1,720,970 research outputs found
Sub 10 nm CoO nanoparticle-decorated graphitic carbon nitride for solar hydrogen generation via efficient charge separation
No full textSolar hydrogen generation is one of the most compelling concepts in modern research to address both the energy and environmental issues simultaneously for the survival of the human race. A Type II heterojunction (CoO–GCN) was fabricated by decorating sub 10 nm CoO nanoparticles (NPs) on the graphitic carbon nitride (GCN) surface. It exhibited improved absorption of UV-VIS light and efficiently separate the photogenerated electrons and holes in opposite directions. A maximum hydrogen generation rate of 9.8 mmol g(−1) h(−1) was recorded using CoO–GCN from 10% aqueous triethanolamine under simulated sunlight in the presence of 1 wt% Pt. The rate is 3.8 times higher than that of bare GCN. Furthermore, it showed excellent stability for up to five repeated uses. Interestingly, the study also revealed that untreated seawater could replace the deionized water. The cooperative participation of the uniform shape and size of CoO NPs firmly grafted on GCN resulted in remarkable performance for solar hydrogen generation
Fabrication of defective mesoporous cerium oxide nanostructure for promoting an efficient and stable electrocatalytic oxygen evolution reaction
No full textThe development of renewable energy technologies, such as fuel cells, electrolysersand metal-air batteries, relies heavily on the availability of highly efficient electrocatalysts for the anodic oxygen evolution reaction (OER). Defected ceria (D-CeO2) has a high potential to compete with the activity of RuO2 based OER catalysts. We have synthesiseda mesoporous nanostructure ceria (CeO2) with induced defects using a simple and economical approach at a relatively low temperature. The observed catalytic activity of the prepared D-CeO2 porous nanostructure was found to be remarkable. Additionally, the nanostructure exhibited a high tolerance to methanol and demonstrated durability towards OER in alkaline media. During the experiment, it was observed that the catalyst exhibited noteworthy activity in the OER compared to the commercially available RuO2 catalyst, as this is evident by a higher current density and more negative onset potential. The catalyst's remarkable OER activity is attributed to the synergistic effect resulting from the combination of defect sites and the porous structure of CeO2. CeO2 mesoporous nanostructures serve as excellent electrocatalysts for OER due to their elevated surface area, robust catalytic activity, and stability. Furthermore, their mesoporous configuration enhances mass transport, expedites oxygen transfer, mitigates electrode polarisation, and enhances the overall electrochemical performance
Assessing the non-wettability and sustainability of cellulosic jute for roadway applications
No full textDuring the last decade, the usage of geotextiles has tremendously grown into a needful auxiliary, particularly regarding soil protection. Although geotextiles made of natural fibers blended with synthetic materials are considered a modern achievement, backing up the basic concept of increasing the stability of roads and soils, they suffer from severe degradation. It includes the environmental exposure such as hydrolysis, and thermal, chemical, and biological degradation, affecting their long-term performance. This paper focuses on the jute-based geotextile having outstanding water repellency with a water contact angle of 169° and immutable tensile strength (~ 12 MPa) when incorporated with hexadecyltrimethoxysilane (HDTMS) modified titanium dioxide (TiO2) nanoparticles (nps) via drop casting technique. Herein, the durability of the coating was examined by sand (dropping sand particles) and impact (driving two-wheeler) tests on the coated jute sample. In addition, the coated samples were immersed in different aqueous mediums, and the behaviour in the tensile strength was noted. Similarly, the thermal degradation affecting the tensile strength was also evaluated. Lastly, biodegradability was judged by burying the samples for different periods in the soil. These outcomes demonstrate the potential of the HDTMS-TiO2 nps coating on jute geotextile having a suitable mechanically durable and sustainable superhydrophobic property that could be successfully used in roadway applications
Review of the progress of solar-driven interfacial water evaporation (SIWE) toward a practical approach
No full textSolar-driven interfacial water evaporation (SIWE), which has shown a promising use in the fields of water evaporation, desalination, wastewater treatment, and other related activities, has emerged as a practical and effective method for capturing solar energy. SIWE device development and upgraded structural design with increased performance have received much attention in the last decade. In this review article, we revise the level of development achieved for different solar absorber materials and substrates, and their conceptual design in terms of light absorptivity, heat and water management, and structural engineering, along with various potential SIWE applications, including desalination, sterilization, wastewater evaporation, energy generation, and others. Finally, the progress regarding the recent advancements in scalable solar-driven clean water generation is presented. This review summarizes the inclusive development in SIWE from laboratory to practical applications, inspiring new thinking with solutions to the practical challenges and serving as an outline for future investigations
Environmental and economic benefits of single-atom catalysts in energy conversion and storage
No full textSingle-atom catalysts (SACs) have gained significant popularity in heterogeneous catalysis owing to their high activity and stability. The predominant focus of current research is centred around the dispersion of SACs onto a support medium, aiming to enhance the efficiency of energy conversion and storage systems. The utilization of these catalysts has been associated with environmental and economic benefits. This perspective article provides an overview of the latest advancements in SACs used for energy conversion and storage applications, with an emphasis on their potential environmental and economic benefits. It also provides insights into the future applications of SACs in energy conversion and storage. In addition, the article investigates emerging opportunities for energy conversion and storage systems. Furthermore, the article provides a comprehensive analysis of the key benefits, challenges, and potential factors that may influence the advancement of energy conversion and storage technologies
Facile Synthesis of Crystalline Molybdenum Carbide (Mo2C) Nanoparticles Coupled with a N-Doped Porous Carbon Sheet: A Synergistic Effect on the Electrocatalytic Hydrogen Evolution Reaction
No full textMo2C is a unique material due to its tunable phase and electronic structures. Because of the interaction of molybdenum and carbon, the D band of molybdenum atoms expands, similar to Pt. This hybridization minimizes the energy required for hydrogen adsorption, thereby enhancing the electrocatalytic characteristics. In this article, we report the direct one-pot synthesis of Mo2C on N doped on a porous carbon sheet for electrocatalytic hydrogen evolution reactions using ammonium molybdate as a molybdenum source, glucose as a carbon source, and ammonia as a nitrogen source. The porosity and Mo2C nanostructure embedded in N-doped carbon have helped to facilitate the infusion of electrolytes and the detachment of hydrogen molecules from the surface of a Mo2C-N-doped porous carbon sheet. Besides, the prepared composite has shown the most efficient HER performances with the overpotential and Tafel slope of Mo2C and Mo2C-NC mA/cm2 being 133 and 95 mV and 76 and 69 mV dec–1, respectively; it also has excellent stability in an acidic medium. Because of its easy resource, simple preparation, and excellent performance, the prepared Mo2C on a N-doped carbon sheet has a significant potential to be an alternative for cost-effective hydrogen production
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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