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The development of low‐cost and efficient electrolyzer components is crucial for practical electrochemical carbon dioxide reduction (ECR). In this study, facile non‐woven cellulose‐based porous transport layers (PTLs) were developed for high current density CO2‐to‐CO conversion. By depositing a cobalt phthalocyanine (CoPc) catalyst‐layer over the PTLs, we fabricated ECR‐functioning gas‐diffusion‐electrodes (GDEs) for both flow‐cell and zero‐gap electrolyzers. Under optimal conditions, the Faradaic efficiency of CO (FECO) reached 92 % at a high current density of 200 mA cm−2. Furthering the architecture of the GDEs, CoPc was incorporated into the initial PTL slurry, forming ECR‐active PTLs without the need for an additional catalyst‐layer. The new GDE‐architecture favored the CoPc‐distribution by enhancing the contact and interactions with the carbon substrate and demonstrated a stable electrolysis process for over 50 h in a zero‐gap cell at 200 mA cm−2 with a FECO of 80 %. [ABSTRACT FROM AUTHOR]

In this work, a paper-based hydrogen fuel cell is developed without the need for hydrogen storage. Instead, an embedded aluminum foil inside the paper is utilized for in-situ hydrogen generation. The electrodes and current collectors are also deposited on the paper, leading to a lightweight, compact and flexible hydrogen fuel cell with an OCV reaching 0.93 V and a peak power density of 4 mW cm−2. Benefited from the impeded hydroxyl ion diffusion, the hydrogen generation rate is well controlled, leading to a high faradaic efficiency of 72%. In addition, the cell can be operated under different bending angles with negligible power loss. Furthermore, it can be conveniently stacked in the same piece of paper for higher voltage and power outputs. Such a novel fuel cell design is especially suitable for powering various flexible devices with small rated power. • A paper-based hydrogen fuel cell is developed with an OCV of 0.93 V. • The peak power density is 4 mW cm−2 and the maximum current density is 8 mA cm−2. • Faradaic efficiency and energy efficiency are as high as 72% and 18%, respectively. • 75–87.5% of the cell performance remains when bended by angles from 45° to 135°. • A 4-cell stack is developed with an OCV of 3.8 V and a stacking efficiency of 90.6%. [ABSTRACT FROM AUTHOR]

In this study, a novel mesoporous CdS/TiO 2 /SBA-15@carbon paper composite membrane was developed to enhance the visible-light responsive CO 2 photoreduction in an optofluidic membrane microreactor. The microscopic morphological and pore volume characterizations indicated that the incorporation of the mesoporous SBA-15 into the membrane development could greatly improve the specific surface area and pore volume. The optofluidic membrane microreactor with the newly-developed composite membrane was evaluated in terms of the methanol concentration and yield. Experimental results showed that the optofluidic membrane microreactor with mesoporous CdS/TiO 2 /SBA-15@carbon paper composite membrane yielded much better performance than did the one without the mesoporous SBA-15. For a given total amount of TiO 2 /SBA-15 in the composite membrane, too high dosage of TiO 2 in the composite membrane caused the reduction in the specific surface area and pore volume, thereby lowering the photocatalytic performance. In addition, it was found that the methanol concentration and yield firstly increased and then decreased with increasing the liquid flow rate. The increase of both the light intensity and NaOH concentration was able to enhance the methanol generation. The obtained results fully demonstrate the superiority of the newly-developed CdS/TiO 2 /SBA-15@carbon paper composite membrane for the CO 2 photoreduction. [ABSTRACT FROM AUTHOR]

A portable paper‐based organic redox flow primary battery using sustainable quinone chemistry is presented. The compact prototype relies on the capillary forces of the paper matrix to develop a quasi‐steady flow of the reactants through a pair of porous carbon electrodes without the need of external pumps. Co‐laminar capillary flow allows operation Under mixed‐media conditions, in which an alkaline anolyte and an acidic catholyte are employed. This feature enables higher electrochemical cell voltages during discharge operation and the utilization of a wider range of available species and electrolytes and provides the advantage to form a neutral or near‐neutral pH as the electrolytes neutralize at the absorbent pad, which allows a safe disposal after use. The effects of the device design parameters have been studied to enhance battery features such as power output, operational time, and fuel utilization. The device achieves a faradaic efficiency of up to 98 %, which is the highest reported in a capillary‐based electrochemical power source, as well as a cell capacity of up to 11.4 Ah L−1 cm−2, comparable to state‐of‐the‐art large‐scale redox flow cells. [ABSTRACT FROM AUTHOR]

A naturally occurring water‐soluble cobalt‐complex cyanocobalamin (Vitamin B12) has been identified as a new and efficient electrocatalyst for the CO2‐to‐CO reduction reaction in aqueous solution. Heterogeneous B12‐electrocatalysts prepared by a simple electrochemical immobilization technique on graphene‐oxide (GO)‐modified glassy carbon and carbon paper (CP) electrodes, without any non‐degradable polymer‐binders, showed a highly stable and well‐defined surface‐confined redox peak at E'=−0.138 V vs. RHE with a surface‐excess value, ΓB12=4.28 nmol cm−2. This new electrocatalyst exhibits 93 % Faradaic efficiency for CO2‐to‐CO conversion at an electrolysis potential, −0.882 V vs. RHE (an optimal condition) with a high current density, 29.4 mA cm−2 and turn‐over‐frequency value, 5.2 s−1, without any surface‐fouling problem, in 0.5 m KHCO3. In further, it follows an eco‐friendly, sustainable and water‐based approach with the involvement of biodegradable and non‐toxic chemicals/materials like B12, GO and CP. [ABSTRACT FROM AUTHOR]

Molecular catalysts have been shown to have high selectivity for CO2 electrochemical reduction to CO, but with current densities significantly below those obtained with solid‐state materials. By depositing a simple Fe porphyrin mixed with carbon black onto a carbon paper support, it was possible to obtain a catalytic material that could be used in a flow cell for fast and selective conversion of CO2 to CO. At neutral pH (7.3) a current density as high as 83.7 mA cm−2 was obtained with a CO selectivity close to 98 %. In basic solution (pH 14), a current density of 27 mA cm−2 was maintained for 24 h with 99.7 % selectivity for CO at only 50 mV overpotential, leading to a record energy efficiency of 71 %. In addition, a current density for CO production as high as 152 mA cm−2 (>98 % selectivity) was obtained at a low overpotential of 470 mV, outperforming state‐of‐the‐art noble metal based catalysts. [ABSTRACT FROM AUTHOR]

The October 2024 issue of Engineering Sustainability features six papers covering topics such as responsible sourcing in the AEC sector, using construction waste in mortar, asphalt pavement repair technologies, prefabricated subway station construction, residential block morphology impact on thermal comfort, and floating solar photovoltaic systems on hydro reservoirs. The papers provide insights, experimental studies, literature reviews, and analyses on various sustainable engineering practices and technologies. The research aims to improve sourcing processes, enhance mechanical properties of materials, explore alternative repair technologies, and promote sustainable energy generation for efficient and eco-friendly infrastructure development. [Extracted from the article]

It is of great significance to reveal the detailed mechanism of neighboring effects between monomers, as they could not only affect the intermediate bonding but also change the reaction pathway. This paper describes the electronic effect between neighboring Zn/Co monomers effectively promoting CO2 electroreduction to CO. Zn and Co atoms coordinated on N doped carbon (ZnCoNC) show a CO faradaic efficiency of 93.2 % at −0.5 V versus RHE during a 30‐hours test. Extended X‐ray absorption fine structure measurements (EXAFS) indicated no direct metal–metal bonding and X‐ray absorption near‐edge structure (XANES) showed the electronic effect between Zn/Co monomers. In situ attenuated total reflection‐infrared spectroscopy (ATR‐IR) and density functional theory (DFT) calculations further revealed that the electronic effect between Zn/Co enhanced the *COOH intermediate bonding on Zn sites and thus promoted CO production. This work could act as a promising way to reveal the mechanism of neighboring monomers and to influence catalysis. [ABSTRACT FROM AUTHOR]

• Dendritic In-doped Cu@Cu 2 O catalyst is prepared by co-electrodeposition method. • Doped-In content can tailor Cu+/Cu0 ratio, charge distribution, morphology and ECSA. • Cu+/Cu0 ratio plays a vital role on enhancing FE CO and partial current density at low In doping. • 3.7% In-Cu sample shows the highest FE CO of 87.6 ± 2.2 % and j CO of 9.7 ± 1.04 mA cm -2. Element doping is an effective strategy to enhance the selectivity of electrochemical carbon dioxide reduction. In this work, a dendritic core-shell In-doped Cu@Cu 2 O catalyst is prepared by co-electrodeposition method on carbon fiber paper for selective electroreduction of CO 2 to CO. Faradaic efficiency of producing CO over this dendritic In-doped Cu@Cu 2 O reaches 87.6 ± 2.2% with total current density of 11.1 ± 0.85 mA cm−2 at −0.8 V vs RHE, which outperforms most of the reported Cu-based electrocatalysts. The excellent performance is mainly derived from charge re-distribution and the enhanced intrinsic activity due to the formation of In-doped Cu 2 O layer. Meanwhile, the Cu+/Cu0 can be adjusted by tailoring the doped-In content. The relatively high ECSA and small charge transfer resistance are also conducive to improve the selectivity and activity. The oxyphilic In metal incorporated into the copper lattice can well stabilize the intermediate *COOH through enhancing interaction with O-ends of *COOH. This work provides a facile approach and a deep insight on design and synthesis of high efficiency hybrid electrocatalysts. [ABSTRACT FROM AUTHOR]

The photochemical and photoelectrochemical reduction of CO2 is a promising approach for converting carbon dioxide into valuable chemicals (materials) and fuels. A key issue is ensuring the accuracy of experimental results in CO2 reduction reactions (CO2RRs) because of potential sources of false positives. This paper reports the results of investigations on various factors that may contribute to erroneous attribution of reduced-carbon species, including degradation of carbon species contained in photocatalysts, residual contaminants from synthetic procedures, laboratory glassware, environmental exposure, and the operator. The importance of rigorous experimental protocols, including the use of labeled 13CO2 and blank tests, to identify true CO2 reduction products (CO2RPs) accurately is highlighted. Our experimental data (eventually complemented with or compared to literature data) underline the possible sources of errors and, whenever possible, quantify the false positives with respect to the effective conversion of CO2 in clean conditions. This paper clarifies that the incidence of false positives is higher in the preliminary phase of photo-material development when CO2RPs are in the range of a few 10s of μg gcat−1 h−1, reducing its importance when significant conversions of CO2 are performed reaching 10s of mol gcat−1 h−1. This paper suggests procedures for improving the reliability and reproducibility of CO2RR experiments, thus validating such technologies. [ABSTRACT FROM AUTHOR]

• Defect-rich mesoporous hierarchical nanostructure is in situ constructed. • A record mass-normalized formate production rate is achieved. • Broken local spatial symmetry brings about structural disorders and defects. • Improvement is due to componential and structural configuration of Bi/Bi 2 O 3. • Bi/Bi 2 O 3 junction contributes to CO 2 adsorption, activation and protonation. Electrocatalytic reduction of CO 2 to formate is believed as one of the most technologically and economically viable strategies for valuable fuels and chemical productions. Defect-rich Bi/Bi 2 O 3 nanosheets in situ grown on the carbon fiber papers (Bi/Bi 2 O 3 -CP) are directly used as an integrated cathode for CO 2 RR. Bi/Bi 2 O 3 -CP exhibits a high mass-normalized formate partial current density of 32.4 and 50.7 mA∙mg−1 cm−2 at −0.87 and −0.97 V, respectively, with high formate faradic efficiency of about 90 %. Incredibly, this cathode gives a record mass-normalized formate production rate of 1.12 mmol∙mg-1 cm-2 h-1 at −1.17 V, which exceeds drop-casted sample (0.41 mmol∙mg−1 cm−-2 h−1 at −1.17 V) and most state-of-the-art Bi based electrocatalysts. The boosted formation generation could be attributed to the unique mesoporous 3D hierarchical nanostructure with the integrated contributions of abundant defects and synergistic coordination of regionally disordered Bi/Bi 2 O 3 metal/oxide junction. [ABSTRACT FROM AUTHOR]

Constructive defect engineering has emerged as a prominent method for enhancing the performance of photocatalysts. The mechanisms of the influence of defect types, concentrations, and distributions on the efficiency, selectivity, and stability of CO2 reduction were revealed for this paper by analyzing the effects of different types of defects (e.g., metallic defects, non-metallic defects, and composite defects) on the performance of photocatalysts. There are three fundamental steps in defect engineering techniques to promote photocatalysis, namely, light absorption, charge transfer and separation, and surface-catalyzed reactions. Defect engineering has demonstrated significant potential in recent studies, particularly in enhancing the light-harvesting, charge separation, and adsorption properties of semiconductor photocatalysts for reducing processes like carbon dioxide reduction. Furthermore, this paper discusses the optimization method used in defect modulation strategy to offer theoretical guidance and an experimental foundation for designing and preparing efficient and stable photocatalysts. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the role of excited-state hydrogen bonding in the photocatalytic carbon dioxide reduction reaction (CO2RR) utilizing Rose Bengal as a catalyst, through a combined experimental and theoretical approach. Experiments validated the successful conversion of CO2 to CO in a homogeneous aqueous solution system under light irradiation, without additional photosensitizers or sacrificial agents. Theoretically, the DFT/TDDFT calculations modeled the catalyst-reactants as a hydrogen-bonded complex (HBC), understanding the energy, hydrogen, and electron transfer mechanisms induced by excited-state hydrogen bonding. Combining the photophysical and photochemical insights revealed the complete catalytic cycle, identifying the water oxidation process as the rate-limiting step in the entire photocatalytic CO2RR process. Experimental and computational results provide molecular-level insights into the structure–activity relationships. This work enhances comprehension of the pivotal role of excited-state hydrogen bonding and holds significant reference value for enhancing the conversion efficiency in the photocatalytic CO2RR. [ABSTRACT FROM AUTHOR]

A global transition to low-carbon, resource-efficient economies is occurring in response to risks posed by climate change and environmental degradation. Hydrogen is proposed as a zero-carbon substitute for natural gas with the potential to reduce carbon emissions in homes and businesses. Trades, including gasfitting, will be affected by the transition to a low-carbon economy and require upskilling to develop competencies to work with hydrogen to ensure safety and support domestic uptake. Understanding the training needs of trades practitioners is essential to the successful transition to a zero-carbon economy. This paper presents findings from a qualitative study of Australian gasfitters, exploring what motivates gasfitters to participate in training, what informs their ongoing learning and what their preferences are for hydrogen training. Most gasfitters are either self-employed or work in small businesses, and, as such, this context presents both challenges and opportunities to consider in upskilling strategies. Drawing on interview findings and literature on small business learning, the paper presents considerations to inform training approaches and policies in the transition to hydrogen and also, more broadly, for upskilling other small trade businesses similarly affected by a shift to low-carbon and green technologies. [ABSTRACT FROM AUTHOR]

The ongoing climate changes have determined governing bodies from all around the globe to set ambitious targets for CO2 reduction. In recent years, renewable energy technologies have proven themselves to be a method of CO2 reduction that is competitive in terms of both costs and efficiency, which led to the technologies becoming affordable and practical for residential use. Since the adoption of the Clean Energy for all Europeans Package in 2019, consumers were encouraged to have an active role in the power sector. This has led to the emergence of a new participant in the energy system, the power aggregator. From the scientific literature that has been covered so far, many articles focus on the economic benefits that different aggregator business models bring to the aggregators, their clients, and the system. Other scientific papers focus on optimizing how aggregators participate in energy markets by taking into consideration the technologies included in their portfolios and pricing mechanisms. Regardless of the subjects tackled, the articles mostly present theoretical aspects since, in practice, residential power aggregators are still not present in many countries. For all the reports that have been turned in so far, secondary research was carried out to gain a better understanding of the current power sector context. Renewable energy technologies were reviewed to uncover synergies that would prove valuable for power aggregator portfolios, existing business models of aggregators were examined to have a grasp on regulatory and economic limitations, and academic papers related to mathematical optimization models were studied. The doctoral research, for which this paper presents the progress, aims to use secondary research to understand aggregators at a European level and then to perform primary research into implementing the aggregating activity in Romania in the context of an accelerated shift to a decentralized power system. [ABSTRACT FROM AUTHOR]

This study provides a comprehensive review of recent advancements in photocatalytic and electrocatalytic carbon dioxide reduction using titanium dioxide catalysts. The basic concepts of light absorption, electron transport, and reduction processes are introduced in this paper, which also delves into the specifics of photocatalytic and electrocatalytic reduction of carbon dioxide. The paper highlights the key applications and benefits of titanium dioxide, including its strong stability, outstanding light absorption capacity, and good electron transport performance, in the photocatalytic and electrocatalytic reduction of carbon dioxide. Furthermore, it examines the impact of various surface modification techniques on catalytic performance, as well as the effects of various titanium dioxide catalyst forms on catalytic activity and selectivity in carbon dioxide reduction. The in‐depth analysis exhibit promising catalytic properties and hold significant potential for future advancements. However, some obstacles still need to be overcome, such as increasing catalytic activity and selectivity while minimizing energy dissipation. In order to improve catalytic performance and efficiency, future research should prioritize the optimization of structural design and surface modification techniques for catalysts. Additionally, the paper provides a scientific foundation for accomplishing sustainable carbon conversion, it also calls for additional experimental and theoretical research into the mechanism of action for titanium dioxide catalyst. [ABSTRACT FROM AUTHOR]

Electrochemical carbon dioxide reduction reaction (ECO2RR) is an effective means to promote carbon cycling. Recently, Bi-based metal–organic frameworks (MOFs) have attracted significant attention due to their high efficiency for formic acid generation in ECO2RR, however, their composition and morphology transformation during electrocatalysis still lack a deep exploration. Herein, a Bi-MOF with 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine (H3TATB) ligand is used as the prototype to investigate its in situ transformation during ECO2RR. With various characterization methods, the detailed transformation processes are revealed. Firstly, the Bi-MOF was transformed into Bi2O2CO3 due to ligand substitution in KHCO3 electrolyte, resulting in changes in both shape and composition. Secondly, during ECO2RR, the Bi3+ ions can be reduced into metallic Bi0 nanoparticles and act as the real active component for ECO2RR. The resultant catalyst exhibits a high selectivity of up to 94.3% towards formate generation. At an optimal potential of −1.08 V vs. RHE, the catalyst can maintain a current density of −25 mA cm−2 and a faradaic efficiency of formate over 90% for 14.5 hours. This work not only develops an efficient electrocatalyst for ECO2RR but also provides a new insight into the in situ reconstruction of MOF precursor into the active catalyst, which is useful for the design and synthesis of other materials. [ABSTRACT FROM AUTHOR]

At present, China is faced with double-challenge of pollution control and carbon dioxide emission reduction, and "reducing pollution and carbon" has become an important grip of the social and economic green transformation. In this paper, against the background of "reducing pollution and carbon", the gray water footprint and carbon emissions originated from the inter-regional trading of 30 provincial regions in China in 2012 and 2017 were analyzed using a multi-regional input-output tables of 2012 and 2017 respectively, and from the perspective of network relationship, the inter-provincial gray-water footprint and the nature of carbon dioxide spatial correlation network were analyzed empirically using the social network analysis method. Consequently, it was showed that the gray-water footprint and carbon dioxide emissions were greater in the regions with larger economic scale such as Shandong, Henan and Jiangsu provinces, in contrast the regions of lesser economic scale such as Hainan, Qinghai and Ningxia, the grey-water footprint and carbon dioxide emissions were smaller. Shanxi and Inner Mongolia were the main regions where net gray-water footprint and carbon emission outflowed, while Guangdong, Zhejiang and Jiangsu are the main regions net gray water footprint inflowed, and the degree of regional development and transportation factors were the main reasons for those differences; and the inter-provincial grey-water footprint and CO2 spatial correlations in all of the regions were within the spatial correlation network, and the individual characteristics indicated that the regions of small economic scale in northwest were dominated by spillover effect, and for the regions of larger economic scale, the relationship of receiving the spillover were the main feature, which had been caused by the flow of products or services. Hopefully, the results obtained from the study could provide a basis for the formulation of scientific water resources management and carbon reduction policy. [ABSTRACT FROM AUTHOR]

Carbon dioxide emissions from the transport sector make a significant contribution to global greenhouse gases, and understanding the factors that influence these emissions is beneficial for devising effective emission reduction policies. Oil prices are an important influencing factor since the fuel used in the transport sector is primarily based on oil, and fluctuations in oil prices directly impact the sector's CO2 emissions. Additionally, environmental policies, as a key means of controlling CO2 emissions, can affect the relationship between oil prices and CO2 emissions in the transport sector. Therefore, this study aims to examine the impact of oil prices on CO2 emissions in the transport sector and explore the nonlinear role of environmental policy stringency in this relationship. Based on data from 27 OECD member countries and 6 non-member countries from 1990 to 2019, we used the environmental policy stringency index as a threshold variable to construct a panel threshold regression model. The analysis results indicate a double-threshold effect: when the environmental policy stringency index is low, the impact of oil prices on CO2 emissions in the transport sector is not significant. However, when the index reaches the first threshold, the impact of oil prices significantly increases; upon reaching the second threshold, the effect is further intensified. This paper also analyzes the three subindicators—market-based policies, non-market-based policies, and technology support policies—to clarify the distinct impact mechanisms of different types of environmental policies. Finally, based on the research findings, we propose policy recommendations to achieve carbon dioxide emission reduction targets in the transport sector. [ABSTRACT FROM AUTHOR]

In this work, two novel ZnII- and CoII-porphyrin monomers with thiophene-based units attached via flexible 1,3-aminothiopropylene linkers were successfully synthesized and fully characterized. Electropolymerization of these monomers was performed on indium tin oxide (ITO)-coated glass and carbon paper via cyclic voltammetry (CV) to obtain the corresponding polymer films for photophysical characterization and investigation of their catalytic activities for the electrochemical reduction (ECR) of carbon dioxide (CO2), respectively. CV and controlled potential electrolysis (CPE) in a 0.5 M KHCO3 aqueous solution showed that the ZnII-porphyrin-based polymer mainly supports hydrogen (H2) evolution from water splitting, while the CoII-porphyrin-based polymer predominately promotes the formation of carbon monoxide (CO). At a reduction potential of −0.66 V vs. reversible hydrogen electrode (RHE), equivalent to an overpotential of −0.54 V, CPE under the catalysis of the CoII-porphyrin-based polymer could efficiently convert CO2 to CO with the optimum faradaic efficiency, turnover number (TON) and turnover frequency (TOF) of 66%, 5.7 × 102 and 1.6 s−1, respectively, after 1 h. The 6 h CPE suggests satisfactory film stability and steady production of CO from the ECR of CO2, indicating the potential use of this polymer film for the reduction of CO2 at a low overpotential under ambient conditions in aqueous media. [ABSTRACT FROM AUTHOR]

Reducing the use of fossil fuels is critical to human society. In recent years, electrocatalytic carbon dioxide (CO2) reduction has attracted widespread attention. A suitable CO2 reduction catalyst is essential to convert CO2 into more valuable chemical products with high selectivity and efficiency. In this paper, a highly selective ZnAlCe-Ternary metal hydroxides (ZnAlCe-THs) nanocomposite electrocatalyst material was designed and prepared, and its performance as an electrocatalyst for catalytic reduction of CO2 to carbon monoxide (CO) was explored. The layered structure of ZnAlCe-THs nanocomposites facilitates electron transfer as well as CO2 and proton transfer, providing a high specific surface area for the electroactive sites of the electrocatalytic reduction reaction. At the same time, the ZnAlCe-THs catalyst generates CO at an overpotential of − 0.5 V. At − 1.2 V versus the reversible hydrogen electrode (vs. RHE), the bias current density is about 10.46 mA cm−2 with high selectivity of 89.3% Faraday efficiency. Its excellent electrochemical properties make it a good catalyst for the selective reduction of CO2 to CO. In this paper, ZnAlCe-Ternary mental hydroxides (ZnAlCe-THs) with a layered hydrotalclike structure were prepared by hydrothermal and co-precipitation methods. It showed excellent catalytic performance in the electrocatalytic reduction of carbon dioxide to carbon monoxide with a Faraday efficiency of 89.3% at − 1.2 V vs. RHE and a current density of 10.46 mA cm−2 for higher selectivity for CO. In addition, the ZnAlCe-THs catalyst is stable and it can operate for 5 h without particularly significant deactivation. [ABSTRACT FROM AUTHOR]

Electrochemical conversion of CO2 to alcohols is one of the most challenging methods of conversion and storage of electrical energy in the form of high-energy fuels. The challenge lies in the catalyst design to enable its real-life implementation. Herein, we demonstrate the synthesis and characterization of a cobalt(III) triphenylphosphine corrole complex, which contains three polyethylene glycol residues attached at the meso-phenyl groups. Electron-donation and therefore reduction of the cobalt from cobalt(III) to cobalt(I) is accompanied by removal of the axial ligand, thus resulting in a square-planar cobalt(I) complex. The cobalt(I) as an electron-rich supernucleophilic d8-configurated metal centre, where two electrons occupy and fill up the antibonding dz2 orbital. This orbital possesses high affinity towards electrophiles, allowing for such electronically configurated metals reactions with carbon dioxide. Herein, we report the potential dependent heterogeneous electroreduction of CO2 to ethanol or methanol of an immobilized cobalt A3-corrole catalyst system. In moderately acidic aqueous medium (pH = 6.0), the cobalt corrole modified carbon paper electrode exhibits a Faradaic Efficiency (FE%) of 48 % towards ethanol production. Electrochemical conversion of carbon dioxide to ethanol is one of the most challenging energy conversion reactions. Here the authors show selective electroreduction of carbon dioxide to ethanol by using a functionalized cobalt A3-corrole catalyst immobilized on a carbon paper electrode. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to quantify the level of new-type urbanization and unravel the spatial and nonlinear effects of new-type urbanization and technological innovation on industrial carbon emissions. Although the impact of traditional urbanization levels on carbon emissions has been widely studied, there is still a huge room for optimization, and the impact of new-type urbanization on carbon emissions has not yet been clarified. Selecting 37 cities in the Yangtze River Delta as a research sample, this paper measures the new-type urbanization based on an evaluation system we build. Consequently, we assess the spatial and nonlinear effects of new-type urbanization and technological innovation on carbon emissions by the spatial Durbin model and non-parameter addictive model, respectively. The results indicate that the new-type urbanization and low-carbon city pilot policy have significant spatial spillover effects on reducing carbon dioxide emissions, while the economic growth plays a positive role in increasing carbon emission. As for nonlinear effects, there is a significant inverted "N"-shaped relationship between the level of new-type urbanization and carbon dioxide emissions, while the nexus between technological innovation and carbon emissions is an inverted "U"-shaped relationship. This paper provides a new perspective for confirming the mechanism of the new-type urbanization on carbon emissions. Meanwhile, these findings are of significance for the relevant authorities in China to develop appropriate policy in carbon dioxide emission reduction. [ABSTRACT FROM AUTHOR]

3D Bi2O3 fractal nanostructures (f‐Bi2O3) are directly self‐assembled on carbon fiber papers (CFP) using a scalable hot‐aerosol synthesis strategy. This approach provides high versatility in modulating the physiochemical properties of the Bi2O3 catalyst by a tailorable control of its crystalline size, loading, electron density as well as providing exposed stacking of the nanomaterials on the porous CFP substrate. As a result, when tested for electrochemical CO2 reduction reactions (CO2RR), these f‐Bi2O3 electrodes demonstrate superior conversion of CO2 to formate (HCOO−) with low onset overpotential and a high mass‐specific formate partial current density of −52.2 mA mg−1, which is ≈3 times higher than that of the drop‐casted control Bi2O3 catalyst (−15.5 mA mg−1), and a high Faradaic efficiency (FEHCOO−) of 87% at an applied potential of −1.2 V versus reversible hydrogen electrode. The findings reveal that the high exposure of roughened β‐phase Bi2O3/Bi edges and the improved electron density of these fractal structures are key contributors in attainment of high CO2RR activity. [ABSTRACT FROM AUTHOR]

With their rich surface chemistry, high electrical conductivity, variable bandgap, and thermal stability, 2D materials have been developed for effective electrochemical energy conversion systems over the past decade. Due to the diversity brought about by the use of transition metals and C/N pairings, the 2D material MXene has found excellent applications in many fields. Among the various applications, many breakthroughs have been made in electrocatalytic applications. Nevertheless, related studies on topics such as the factors affecting the material properties and safer and greener preparation methods have not been reported in detail. Therefore, in this paper, we review the relevant preparation methods of MXene and the safer, more environmentally friendly preparation techniques in detail, and summarize the progress of research on MXene-based materials as highly efficient electrocatalysts in the electrocatalytic field of hydrogen precipitation reaction, nitrogen reduction reaction, oxygen precipitation reaction, oxygen reduction reaction, and carbon dioxide reduction reaction. We also discuss the technology related to MXene materials for hydrogen storage. The main challenges and opportunities for MXene-based materials, which constitute a platform for next-generation electrocatalysis in basic research and practical applications, are highlighted. This paper aims to promote the further development of MXenes and related materials for electrocatalytic applications. [ABSTRACT FROM AUTHOR]

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Catalytic synthesis of urea is a bright substitutable to Haber–Bosch progression and industrial urea synthesis. Electrochemical C–N coupling of carbon dioxide and nitrogen oxides under environmental conditions is a newly developed method, which also provides a novel opinion for solving nitrate contamination. Conjugated organic frameworks (COFs) have been used as prospective electrocatalysts for nitrogen reduction reactions and carbon dioxide reduction reactions (CO2RR) as a result of their regulate structure and multihole properties, resulting in efficient electron transfer. This paper reports the efficient synthesis of urea from carbon dioxide and nitrate over MoM1S-Pc-M2PPs COF (M as a transition metal) electrocatalyst. According to the calculation of DFT, it was found that it was difficult for carbon dioxide and nitrogen oxide to coadsorb on MoM1S-Pc to synthesize urea, so we chose to synthesize CO on the metal porphyrin (M2PPs) structural unit, and then overflow on the bimetallic phthalocyanine and nitrogen oxide to synthesize urea. The possibility of nitrate adsorption on different catalysts was verified by calculation. We screened the stability, nitrate adsorption strength, and catalytic activity of MoM1S-Pc candidates, and the results showed that the most promising candidate catalyst was MoFeS-Pc. At the same time, the CO2RR M2PPs substrate was also screened, and the VPPs structure was selected as the best. In the study of coupling between different nitrogen-containing intermediates and *CO, the C–N coupling mechanism shows that *NOH and *CO are two possible C–N coupling nitrogen intermediates, which are shown to be thermodynamically spontaneous and have an inferior activation barrier. This study not only provisions novel perceptions into urea synthesis by coupling nitrogen oxides with carbon dioxide under environmental conditions, but also paves the way for boosting the sustainable production of carbon and nitrogen-coupled products. [ABSTRACT FROM AUTHOR]

Renewable energy resources (wind, solar) are unpredictable, so it is wise to store the electricity they generate in an energy carrier X. Various PtX (power to useful energy-intensive raw material such as hydrogen, synthetic natural gas, fuel) applications have been proposed. At the heart of our work is widely used idea to convert residual CO2 from biogas plant into higher hydrocarbons using electricity from renewables (e.g., sun, wind, hydro). The specific goal is to produce ethylene-highly demanded hydrocarbon in plastics industry. The process itself is realised on electrocatalytic carbon/copper cathode which must be selective to reaction: 2CO2 + 12e− + 12H+→C2H4 + 4H2O. We propose a bottom-up approach to build catalyst from the smallest particles-graphene sheet stacks (GSS) coated with metallic copper nanocrystals. Composite GSS-Cu structure functions as a CO2 and proton absorber, facilitating hydrogenation and carbon–carbon coupling reactions on Cu-nanocluster/GSS for the formation of C2H4. In our design electrocatalytic electrode is made from nitrogen-doped graphene sheet stacks coated with copper nanostructures. The N-GSSitself can be drop-casted or electrophoretically incorporated onto the carbon paper and gas diffusion electrode. Electrochemical deposition method was recognized as successful and most promising to grow Cu nanocrystals on N-GSS incorporated in conducting carbon substrate. Gaseous products from CO2 electro-catalytic reformation on the cathode were investigated by mass-spectrometer but the electrode surface was analysed by SEM/EDS and XRD methods. [ABSTRACT FROM AUTHOR]

In many photocatalytic reaction paths, the breaking of the first CO bond in a CO2 molecule is often the key step that becomes the rate‐controlled reaction step. In this paper, a graphitic carbon nitride (g‐C3N4) supported nickel single‐atom catalyst (Ni@g‐C3N4) was successfully constructed, and the mechanism of CO2 catalytic reduction was systematically studied based on density functional theory (DFT). The introduction of nickel promotes the adsorption of small molecules, especially for the CO2 activation. According to density of states (DOS) and frontier orbital analysis, the photogenerated carriers tend to jump from nitrogen atoms to carbon atoms, forming an electron transfer in real space, after g‐C3N4 is excited by light. With the appearance of nickel‐doped levels, the DOS of Ni@g‐C3N4 is no longer symmetric with respect to the spin up and down, especially around the original band gap of g‐C3N4. Single‐atom nickel has abundant frontier orbitals and high activity and is a favourable place for chemical reactions. The presence of surface hydrogen can promote the recovery of CO2, and the energy barrier of Ni@g‐C3N4 with hydrogen is only 15% of the clean g‐C3N4 surface. This paper provides a new idea for the development of efficient single‐atom catalysts for CO2 reduction. [ABSTRACT FROM AUTHOR]

Currently, there is considerable interest in developing cost‐effective, high‐performance electrocatalysts for electrocatalytic carbon dioxide reduction (ECR). Due to their low electrical conductivity and relatively weak catalytic activity, layered bimetallic oxides have rarely been applied in ECR studies. However, they contain a large specific surface area and are rich in Lewis bases, which are favorable for CO2 adsorption. Herein, F and N co‐doped layered bimetallic oxide and reduced graphene oxide composites with precisely controlled morphology are deposited directly on carbon paper using a simple constant current electrodeposition method (FN‐NA‐CLDH@RGO‐X, X denotes the deposition time). Notably, the doping of F helps to suppress the hydrogen precipitation reaction, while the doping of N enhances the adsorption and conversion of CO2. The CO2 reduction study in an H‐type electrolytic cell shows that the FN‐NA‐CLDH@RGO‐100 s electrode‐reduced CO2 to CO at an applied potential of −1.1 V with an efficiency of 87.9% (compared to the reversible hydrogen electrode). In addition, the doping of F favors the reduction of overpotential and the improvement of catalytic activity, while the synergistic effect of F and N enhances the catalytic activity without significant decay in more than 6 h of continuous testing. [ABSTRACT FROM AUTHOR]

Electrochemical conversion of CO 2 into valuable chemicals and fuels has emerged as a promising approach to achieving the net-zero emission target. In this work, bismuth (Bi)-based gas diffusion electrodes (GDEs) are prepared via scalable inkjet printing of the precursor on carbon papers, and subsequent thermal treatment. The optimization of the GDEs aims at the efficient CO 2 reduction to formate (HCOO−) with good selectivity and high current density. Ex situ FESEM, XRD, and XPS analyses evidence the morphological and structural transformations of Bi-based catalysts during electrolysis. In situ Raman spectroscopy illustrates the dynamic evolution of the electrocatalysts in a range of potentials. The complete procedure is represented as the transformation of Bi 2 O 3 polyhedral microcrystals to a flower-like assembly of Bi 2 O 2 CO 3 nanoflakes when exposed to KHCO 3 electrolyte under electrochemical conditions, and then to metallic Bi at more negative potentials (< −0.6 V vs. RHE). The evolution of Bi-GDEs confirms that metallic Bi nanostructure provides abundant active sites for selective conversion of CO 2 to HCOO−, and is highly promising for applications at industrially relavant scales. [Display omitted] • Bismuth-based gas diffusion electrodes are prepared via scalable inkjet printing of the precursor on carbon papers. • Ex situ analyses evidence the morphological and structural transformations of Bi 2 O 3 polyhedrons to Bi 2 O 2 (CO 3) nanoflakes. • In situ Raman spectroscopy illustrates the dynamic evolution of Bi 2 O 2 (CO 3) nanoflakes to metallic Bi during electrolysis. [ABSTRACT FROM AUTHOR]

To achieve the goal of urban carbon dioxide emission reduction, how to increase carbon sequestration has become a top priority. The biological sink is mainly divided into green carbon sink and blue carbon sink. Coastal cities have two kinds of carbon sinks. There, the study of carbon sinks in coastal cities is the primary choice to cope with climate change. Therefore, this study chooses coastal cities with primary industries including agriculture, fishery, and forestry as the study subjects. The LMDI (Log-Mean Divisia Index) method and multiple regression prediction models were used to explore the low-carbon countermeasures which increase urban net carbon sink from the perspective of influencing factors and future potential. The study found that the average output value of employees in the primary industry is the main driving factor, and the change in the purchasing power of unit carbon sinks and the change in the proportion of employees in the primary industry have inhibited the increase in net carbon sinks. Projections based on the primary industry's output and afforestation area as independent variables show an overall upward trend in net carbon sinks, reaching 15.70 million tons of net carbon sinks in 2060, offsetting 10–20% of total carbon emissions in the same year. Based on the calculation results, this paper puts forward some corresponding countermeasures to increase carbon sinks. This paper provides a theoretical reference for the low-carbon development of coastal cities in China, and the strategies can be also expanded to other cities with similar resources around the world. [ABSTRACT FROM AUTHOR]

In this paper, a methodology and optimization using the artificial bee colony (ABC) algorithm for life cycle cost (LCC) assessment of photovoltaic (PV) system for some Indian smart cities have been presented. Smart cities are the urban areas that utilize solar power PV system with other advanced innovations. The life cycle cost with and without carbon credit earned due to solar power generation in particular smart city should be known. Smart cities aim to assist local bodies in assessing their present energy consumption and future demand. This paper also focuses on PV energy generation, savings, and efficiency with cost. Four smart cities have been selected for LCC estimation on different field condition basis. The results show that in Srinagar, energy production is maximum, i.e., 435MWh, and LCC is minimum INR4125 million with an 8.9% rate of return on it. Therefore, net carbon dioxide emission reduction per annum for smart PV system over a lifetime of 20 years is 76.5 tCO2e on the overall thermal energy and 17.7 tCO2e on the overall exergy gain. LCC of smart PV system for different years has been estimated and optimized using the ABC algorithm, and the results show a 50.24% reduction in LCC. With the proposed approach, future opportunities for smart cities with smart PV system can be revealed. [ABSTRACT FROM AUTHOR]

This article discusses a variety of more recent alternatives to Portland cement (OPC) that can lower energy consumption and greenhouse gas emissions. Some of these new binders can be made utilizing fuels and low-grade industrial waste. Only after thorough examination of various physico-mechanical, microstructural, and durability properties can the practical viability of these alternative binders be substantiated.In this review paper seven important alternative cementitious binder systems i.e. Supplemental cementitious in place of OPC in some cases, Industrial By-Products, Alternative cements, Concrete Made Using Garbage as Aggregate, Carbona table Calcium Silicate Cement, Cements With a Calcium Hydro silicate Base, Eggshell waste for sustainable construction materials are discussed. It was deduced that all of the more recent cementitious binders could be created utilizing industrial wastes such as low-grade limestone or clay, fly ash, and slags. This would result in the achievement of the desired physico-mechanical and durability properties, as well as a decrease in cost and energy consumption of between 20 and 58 percent. In addition, the creation of the aforementioned alternative binder results in a reduction of greenhouse gases that is anywhere from 15–55%. [ABSTRACT FROM AUTHOR]

Energy storage technology is the key to achieving a carbon emission policy. The purpose of the paper is to improve the overall performance of the combined cooling, heating and power-ground source heat pump (CCHP-GSHP) system by the battery. A new operation strategy (the two-point operation) is proposed by controlling the power generation unit work. The power generation unit has two operation modes of non-operation and rated efficiency operation by the storage electricity battery. The new operation strategy is compared with the traditional CCHP-GSHP that without a battery. The optimization goals include the primary energy saving ratio, the reduction ratio of carbon dioxide emissions, and the annual total cost saving ratio. The independent GSHP system is used as a reference system. Multipopulation genetic algorithms are selected to achieve the problem of optimization. A hotel building is selected for a case study. The optimal configuration of the coupling system is computed following the electric load strategy. Finally, the results show that the CCHP-GSHP system has a better performance under the new operation strategy compared with the traditional CCHP-GSHP (the primary energy saving ratio increases by 5.5%; the annual carbon dioxide emission reduction ratio increases by 1%; the annual total cost reduction ratio increases by 5.1%). This paper provides reference and suggestions for the integration and operation strategy of CCHP-GSHP in the future. [ABSTRACT FROM AUTHOR]

Electrocatalytic CO2 reduction is regarded as a green and promising technology because it can convert carbon dioxide into value-added fuel or chemicals in a flexible and sustainable way. This research aimed to comprehensively analyze the research hotspots and trends in the field of CO2 electroreduction from 2005 to 2022 using bibliometric methods based on the core database of Web of Science. The results showed that 4546 papers on CO2 electroreduction were retrieved from 2005 to 2022, with a clear increasing trend. The research direction was diversified, involving multiple disciplines, and it is a comprehensive research field. ACS Catalysis is the journal with the largest number of articles. China is the country with the largest number of documents and has made significant contributions to the development and progress of this field. Copper-based catalysts are still the research focus in recent years. It is of great practical significance to develop copper-based catalysts with high efficiency, low cost, high stability, and high selectivity for the preparation of C1 products. [ABSTRACT FROM AUTHOR]

Ocean acidification forecasting has important implications for studying global carbon dioxide emissions reductions. However, due to seasonal and cyclical features, ocean acidification forecasting remains an extremely challenging task. Therefore, this paper proposes a grey wolf optimized fractional-order-accumulation discrete grey seasonal model (GFSM(1,1)). The GFSM(1,1) model improves the prediction of ocean acidification in two ways. The new information priority of seasonal data is improved by the fractional accumulation operator, and the adaptability of the grey model to seasonal data is increased by seasonal item parameters. The above two works have significantly improved the prediction accuracy of the grey prediction model for ocean acidification. The prediction results in practical cases prove that the prediction effect of the GFSM(1,1) model is not only better than the existing grey models (FMGM(1,N). NSGM(1,N), and GM(1,1)) but also better than statistical models (Nonlinear regression and ARIMA), traditional neural network model (LSTM) and deep learning model (SVM). Finally, the GFSM(1,1) model is applied to the prediction of seawater acidification. The forecast results show that the ocean will be acidified at a rate of 0.001863 per year, and the pH of the ocean will decrease by about 0.03% per year compared to the same period in previous years. [ABSTRACT FROM AUTHOR]

Intense efforts are currently being devoted to discovering cost-effective catalysts for the selective reduction of carbon dioxide (CO2). Many advances have indeed been achieved in the design of molecular complexes containing second coordination chemical functionalities that have contributed to boosting the homogeneous electrocatalytic activity. The introduction of such chemical facets in heterogeneous catalysis is still lacking. Here, we report the electrocatalytic properties of a chemically modified electrode with a molecular iron-porphyrin catalyst holding urea functions (UrFe) in CO2 reduction, acting as a multipoint hydrogen bonding cleft to enhance CO2 binding. The immobilization of UrFe on multiwall carbon nanotubes (MWCNTs)/carbon paper (CP) allows the investigation of the catalytic performance in water. We found, herein, that the modified electrode displays excellent selectivity towards CO production in water, which is also acting as the sole proton source. Importantly, we observed one of the highest effective turnover frequency (eTOF) values (>21 s−1) at a potential of −0.78 V vs. RHE in comparison with similar modified electrode containing bare iron-porphyrin analogues. Our results therefore point to a remarkable gain in electrocatalytic performance of molecular catalysts at the surface of the electrodes with the added dimensionality of chemical functions operating as molecular clefts towards the binding and reduction of CO2. [ABSTRACT FROM AUTHOR]

Photocatalytic reduction of CO 2 is a promising technology to capture CO 2 and convert it into solar fuels simultaneously. However, current photoreactors usually face the problems of low specific surface area, non-uniform light distribution and poor photon transfer. To address these issues, a novel optofluidic membrane microreactor with high surface-area-to-volume ratio, enhanced photon and mass transport and uniform light distribution was proposed in this work by combining optofluidics with the membrane reactor technology for the photocatalytic reduction of CO 2 with liquid water. A TiO 2 /carbon paper composite membrane was prepared as the photocatalytic membrane via coating TiO 2 onto the carbon paper followed by hydrophobic treatment by poly-tetrafluoroethylene (PTFE) for the separation of the gas/liquid phases. The performance of the proposed optofluidic membrane microreactor was evaluated by measuring the methanol yield. The effects of the liquid water flow rate, light intensity and catalyst loading on the methanol yield were also studied. It was shown that a maximum methanol yield of 111.0 μmole/g-cat·h was achieved at a flow rate of 25 μL/min and under the light intensity of 8 mW/cm 2 , which is among the top in comparison to the reported data. Results obtained fully demonstrate the feasibility and superiority of the proposed optofluidic membrane microreactor for the photocatalytic reduction of CO 2 . [ABSTRACT FROM AUTHOR]