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1.
J Colloid Interface Sci ; 676: 1068-1078, 2024 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-39079270

RESUMO

The development of efficient and cost-effective electrocatalysts to overcome the intrinsic sluggish kinetics of the oxygen reduction reaction (ORR) in zinc-air batteries is crucial. In this study, we introduce a strategy that integrates a template-assisted synthesis with subsequent thermal treatment to fabricate an active and stable cobalt-based nitrogen-doped carbon electrocatalyst, denoted as Co-N-CNT. The strategy adjusts the disordered architecture of the zeolitic imidazolate framework (ZIF) through the synergistic effect of bimetallic species, restricted the growth of zeolitic imidazolate framework nanoleaves (ZIF-L) using salt templates, and directed the transformation from a two-dimensional blade-like morphology to a three-dimensional multi-tiered composite structure. Notably, the Co-N-CNT-800 sample, synthesized at an optimized pyrolysis temperature of 800 °C, exhibits a half-wave potential of 0.89 V and demonstrates stability with sustained cycling over 21 h, which is comparable to the performance of commercial Pt/C electrocatalysts. Moreover, when employed as the cathode in zinc-air batteries, Co-N-CNT-800 not only surpasses Pt/C in terms of power density but also exhibits long-term charge/discharge stability. This findings offer a viable pathway for the design of active and cost-effective ORR electrocatalysts, holding promise for applications in the electrochemical energy storage and conversion systems.

2.
Nanotechnology ; 34(22)2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36857776

RESUMO

Oxygen evolution reaction (OER) is a necessary procedure in various devices including water splitting and rechargeable metal-air batteries but required a higher potential to improve oxygen evolution efficiency due to its slow reaction kinetics. In order to solve this problem, a heterostructured electrocatalyst (Co3O4@FeOx/CC) is synthesized by deposition of iron oxides (FeOx) on carbon cloth (CC) via plasma-enhanced atomic layer deposition, then growth of the cobalt oxide (Co3O4) nanosheet arrays. The deposition cycle of FeOxon the CC strongly influences thein situgrowth and distribution of Co3O4nanosheets and electronic conductivity of the electrocatalyst. Owing to the high accessible and electroactive areas and improved electrical conductivity, the free-standing electrode of Co3O4@FeOx/CC with 100 deposition cycles of FeOxexhibits excellent electrocatalytic performance for OER with a low overpotential of 314.0 mV at 10 mA cm-2and a small Tafel slope of 29.2 mV dec-1in alkaline solution, which is much better than that of Co3O4/CC (448 mV), and even commercial RuO2(380 mV). This design and optimization strategy shows a promising way to synthesize ideally designed catalytic architectures for application in energy storage and conversion.

3.
Artigo em Inglês | MEDLINE | ID: mdl-36232137

RESUMO

Environmental regulation (ER) plays an important role in urban low-carbon development (ULCD). First of all, we evaluate the ULCD level of 282 cities in China from 2005 to 2020 by constructing an index group and entropy method. Two panel models are then used to test the spillover effects and threshold effects of ER and industrial structure on ULCD. The results show that the ULCD level of most cities is still in grade III (0.27-0.38) or IV (0.38-0.49), and the level of central-western cities is generally lower than that of eastern cities. Furthermore, the spillover effect of ER and industrial structure upgrading (UIS) on ULCD is positive in eastern cities (0.038) but opposite in central or western cities (-0.024). Further results show that the positive effects of optimization of industrial structure (OIS) and UIS are gradually increasing with the improvement of ER. However, the positive effects are more beneficial to the eastern cities. Therefore, the conclusions of this study can provide a decision-making reference for local government to comprehensively formulate environmental and industrial policies to enhance the low-carbon development of cities.


Assuntos
Carbono , Indústrias , China , Cidades , Desenvolvimento Econômico , Reforma Urbana
4.
Artigo em Inglês | MEDLINE | ID: mdl-32059565

RESUMO

Cultivated land systems have an enormous ecological function value with respect to water conversation, nutrient circulation and climate regulation. The people's cognition, willingness and behavior may prove to be pivotal in ecologically protecting cultivated land. The purpose of this paper is to explore suppliers' and demanders' cognition, willingness and behavior with respect to the ecological protection of cultivated land. The second-order structural equation model was employed, and a five-point Likert scale was designed. Based on data obtained from a questionnaire surveyed on a sample of 460 (farming and no-farming households) from Caidian district, Wuhan, China, the results show that within/between suppliers and demanders, there are mismatches in willingness as well as behavior to ecologically protect cultivated land. In the suppliers group and in the demanders group, there are mismatches with respect to the interactive mechanism of cognition, willingness and behavior in the ecological protection of cultivated land. Three factors, subjective norms, attitude toward behavior, and perceived behavior control, affect willingness and behavior with respect to protection differently between the suppliers and the demanders. The "intermediary" effects of willingness and behavior in the ecological protection of cultivated land only appear in the demanders model, and are not significant in the suppliers model. In addition, another finding was that farmers' behavior as suppliers and demanders of ecological protection of cultivated land were mismatched. The article contributes firstly to exploring the ecological protection of cultivated land from the perspective of suppliers' and demanders' subjective psychology. Farmers with "dual roles" as suppliers and demanders should pay more attention to the ecological protection of cultivated land. Their cognition and skills in the ecological protection of cultivated land are in need of improvement. It is also necessary to bridge the gap between suppliers and demanders; access to the knowledge of the ecological value of cultivated land will incentivize their behavior with respect to the ecological protection of cultivated land.


Assuntos
Agricultura , Cognição , Conservação dos Recursos Naturais , Adulto , Idoso , Atitude , China , Fazendeiros , Feminino , Humanos , Masculino
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