3E System Research Articles

Study of electrochemical behavior of rGO and Metal-Organic Framework nanocomposite electrodes for supercapacitive applications

Abstract This research studied the electrochemical performance of reduced Graphene Oxide (rGO) and a nanocomposite comprising rGO and Metal-Organic Framework-5 (MOF-5) for supercapacitor applications. The nanocomposite, synthesized through a solvothermal method, aimed to capitalize on the synergistic effects of combining rGO with MOF-5 under normal laboratory conditions without utilizing autoclave. By adjusting the concentration of the oxidizing agent, the oxidation degree of rGO was effectively regulated, thereby influencing its structural properties. Utilizing the optimized rGO, electrodes were fabricated for both rGO and MOF5-rGO configurations. Electrochemical studies were carried out using a three-electrode (3E) system with a 6M KOH electrolyte. The MOF-5, reduced graphene oxide (rGO), and MOF5-rGO nanocomposite samples were characterized using X-ray powder diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) to determine their chemical composition and structural information. The Electrochemical Impedance Spectroscopy (EIS) spectra show low internal resistance (Rs) and charge transfer resistance (Rct), indicating higher conductivity of rGO and nanocomposite. The rGO electrode in the 3E system showed a specific capacitance of 65 Fg-1 whereas MOF5-rGO displayed 73 Fg-1 at a current density of 1.2 Ag-1. MOF5-rGO nanocomposite demonstrates better capacitor retention (96%) compared to rGO (90%) at 5A/g. These results indicate that the MOF5-rGO sample is a promising electrode for supercapacitor application.

Multi-Scenario Research on the Coupled and Coordinated Development of the Economic–Energy–Environmental (3E) System under the Reconstruction of the Power System—New Exploration Based on the “Dual Triangle” Theory

Under the background of building a new-type power system, as the core of the energy system, the restructuring of the power system will inevitably have a linked impact on the coordinated development of the economy–energy–environment system. A “Dual Triangle” theoretical framework consisting of the “Energy Impossibility Triangle” and “Sustainable Development Triangle” was constructed in this paper. By combining historical statistical analysis with scenario predictive analysis, the historical characteristics of the “Dual Triangle” and future trends under different scenarios were analyzed, and the coupled interaction relationship of the “Dual Triangle” was also studied. Conclusions were as follows: The energy system gradually inclined towards economy and cleanliness from 2010 to 2022, and the operation status of the “Dual Triangle” was stable. A positive coupling relationship within the “Dual Triangle” in vigorously promoting renewable energy scenarios is close, which can be regarded as the preferred path for the reconstruction of the power system. The security and low-carbon phased development scenario is a development model that dynamically mitigates the challenges of the “Energy Impossibility Triangle”. Security has become the core contradiction of the “Energy Impossibility Triangle”. This paper conducts an integrated and innovative application of the “Dual Triangle” theory and provides a case basis for how to achieve the coupled interaction of the “Dual Triangle”.

Highly porous carbon with selective transformation of nitrogen groups boosts the capacitive performance through boric acid template assisted strategy

To address the extensive demand for energy storage, the development of unique carbon-based supercapacitors represents a viable solution. We successfully synthesize the unique boron (B), nitrogen (N)-containing porous carbon (denoted as BNPC) from reed biomass through one-step boric acid templated carbonization method, which are used as high-performance carbon electrode for electric double-layer capacitor (EDLC). By the synergistic effects of boric acid template and N-rich melamine, a well-balanced micro‐/meso-porous structure and abundant N and oxygen (O) heteroatoms within BNPC are readily obtained, exhibiting an ultrahigh specific surface area of 2619 m2·g−1. These distinctive natures endow BNPC electrode with the excellent capacitive behaviors, affording an outstanding specific capacitance of 396.8 F·g−1 at a three-electrode (3E) system with KOH electrolyte. Density functional theory (DFT) method is utilized to further clarify the interaction mechanism between K and designed graphene with various N configurations, revealing the significant roles of Pyridinc-N and Graphitic-N. The two-electrode (2E) symmetric supercapacitor assembled by BNPC electrodes in TEABF4 electrolyte demonstrates an extremely high energy density of 51.82 Wh·kg−1 at a power density of 375 W·kg−1 and great capacitance retention of 91 % after 6000 cycles. This reed-derived highly porous carbons display superior electrochemical performance, making it the ideal candidates for large capacity supercapacitors in practice.

Is the Economy, Environment and Energy (3E) System Sustainable?—An Analysis of the Coordination Degree of Carbon Decoupling and Energy Equity in the Yangtze River Economic Belt

As the climate crisis intensifies, the low-carbon transition seems to be the necessary path to maintain the sustainability of the 3E system. However, does it no longer pose potential threats to sustainability? In the context of the low-carbon transition, this study reveals hidden worries about the sustainability of the 3E system from an energy equity perspective, specifically focusing on the coordination between carbon decoupling and energy equity. This study innovatively calculates the level of carbon decoupling and energy equity in China’s Yangtze River Economic Belt from 2008 to 2019 and explores the degree of coordinated development between carbon decoupling and energy equity by employing the coupling coordination model and bivariate local Moran index. The results show the following: (1) from 2008 to 2019, the energy equity in the Yangtze River Economic Belt showed steady improvement, but the overall level was still not high, being below 0.5; (2) the upstream and downstream regions showed more obvious resistance in maintaining the coordinated development of carbon decoupling and energy equity, but there are structural differences among them; (3) inter-basin differences were an important feature of the low-carbon economy and equitable energy development in the Yangtze River Economic Belt in the past. This study provides policy implications and research insights for promoting the sustainability of the 3E system in transition countries from an energy equity perspective.

Zolmitriptan-functionalized graphene oxide and its composite with [Bmim][FeCl4] ionic liquid and biochar derived from the pyrolysis of Heracleum Persicum for supercapacitor application

Graphene oxide (GO) based electrodes often exhibit poor electrochemical performance due to agglomeration. Here, GO was functionalized with the expired heteroatom-rich pharmaceutical compound of Zolmitriptan (ZOL-FGO) as a redox-active spacer to alleviate the mentioned issue. Next, to enhance the electrochemical performance, KOH-activated biochar derived from Heracleum Persicum seeds (HP) through pyrolysis (as a reaction medium) and 1‑butyl‑3-methylimidazolium tetrachloroferrrate ([Bmim][FeCl4]) ionic liquid (IL) (as a conductivity enhancer) were synthesized and physically composited with the ZOL-FGO. Evaluation of the electrochemical behavior of ZOL-FGO/HP/IL electrode in a three-electrode (3E) system revealed the hybrid supercapacitor nature and recorded a specific capacitance (Cs) of 522 F g−1 at 1 A g−1 and a Cs retention of 97.3 % over 10,000 cycles at 8 A g−1. Moreover, the ZOL-FGO/HP/IL//ZOL-FGO/HP/IL electrode was designed and analyzed in the two-electrode (2E) system to determine its practicability. This electrode recorded a Cs of 245 F g−1 at 1 A g−1, a Cs retention of 95.3 % over 10,000 cycles at 8 A g−1, and a power density of 900 W kg−1 at the energy density of 41.35 Wh kg−1. The results confirmed that the synergistic effect of the synthesized materials could be promising in constructing a high-performance hybrid supercapacitor.

The development of E-Equation Easy System (3E System)

E-Equation Easy System (3E System) is a web-based system created to solve simultaneous equation calculations using the Matrix method (Cramer Rule Method) which is faster and easier as an alternative to manual calculation methods. This application will be able to be used by lecturers and students but the level and form of access are different to control the security of questions. This innovation project targets the following two objectives which are the first; to help lecturers in facilitating the preparation of theory and practical questions for students, and secondly, to reduce the calculation time required in providing accurate answers. In terms of the functionality of this innovation project, 3E System has been able to be used by students through an open user module and by lecturers through a registered user module. This application is also able to meet the calculation of solutions for two types of simultaneous equations, namely two variables and three variables, and it makes it easier for lecturers to get answer schemes and create simultaneous equation questions by just entering the values of the variables. The use of this application has indeed been able to help in solving the problems faced by lecturers in the implementation of the teaching and learning process. 3E system was developed using PHP as a chosen scripting language, MySQL as a database, Bootstrap as an open-source web user interface, Javascript and Cascading Style Sheets (CSS) are also attached with them. This system has also successfully gone through the testing phase and can be used online safely. This responsive system, can be accessible using a desktop or mobile phone, helps access from all over the world and can collect feedback from users regarding the level of satisfaction with the use of the system.

Multicity comparative assessment and optimized management path of sustainability of the economy-energy-environment system: A case study of core cities in China's three major economic circles.

Coordinated and stable development of economy-energy-environment (3E) systems represents a long-term strategy for the sustainable development of humankind. Following the research idea of "indicator system construction-3E system evaluation-obstacles identification-optimization management," this article innovatively constructs a multiangle and comparable methodology system for evaluation and optimized management of the 3E system and considers the core cities of three economic circles in China as cases for empirical research. The results show that all the coordination degree levels were of good or high quality, which was at the highest level in the country. The sustainability degree of the three cities showed an upward trend; of these, Beijing had the highest sustainability degree, followed by Guangzhou and Shanghai. Obstacle degree analysis shows that technology investment and energy factors were common factors hindering sustainable development of the 3E systems of the three cities, and each city also had its own unique factors that acted as obstacles. On this basis, this article formulates region-specific policy recommendations in order to provide a useful reference for top-level design for the government. Integr Environ Assess Manag 2024;20:875-887. © 2023 SETAC.

Could trade protectionism reshape the nexus of energy-economy-environment? Insight from different income groups

The Russian-Ukrainian conflict and the COVID-19 pandemic have triggered trade protectionism, which further accelerates the US isolationism and European populism. This study examines the impacts of trade protection on renewable energy, economic growth, and carbon emissions. Compared to previous studies, the role of trade openness is innovatively examined and heterogeneity is analyzed for different income groups. ssioThis study analyzes the impact of trade openness on the energy-economy-environment (3E) system of 123 countries through threshold effects using a panel threshold regression (PTR) model. The results show that there is a trade openness threshold for the impact of renewable energy consumption and economic growth, and then there is an inverse effect. That is, a U-shaped relationship exists between renewable energy and economic growth with the threshold effect of trade openness. While for the nexus of renewable energy and carbon emissions, there are two structural breakpoints. The inhibiting effect of renewable energy consumption on carbon emissions decreases as trade openness crosses the breakpoint. However, the effects of structural breakpoints in trade openness vary across income economies. Specifically, as trade openness has passed the structural breakpoint, renewable energy's role in promoting the economy in the middle- and high-income groups has gradually increased, while that in the low-income groups has fallen. The study recommends effective trade measures to minimize environmental damage and promote sustainable growth through the use of clean energy.

Long-term energy-environment-economic programming under carbon neutrality target: a study on China’s regional energy transition pathways and CO2 mitigation strategies

ABSTRACT Carbon neutrality is one of the key issues in mitigating global climate change. The carbon neutrality process accelerates the global energy transformation from fossil energy to renewable energy. Among the main indicators related to carbon neutrality proposed by the Chinese government, those directly related to energy include carbon emission intensity, the proportion of non-fossil energy consumption, and the total installed capacity of wind and solar power generation. It can be seen that the transformation of energy development is crucial for realizing carbon neutrality. Meanwhile, the correlation between carbon neutrality and economic development is not antagonistic. On the contrary, carbon neutrality can not only enhance the quality and efficiency of traditional industries but also improve the overall development of society. Therefore, the coordinated and sustainable developments of the energy - economy- environment (3E) system is the priority for achieving the target of carbon neutrality. However, the impact of carbon neutrality on regional development requires long-term consideration, which increases the difficulties of comprehensive planning. In this study, a long-term comprehensive programming model of regional energy and economic development under carbon peaking and carbon neutrality targets was established. A carbon neutrality assessment indicator (CNAI) framework was constructed to assess the effect of carbon neutrality actions in different regions. Meanwhile, a LEAP model was developed to simulate energy demand and carbon emissions. The multi-target weights determined by assessment results of CNAI and the parameters range set by LEAP model were the basis of the multi-objective optimization model to support regional development. Furthermore, the proposed method was applied to Shaanxi province in China, which offered quantitative targets and suggestions for energy structure transformation and industrial structure adjustment. The results show that coal and oil will account for 6.25% of the total energy consumption and the proportion of secondary industry will drop to 25.40% by 2060. The method established in this study provides a new scientific approach for resolving multi-objective trade-offs in long-term programming and determining a reasonable optimization range for regional development under climate mitigation policies.

Interaction mechanism and spatial effect of cross-regional haze pollution based on a multisectoral economy-energy-environment (3E) model and the evidence from China.

The transboundary characteristics and multisectoral factor interaction mechanism of haze pollution have aroused widespread attention but remain understudied. This article proposes a comprehensive conceptual model that clarifies regional haze pollution, further establishes a theoretical framework on a cross-regional, multisectoral economy-energy-environment (3E) system, and attempts to empirically investigate the spatial effect and interaction mechanism employing a spatial-econometrics model based on China's province-level regions. The results demonstrate that (1) regional haze pollution is a transboundary atmospheric state formed by the accumulation and agglomeration of various emission pollutants; moreover, there is a "snowball" effect and a spatial spillover effect. (2) The formation and evolution of haze pollution are driven by the multisectoral factors of 3E system interaction, and the findings still hold after theoretical and empirical analysis and robustness tests. (3) Significant spatial autocorrelation exists for the 3E factors, presenting different clustering modes with a dynamic spatiotemporal evolution, particularly in the high-high (H-H) mode and low-low (L-L) mode. (4) Significant heterogeneous impacts of economic and energy factors on haze pollution are identified, namely, an inverted "U-shaped" relationship and a positive linear association, respectively. Further spatial analysis demonstrates a strong spatial spillover and obvious path dependence among local and neighboring regions. Policymakers are advised to consider multisectoral 3E system interaction and cross-regional collaboration. Integr Environ Assess Manag 2023;00:1-19. © 2023 SETAC.

A spatial lagged multivariate discrete grey model for forecasting an economy-energy-environment system

To perform better future trend prediction for an economy-energy-environment (3E) system and address the shortcomings of traditional multivariate grey models, this paper introduces a spatial correlation term into the multivariate discrete grey model, thus creating the SLDGM(1,n) model, and improves the final calculation of the model according to the priority of new information. The validity of the SLDGM(1,n) model is assessed using data from the 3E system in North China, and the SLDGM(1,n) model is applied to predict the future trends of the 3E system in North China. The following conclusions are obtained. First, the introduction of the spatial correlation term and the improvement of the final calculation method are reasonable; the prediction accuracy of the multivariate grey model is improved, and multiple systems are modeled simultaneously. Second, the SLDGM(1,n) model calculates the spatial spillover effect, and according to the simulation results for North China from 2010 to 2019, Hebei's energy consumption and carbon emissions are subject to the largest influence from other provinces, while its economic development level is subject to the smallest influence, and the carbon emissions of Shanxi and Inner Mongolia are subject to a negative spatial influence effect. Third, the prediction results indicate that under the effect of spatial correlation, the energy consumption of all five provinces in North China will continue to rise; the carbon emissions of Beijing will gradually decline while the carbon emissions of the other four provinces will all gradually rise, and the per capita GDP of the five provinces is expected to increase by more than 50% by 2025.

Digital Economy and 3E Efficiency Performance: Evidence from EU Countries

Nowadays, sustainability has become an important and widely accepted concept. Energy conservation and emission reduction are closely related to sustainable economic development. Therefore, a 3E efficiency approach, based on the “Energy–Environmental–Economic” (3E) system, can assess the coordination relationships among these three factors from the perspective of energy conservation and emission reduction. The digital economy is a new driving force for economic growth, but few studies have dealt with the question on whether it affects 3E efficiency. The purpose of this paper is to examine the relationship between the digital economy and 3E efficiency in EU countries. The empirical results indicate that: (1) overall 3E efficiency of EU countries showed an upward trend from 2011 to 2019; (2) in terms of the relationship between the digital economy and 3E efficiency, the digital economy has direct and indirect (through economic growth) impacts on 3E efficiency; when GDP per capita exceeds EUR 15,580, the influence coefficient of the digital economy on 3E efficiency changes from negative to positive. This suggests that EU countries with different levels of economic development should adopt different strategies to ensure the simultaneous development of their digital economy and 3E efficiency.

Conceptual Analysis of the 3E System Based on New Human Capital Theory

The contradiction between energy supply and demand, environmental protection, and economic development is becoming more and more obvious. How to coordinate and balance the relations between energy, environment, and economy has become a common concern of scholars. In this context, the Energy-Environment-Economy (3E) system is gradually maturing, and up to now, the 3E system has been widely used in the evaluation of the development of various regions. In order to make the 3E system closer to the real social situation in the application, the measured results have more practical significance. Based on the new human capital theory, this paper summarizes and analyzes the relevant research literature, and discusses the influence of population on the three subsystems of energy, economy, and environment in the 3E system. It is found that population has an impact on each subsystem, among which it is worth noting that the impact of population on the environmental subsystem is diverse and complex, so the current situation of the 3E system is different from the theory. The article examines the impact of population on the 3E system in order to optimize and complement the 3E system.

Coupling coordination degree of environment, energy, and economic growth in resource-based provinces of China

Environmental deterioration by natural resources development has emerged as an important concern recently. To address this concern, we constructed a tri-system evaluation index for environment, energy, and the economy and used the entropy value method and the coupling coordination degree model to analyze spatiotemporal changes in the coupling and coordination of subsystems in 10 of China's resource-based regions between 2011 and 2020 and found that the coupling and coordination level of the energy–economy–environment (3E) system in China's resource-based regions is characterized by fluctuating growth with an overall positive developmental trend. The average coupling coordination level increased from 0.541 in 2011 to 0.643 in 2020, reaching the primary coupling coordination stage. Clear heterogeneity exists between various resource-based regions: eastern regions perform better than western, and western better than central. Eastern regions Guangdong, Shandong, and Tianjin achieved coordinated development, while Liaoning exhibits the lowest coupling coordination level. The western regions vary considerably: Shanxi exhibits the highest degree of primary coupling coordination, whereas Qinghai, on the verge of dysfunctional recession, exhibits the lowest. The central regions vary the least; all exhibit minimal coupling coordination. These facts indicate that to enhance the coupling coordination level of China's 3E system in an integrated manner, each region must formulate a differentiated optimization strategy to compensate for its developmental shortcomings.

An evolving energy-environmental-economic system towards coordination: Spatiotemporal features and key drivers

An energy-environmental-economic (3E) system evolving towards long-term sustainability is facilitated by the coordination within. The spatiotemporal evolution as well as key drivers of 3E system coordination (3ESC) quantified from synchrony of subsystems’ development remains elusive. Targeting 30 Chinese provincial regions covering 2011–2019, this study successively evaluates the development level, development speed, coordination index of subsystems and 3ESC based on a 26-index framework. Spatial econometric analysis and principal component analysis are adopted to examine the spatial clustering effect and extract the key drivers of 3ESC. The results indicate that the coordination index of each subsystem and 3ESC for all regions undergo significant increase. An upward trend in 3ESC (over 0.85) has spread into all regions. Beijing, Shanghai, Guangdong, Tianjin and Jiangsu keep the leading position. A transition from negative to positive appears to the spatial autocorrelation, with “High-High” regions gathering in the Yangtze River Delta and Shandong. Variations in the influence degree of the key drivers corroborate the progress of China in the transition towards spurring high quality economic development. Policy implications are revealed from the perspectives of restrictive subsystem and prior tasks for consolidating 3ESC to provide reference for synergizing subsystems and achieving regional sustainability.

A nonlinear interactive grey multivariable model based on dynamic compensation for forecasting the economy-energy-environment system

Achieving the goals of emissions intensity reduction and energy structure transformation while ensuring stable economic development is essential for sustainable development in China. Establishing a concise and accurate model for predicting the 3E (economy-energy-environment) system is beneficial for decision-makers in developing optimal long-term energy and environmental planning. Although previous studies have concentrated on the interaction of variables in the 3E system, frameworks for prediction have thus far been limited. In this paper, we develop a novel nonlinear interactive grey multivariable model based on dynamic compensation, denoted as DCNIGM1,N, to perform the prediction of the 3E system. More specifically, the proposed model innovatively takes into account nonlinear driving effects to elucidate nonlinear interactive relationships between the system variables. A dynamic compensation mechanism is introduced into the systematic grey modeling for the first time to adapt to a dynamic system. In addition, the Whale Optimization Algorithm (WOA) is employed to determine the optimal nonlinear parameters to improve the forecast accuracy. To evaluate the performance of the DCNIGM1,N model in forecasting the 3E system, two existing grey forecasting models, three statistical approaches, and three machine learning models are selected as the benchmark models. Moreover, two more cases with different variables of the 3E system are applied to verify the feasibility and effectiveness of the proposed model. Experimental results indicate that the DCNIGM1,N model possesses the most excellent performance in all cases, showing the effectiveness and generalizability of the proposed method. The prediction from 2019 to 2020 shows that carbon emissions, total energy consumption, and gross domestic product will grow steadily.

Can Fujian Achieve Carbon Peak and Pollutant Reduction Targets before 2030? Case Study of 3E System in Southeastern China Based on System Dynamics

Fujian Province has entered the golden period of industrialization and rapid economic development, and its economy and society are undergoing significant changes. An unreasonable industrial structure and rapid growth of energy consumption will result in a high pressure of carbon peak and environmental pollution in Fujian Province in 2030. How to improve energy efficiency, control environmental pollution, and achieve a carbon peak by 2030 while ensuring economic growth has become the focus of the attention of researchers and relevant policymakers. A disadvantage of the current 3E (Economy–Energy–Environment) system is that it has no quantitative basis for the selection of variables and no combined analysis of carbon emissions and environmental pollution, which is not conducive to paying attention to environmental pollution in the process of achieving carbon peak. Based on the STIRPAT (Stochastic Impacts by Regression on Population, Affluence, and Technology) model analysis results of environmental pollution and carbon emissions in Fujian Province, this paper established the 3E system model of Fujian Province to simulate three development scenarios and explored the EKC (Environmental Kuznets Curve). The results of the STIRPAT model showed that population, economic structure, and energy structure were the main influencing factors of environmental pollution and carbon emissions in Fujian Province. The 3E system simulation results showed that the current development scenario (scenario one) in Fujian Province is not sustainable, and the carbon peak and pollutant reduction cannot be achieved in 2030. A more stringent development scenario (scenario three) was required to achieve carbon peak and pollutant reduction on schedule. The trend of the carbon emission EKC curve in Fujian Province was different from that of environmental pollution. The carbon emission EKC curve of Fujian Province was a common inverted “U” shape, while the environmental pollution EKC curve had three shapes of “N”, “M,” and inverted “U”. This study can provide a quantitative method for selecting 3E system variables and a new method for establishing the 3E model, and provide a quantitative reference for Fujian Province to develop subsequent policies to control carbon emissions and environmental pollution.

Comprehensive Measurement of the Coordinated Development of China’s Economic Growth, Energy Consumption, and Environmental Conservation

Since the Industrial Revolution, fossil fuels have become the main energy source for economic development. However, fossil fuels have also been linked to serious environmental impacts. China has recently undergone rapid economic growth, but its development model demands large amounts of energy and causes severe pollution. Therefore, there has been a recent shift toward the development of coordinated strategies to achieve economic growth while minimizing energy consumption and preserving the environment. This study sought to explore the spatiotemporal evolution of the coordination degree between economic growth, energy consumption, and environmental conservation (i.e., the “3E” system) in China, thus establishing a basis to improve coordinated development and minimize regional differences. This study evaluated 30 Chinese provinces using mathematical models. Between 2000 and 2019, the coordinated development level of the components of the 3E system in China increased steadily but remained generally low. Clear spatial agglomeration was also identified at the provincial scale, with the highest values occurring on the east coast and lower values occurring in the west and middle provinces.

Optimization of the Beijing Economy-Energy-Emissions System 2021-2035: A Scenario Simulation Analysis Based on a System Dynamics Model.

This paper constructs an Economy-Energy-Emissions (3E) System Dynamics Model using the megacity of Beijing, China, as an example, to estimate the effects of different policy scenarios (including three single-policy scenarios and four combined-policy scenarios) on the core variables of Beijing's 3E system from 2021 to 2035. The results suggest two main points. (1) Following the current development trend, the proportion of the GDP represented by the added value of advanced high-precision industries (Gao Jing Jian in Chinese) will only be 43% in 2035, implying a limited role in promoting economic growth. Despite effective control of total energy consumption, fossil energy's share of total consumption will reach 57% by 2035, hindering the process of making the energy consumption structure cleaner and leading to failure to achieve the targeted inflection point in CO2 emissions by 2025. PM2.5 control shows some successful results and will decrease to 19 μg/m3 in 2035. However, a gap compared to other world-class cities remains. (2) The implementation of a single policy for either industrial structure optimization, energy structure transformation, or emissions control cannot simultaneously meet the goal of high-quality coordinated development of Beijing's 3E system, whereas the comprehensive implementation of policies in all three dimensions is demonstrably effective.

Nanoarchitectonics of GO/PANI/CoFe2O4 (Graphene Oxide/polyaniline/Cobalt Ferrite) based hybrid composite and its use in fabricating symmetric supercapacitor devices

The synthesis of graphene-based hybrid electrode material provides a prime share in supercapacitor device material application. Here, we have synthesized a new type ternary composite GO/PANI/CoFe2O4 (Graphene Oxide/polyaniline/Cobalt Ferrite) by the oxidative-polymerization method with superior electrochemical behaviour. The analysis like X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), and Energy-dispersive X-ray spectroscopy (EDS) confirm the successful formation of material. The hybrid composite GO/PANI/CoFe2O4 gives the highest specific capacitance value of 781.27 F/g at scan rate of 1 mV/s and 346.92 F/g at current density of 1 A/g from 3E (three-electrode) and symmetric 2E (two-electrode) device system. The system exhibits a wide 1.2 V potential window. From the symmetric system, the ternary GO/PANI/CoFe2O4 had high specific energy (Esp) of 69.38 Wh/kg at 1 A/g and high specific power (Psp) of 5989.37 W/kg at 20 A/g along with 79.03 % retention of its original capacitance after 5000 cycles. The ternary material also showed a less Rct value of 8.51 Ω. The synergic effect of the individual components in the hybrid composite is the main factor for its excellent electrochemical behaviour.