Charge Migration in CdS/NiS Schottky junction composites for benzylalcohol oxidation coupled with hydrogen production

Effective charge separation and migration pose a critical challenge in the field of solar-driven hydrogen production. In this work, a Z-scheme structured CuInS2/ZnIn2S4 heterojunction was successfully fabricated through a two-step hydrothermal synthesis method to significantly enhance the efficiency of solar-to-hydrogen energy conversion. Structural characterization revealed that the lattice-matched CuInS2/ZnIn2S4 heterojunction exhibits an enlarged interfacial contact area, which facilitates the transfer and separation of photogenerated charges. Microscopic analysis indicated that the CuInS2/ZnIn2S4 composite material has a tightly interwoven interface and a morphology resembling small sugar cubes. Photoelectrochemical spectroscopy analysis demonstrated that the heterojunction structure effectively enhances visible light absorption and charge separation efficiency, leading to an improvement in photocatalytic activity. Hydrogen production experimental data indicated that the CuInS2/ZnIn2S4 heterojunction photocatalyst prepared with a CuInS2 content of 20 wt% exhibits the highest hydrogen evolution rate, reaching 284.9 μmol·g-1·h-1. Moreover, this photocatalyst maintains robust photocatalytic stability even after three consecutive usage cycles. This study demonstrated that the Z-scheme CuInS2/ZnIn2S4 heterojunction photocatalyst exhibits enhanced hydrogen evolution efficiency, offering an effective structural design for harnessing solar energy to obtain hydrogen fuel. Therefore, this heterojunction photocatalyst is a promising candidate for practical applications in solar hydrogen production.

Stepwise oxygen vacancy‑titanium ensemble engineering and phosphorus-doping strategy to boost rhodium nanoparticle-catalyzed hydrogen production.

The 2019 5th International Conference on Energy, Environment and Materials Science (ICEEMS 2019) has been held on June 21-23,2019 in Singapore. ICEEMS 2019 is to bring together innovative academics and industrial experts in the field of energy, environment and materials science to a common forum. The primary goal of the conference is to promote research and developmental activities in energy, environment and materials science and another goal is to promote scientific information interchange between researchers, developers, engineers, students, and practitioners working all around the world. This year, ICEEMS 2019 was co-sponsored by Singapore Polytechnic and Nanjing University of Science and Technology.Assoc. Prof. Dr. Nur Islami (Physics PMIPA Department Universitas Riau, Indonesia), Prof. Cao Guan (Northwestern Polytechnical University) and Assoc. Prof. Zhenbo Xu (South China University of Technology, China) have been invited as the keynote speakers. The primary goal of the conference is to promote research and developmental activities in energy, environment and materials science and another goal is to promote scientific information interchange between researchers, developers, engineers, students, and practitioners working all around the world In this edition, ICEEMS 2019 is providing a venue of high quality state-of-the-art research papers in the following areas of interest:1. Energy Science, Environmental Pollution and Pollution Control2. Biomaterials, Composite Materials and Materials Processing Technology3. Power Electronics Applications and Smart Grid TechnologiesCommittee member, Conference Chairs, Technical Committee are avilable in the pdf.

Comparative study of interfacial charge transfer at the junction between CuInS2:In2S3/g-C3N4 photocatalysts for sacrificial hydrogen evolution activity

The hydrogen economy is accelerating technological evolutions toward highly efficient hydrogen production. In this work, the catalytic performance of NiO/NaCl for hydrogen production via autothermal reforming of ethyl acetate and water is further improved through lanthanum modification, and the resulted 3%-NiLaOy /NaCl catalyst achieves as high as 93% H2 selectivity and long-term stability at 600 °C. The promoting effect is caused by the strong interactions between lanthanum and NiO/NaCl, by which LaNiO3 and a novel LaOCl phase are formed. The key role of LaOCl in promoting low-temperature hydrogen production is highlighted, while effects of LaNiO3 are well known. The LaOCl (010) facet possesses high adsorption capacity toward co-chemisorbing ethyl acetate and water. LaOCl strongly interacts with ethyl acetate and H2 O in the form of hydrogen bonding and coordination effect. The interactions induce tensions inside ethyl acetate and H2 O, activate the molecules, and hence decrease the energy barrier for reaction. In situ Fourier transform infrared spectroscopy (FTIR) reveals that LaOCl along with NaCl enhances the adsorption ability of NiO/NaCl. Moreover, LaOCl improves the dispersion of Ni species in NiO-LaNiO3 -LaOCl nanosheets, which possess abundant active sites. The effects together promote hydrogen evolution. Furthermore, the NiLaOy /NaCl catalyst can be easily reborn after deactivation due to the water solubility of NaCl.

Photocatalytic pure/sea water splitting driven by solar light, emerges as the most promising strategy to address both the global energy crisis and environmental degradation. Research efforts have mainly resulted in the development of artificial photocatalytic solar hydrogen generation systems applicable to both freshwater and sea water. During long‐term testing, sea water demonstrated enhanced stability compared to pure water, offering experimental advantages in designing novel techniques aimed at reducing hydrogen generation costs, alleviating freshwater scarcity, and optimizing the utilization of natural water resources. Moreover, sea water splitting proves to be more effective in producing solar hydrogen due to the potential sacrificial action of salt ions, which promote hydrogen evolution within the photocatalytic system. This review comprehensively outlines the fundamental principles of photocatalytic H 2 production, examines the efficiencies and recent progress in hydrogen generation, explores the challenges faced, and envisions the future prospects of enhancing hydrogen production efficiency and reactivity through photocatalytic pure/sea water splitting.

A preliminary analysis of failed prestressing strands within a post-tensioned tendon on the Wando River bridge in South Carolina showed signs of possible hydrogen embrittlement. One proposed source of hydrogen is through galvanic coupling that may exist between the galvanized steel duct and the steel strands. This coupling, if present, can promote hydrogen evolution at the steel strand’s surface which may or may not be mitigated by the condition and quality of the grout. To fully understand the susceptibility of post-tensioned steel strands to hydrogen embrittlement in galvanized steel tendon ducts, the conditions that promote hydrogen production, the kinetics of hydrogen evolution and adsorption into the steel, as well as the subsequent loss of strength need to be well understood. In an effort to avoid these costly failures in the future, the likely effects of grout quality and the presence of grout deficiencies within galvanized steel ducts will be deduced from prior knowledge of hydrogen embrittlement mechanisms of cold-drawn steels. The focus of the review will be placed on studies and reports that have detailed the kinetics of hydrogen production and adsorption on cold drawn steel strands, and the relationship between stress state and hydrogen content distribution on strength reduction.

Electrocatalytic reduction of CO2 (CO2RR) is an attractive method of converting CO2 to solar fuels. Much research in this field has been focused on developing novel catalysts to enhance the activity and product distribution (selectivity). Copper has been studied widely as it can produce both one carbon (C1) products such as methane and formate, and products with two or more carbons (C2+) such as ethylene, ethanol, and n-propanol1. Copper is not immune from the competing hydrogen evolution reaction: the poor solubility of CO2 in water (~34 mM at ambient conditions) limits the CO2RR current density, and hydrogen generation is favored if the aqueous CO2 concentration becomes locally undersaturated close to the catalyst during CO2RR2. This limitation is even more pronounced for nanotextured copper, because the increased active surface area leads to faster depletion of local CO2 thereby promoting hydrogen evolution over CO2RR. Hence, overcoming these CO2 availability limitations can enable higher CO2RR activity while reducing co-evolution of hydrogen.In this work, we develop a gasphilic CO2 trap that increases gas-liquid mass transfer and maintains supersaturated CO2 concentration around the catalyst during CO2RR. Gasphilic surfaces need a special combination of surface chemistry and texture to capture bubbles and form a sheet of gas underwater which is called a plastron3. By creating pyramidal textures, CO2 bubbles are efficiently captured within the textures and form a CO2 plastron. When this plastron is placed proximal to both smooth and nanostructured copper catalysts during CO2RR, the current density is enhanced and maintained throughout the reaction, when compared to two commonly used methods of CO2 delivery: headspace and bubbling in the bulk electrolyte. The plastron allows for quick replenishment of CO2 during the CO2RR reaction in the vicinity of the catalyst. As a result, the H2 Faradaic efficiency is reduced from 33% to 13% on smooth copper, and from 62% to 33% on nanostructured copper. This is accompanied by an increased production of C2+ products including ethylene, ethanol and propanol, as well as acetone and acetate at Faradaic efficiencies exceeding 1%. We highlight the importance of this catalyst-proximal plastron approach by comparing against recent aqueous-phase CO2RR studies, and discuss how this approach can inform optimal design of continuous CO2RR systems such as gas-diffusion electrodes.[1] Nitopi, S., Bertheussen, E., Scott, S. B., Liu, X., Engstfeld, A. K., Horch, S., Seger, B., Stephens, I. E. L., Chan, K., Hahn, C., Nørskov, J. K., Jaramillo, T. F. & Chorkendorff, I. Progress and Perspectives of Electrochemical CO2 Reduction on Copper in Aqueous Electrolyte. Chem. Rev. 119, 7610–7672 (2019).[2] Lobaccaro, P., R. Singh, M., Lee Clark, E., Kwon, Y., T. Bell, A. & W. Ager, J. Effects of temperature and gas–liquid mass transfer on the operation of small electrochemical cells for the quantitative evaluation of CO2 reduction electrocatalysts. Physical Chemistry Chemical Physics 18, 26777–26785 (2016).[3] Panchanathan, D., Rajappan, A., Varanasi, K. K. & McKinley, G. H. Plastron Regeneration on Submerged Superhydrophobic Surfaces Using In Situ Gas Generation by Chemical Reaction. ACS Appl. Mater. Interfaces 10, 33684–33692 (2018).

This study focuses on enhancing the efficiency and stability of catalysts containing molybdenum (Mo) and tungsten (W) in the process of photocatalytic hydrogen production. Their structural, electronic, optical, and catalytic properties were thoroughly investigated. The development of low-cost and active catalysts for green hydrogen production is one of the key challenges in modern energy and environmental science. In this work, MoS₂- and WOx-based catalysts were synthesized via a hydrothermal method and subjected to thermal treatment at various temperatures. Their structural, morphological, and optical characteristics were comprehensively analyzed using advanced techniques such as Raman spectroscopy and UV-Vis. Hydrogen production reactions were carried out using a specially designed solar simulator, and the photocatalytic activity and stability of the catalysts were evaluated. The MoS-A320 sample demonstrated the highest hydrogen evolution activity (83 mL/h·g) and maintained 93% of its initial performance after five cycles, which is comparable to that of platinum-based catalysts. In contrast, WOx-based catalysts showed relatively lower activity. The results revealed that synthesis parameters and thermal treatment conditions have a significant influence on the properties of Mo- and W-based catalysts. This study represents an important step toward the development of efficient, stable, and affordable catalysts for green energy systems and water electrolysis. The findings offer new opportunities for designing cost-effective and high-performance Mo- and W-based catalysts.

We, scientists from a variety of disciplines, declare the following: Parties to the Stockholm Convention have taken action on three brominated flame retardants that have been listed in the treaty for global elimination. These substances include components of commercial penta-bromodiphenyl ether and commercial octa-bromodiphenyl ether, along with hexabromobiphenyl. Another brominated flame retardant, hexabromocyclododecane, is under evaluation. Many commonly used brominated and chlorinated flame retardants can undergo long-range environmental transport. Many brominated and chlorinated flame retardants appear to be persistent and bioaccumulative, resulting in food chain contamination, including human milk. Many brominated and chlorinated flame retardants lack adequate toxicity information, but the available data raises concerns. Many different types of brominated and chlorinated flame retardants have been incorporated into products even though comprehensive toxicological information is lacking. Brominated and chlorinated flame retardants present in a variety of products are released to the indoor and outdoor environments. Near-end-of-life and end-of-life electrical and electronic products are a growing concern as a result of dumping in developing countries, which results in the illegal transboundary movement of their hazardous constituents. These include brominated and chlorinated flame retardants. There is a lack of capacity to handle electronic waste in an environ-mentally sound manner in almost all developing countries and countries with economies in transition, leading to the release of hazardous substances that cause harm to human health and the environment. These substances include brominated and chlorinated flame retardants. Brominated and chlorinated flame retardants can increase fire toxicity, but their overall benefit in improving fire safety has not been proven. When brominated and chlorinated flame retardants burn, highly toxic dioxins and furans are formed. Therefore, these data support the following: Brominated and chlorinated flame retardants as classes of substances are a concern for persistence, bioaccumulation, long-range transport, and toxicity. There is a need to improve the availability of and access to information on brominated and chlorinated flame retardants and other chemicals in products in the supply chain and throughout each product’s life cycle. Consumers can play a role in the adoption of alternatives to harmful flame retardants if they are made aware of the presence of the substances, for example, through product labeling. The process of identifying alternatives to flame retardants should include not only alternative chemicals but also innovative changes in the design of products, industrial processes, and other practices that do not require the use of any flame retardant. Efforts should be made to ensure that current and alternative chemical flame retardants do not have hazardous properties, such as mutagenicity and carcinogenicity, or adverse effects on the reproductive, developmental, endocrine, immune, or nervous systems. When seeking exemptions for certain applications of flame retardants, the party requesting the exemption should supply some information indicating why the exemption is technically or scien-tifically necessary and why potential alternatives are not technically or scientifically viable; a description of potential alternative processes, products, materials, or systems that eliminate the need for the chemical; and a list of sources researched. Wastes containing flame retardants with persistent organic pollutant (POP) characteristics, including products and articles, should be disposed of in such a way that the POP content is destroyed or irreversibly transformed so that they do not exhibit the charac-teristics of POPs. Flame retardants with POP characteristics should not be permitted to be subjected to disposal operations that may lead to recovery, recycling, reclamation, direct reuse, or alternative uses of the substances. Wastes containing flame retardants with POP properties should not be transported across international boundaries unless it is for disposal in such a way that the POP content is destroyed or irreversibly transformed. It is important to consider product stewardship and extended producer responsibility aspects in the life-cycle management of products containing flame retardants with POP properties, including electronic and electrical products.

Electronics, such as printed circuit board (PCB), transistor, radio frequency identification (RFID), organic light emitting diode (OLED), solar cells, electronic display, lab on a chip (LOC), sensor, actuator, and transducer etc. are playing increasingly important roles in people’s daily life. Conventional fabrication strategy towards integrated circuit (IC), requesting at least six working steps, generally consumes too much energy, material and water, and is not environmentally friendly. During the etching process, a large amount of raw materials have to be abandoned. Besides, lithography and microfabrication are typically carried out in “Cleanroom” which restricts the location of IC fabrication and leads to high production costs. As an alternative, the newly emerging ink-jet printing electronics are gradually shaping modern electronic industry and its related areas, owing to the invention of a series of conductive inks composed of polymer matrix, conductive fillers, solvents and additives. Nevertheless, the currently available methods also encounter some technical troubles due to the low electroconductivity, complex sythesis and sintering process of the inks. As an alternative, a fundamentally different strategy was recently proposed by the authors’ lab towards truly direct writing of electronics through introduction of a new class of conductive inks made of low melting point liquid metal or its alloy. The method has been named as direct writing of electronics based on alloy and metal (DREAM) ink. A series of functional circuits, sensors, electronic elements and devices can thus be easily written on various either soft or rigid substrates in a moment. With more and more technical progresses and fundamental discoveries being kept made along this category, it was found that a new area enabled by the DREAM ink electronics is emerging, which would have tremendous impacts on future energy and environmental sciences. In order to promote the research and development along this direction, the present paper is dedicated to draft a comprehensive picture on the DREAM ink technology by summarizing its most basic features and principles. Some important low melting point metal ink candidates, especially the room temperature liquid metals such as gallium and its alloy, were collected, listed and analyzed. The merits and demerits between conventional printed electronics and the new direct writing methods were comparatively evaluated. Important scientific issues and technical strategies to modify the DREAM ink were suggested and potential application areas were proposed. Further, digestions on the impacts of the new technology among energy, health, and environmental sciences were presented. Meanwhile, some practical challenges, such as security, environment-friendly feature, steady usability, package, etc. were summarized. It is expected that the DREAM ink technology will initiate a series of unconventional applications in modern society, and even enter into peoples’ daily life in the near future.

Recent development in copula and its applications to the energy, forestry and environmental sciences

Investigation of hydrogen evolution activity for the nickel, nickel-molybdenum nickel-graphite composite and nickel-reduced graphene oxide composite coatings

Leontief’s input–output model (IOM) is a widely applied method for tracing energy or emissions embodied in economic activities. The economic IOM used in environmental science has aroused broad concerns from both economists and environmentalists. The aim of this study is to review the hotspots of application of IOM in the energy and environmental science fields based on a bibliometric method by using co-words network analysis. All 4938 publications in this study were retrieved from Science Citation Index, Social Science Citation Index, Conference Proceedings Citation Index – Science, and Conference Proceedings Citation Index – Social Science & Humanities. The keywords and frequently cited articles were studied to reveal the evolution of hot spots related to IOM applications in the field of energy and environment from 1998 to 2016. The features of the co-words network analysis of keywords were analyzed by four network indicators including modularity, number of clusters, closeness coefficient, and average path length. The results showed that “energy”, “CO2 emissions”, “GHG”, “LCA”, “industrial ecology”, “carbon footprint”, “China”, and “international trade” were the major application fields of IOM. In different stages the boundary of hot spots became overlapped and the whole network tightness became stronger. According to the analysis of frequently cited articles, we found those articles on CO2 or GHG emissions embodied in trade had been the most frequently cited articles since 2007 with negotiations on climate change. Based on our findings, using IOM to analyze important environmental problems is the key point to popularize IOM applications. Future research opportunities exist to apply IOM to wider environment issues, such as combined emissions and resources.

Hydrogen production from formaldehyde steam reforming using recyclable NiO/NaF catalyst