. vulgaris species complex' and underscore the need for more morphological studies regarding this group to properly address the management of these commercially valuable and similar taxa.

Diversity and abundance of conspicuous macrocrustaceans on coral reefs differing in level of degradation.

Coral reefs sustain abundant and diverse macrocrustaceans that perform multiple ecological roles, but coral reefs are undergoing massive degradation that may be driving changes in the species composition and abundance of reef-associated macrocrustaceans. To provide insight into this issue, we used non-destructive visual census techniques to compare the diversity and abundance of conspicuous macrocrustaceans (i.e., those >1 cm and visible without disturbance) between two shallow Caribbean coral reefs similar in size (∼1.5 km in length) and close to each other, but one ("Limones") characterized by extensive stands of the branching coral Acropora palmata, and the other ("Bonanza") dominated by macroalgae and relic coral skeletons and rubble (i.e., degraded). We also assessed the structural complexity of each reef and the percent cover of various benthic community components. Given the type of growth of A. palmata, we expected to find a greater structural complexity, a higher cover of live coral, and a lower cover of macroalgae on Limones, and hence a more diverse and abundant macrocrustacean community on this reef compared with Bonanza. Overall, we identified 63 macrocrustacean species (61 Decapoda and two Stomatopoda). Contrary to our expectations, structural complexity did not differ significantly between the back-reef zones of these reefs but varied more broadly on Limones, and the diversity and abundance of macrocrustaceans were higher on Bonanza than on Limones despite live coral cover being higher on Limones and macroalgal cover higher on Bonanza. However, the use of various types of microhabitats by macrocrustaceans differed substantially between reefs. On both reefs, the dominant species were the clinging crab Mithraculus coryphe and the hermit crab Calcinus tibicen, but the former was more abundant on Bonanza and the latter on Limones. M. coryphe occupied a diverse array of microhabitats but mostly coral rubble and relic skeletons, whereas C. tibicen was often, but not always, found associated with colonies of Millepora spp. A small commensal crab of A. palmata, Domecia acanthophora, was far more abundant on Limones, emerging as the main discriminant species between reefs. Our results suggest that local diversity and abundance of reef-associated macrocrustaceans are partially modulated by habitat degradation, the diversity of microhabitat types, and the establishment of different commensal associations rather than by structural complexity alone.