Regional industrial redistribution and carbon emissions: a dynamic analysis for China

To facilitate and balance regional economic development and to reduce carbon emissions, China has implemented a series of policies to promote the redistribution of industries and economic activities across regions since 2000. This paper employs a logarithmic mean Divisia index (LMDI) to analyse the dynamic net effect on carbon emissions of Chinese policies promoting economic redistribution across sub-national regions, using a panel data of five sectors in 30 provinces during 1995–2017. The results of our analysis show that the redistribution of industry in particular, but also business and construction activities, leads to an increase in CO2 emissions, while the relocation of agriculture and transportation activities reduces emissions. We also find that the emission increase effect of the transfer of carbon intensive industries to new (host) regions is higher than the emission reduction effect induced by the agglomeration of clean industries in the original (home) regions. However, from 2014–2017, alongside the gradual industrial redistribution, China has also reduced aggregate CO2 emissions by 58.6 MT. In addition, the results show that population migration, which is due to redistribution of industry and other economic activity, has caused higher emission increases than emission reductions due to redistribution policies. We further calculate the marginal effect of industrial redistribution on CO2 emissions and draw out relevant policy implications. Industrial (and other economic activity) redistribution within a county can be not only an economic policy, but also an important policy instrument to mitigate CO2 emissions. This is the case in China.In the process of regional industrial redistribution, policymakers should aim to reduce the emission increase effect of transfer of carbon-intensive industries to host regions and to raise the emission reduction effect induced by an agglomeration of clean industries in home regions.Industrial redistribution is usually a long-term strategy for regional development within a county, and any reduction effects on CO2 emissions are likely to need time to appear. Industrial (and other economic activity) redistribution within a county can be not only an economic policy, but also an important policy instrument to mitigate CO2 emissions. This is the case in China. In the process of regional industrial redistribution, policymakers should aim to reduce the emission increase effect of transfer of carbon-intensive industries to host regions and to raise the emission reduction effect induced by an agglomeration of clean industries in home regions. Industrial redistribution is usually a long-term strategy for regional development within a county, and any reduction effects on CO2 emissions are likely to need time to appear.</p

Simultaneous Formation of Artificial SEI Film and 3D Host for Stable Metallic Sodium Anodes

Metallic sodium is a promising anode for sodium-based batteries, owing to its high theoretical capacity (1165 mAh g^–1) and low potential (−2.714 V vs standard hydrogen electrode). However, the growth of sodium dendrites and the infinite volume change of metallic sodium during sodium striping/plating result in a low Coulombic efficiency and poor cycling stability, generating a safety hazard of sodium-based batteries. Here, an efficient approach was proposed to simultaneously generate an artificial SEI film and 3D host for metallic sodium based on a conversion reaction (CR) between sodium and MoS₂ (4Na + MoS₂ = 2Na₂S + Mo) at room temperature. In the resultant sodium–MoS₂ hybrid after the conversion reaction (Na–MoS₂ (CR)), the production Na₂S is homogeneously dispersed on the surface of metallic sodium, which can act as an artificial SEI film, efficiently preventing the growth of sodium dendrites; the residual MoS₂ nanosheets can construct a 3D host to confine metallic sodium, accommodating largely the volume change of sodium. Consequently, the Na–MoS₂ (CR) hybrid exhibits very low overpotential of 25 mV and a very long cycle stability more than 1000 cycles. This novel strategy is promising to promote the development of metal (lithium, sodium, zinc)-based electrodes

3D-Printed Hierarchical Porous Frameworks for Sodium Storage

Exploring 3D printing in the field of sodium-ion batteries is a great challenge since conventionally inks cause unavoidably compact filaments or frameworks, which significantly hamper the infiltration of electrolyte and diffusion of big-size sodium ions (1.02 Å), resulting in low reversible capacities. Here, new hierarchical porous frameworks are 3D printed for sodium storage by employing well-designed GO-contained inks. The resultant frameworks possess continuous filaments, hierarchical multihole gridding. Such distinct properties render these frameworks able to facilitate the fast transportation of both sodium ion and electron. As a result, 3D-printed hierarchical porous frameworks reveal the high specific capacity as well as rate performance and periodic steadiness for up to 900 cycles for sodium storage

Influence of substituents and cooperativity in doubly hydrogen-bonded complexes of 2-pyridone and oxalic acid

<p>We performed a systemic investigation of the substitution and cooperative effects on the O–H···O and N–H···O H-bonds in the complexes of 2-pyridone and its derivatives with oxalic acid. Generally, the electron-withdrawing substituent in 2-pyridone weakens the O–H···O H-bond but strengthens the N–H···O H-bond, while the opposite effect is for the electron-donating group. In addition, the substitution effect is associated with its substitution position in 2-pyridone. The total interaction energy of a chainlike trimer with oxalic acid as a middle molecule exhibits some additivity. When oxalic acid combines with two 2-pyridone/2-pyridinethione molecules, the O–H···O/S H-bond is weakened but the N–H···O H-bond is enhanced. When three oxalic acid molecules are linked by the double O–H···O H-bonds, one H-bond with the middle oxalic acid as the proton donor is weakened and the other H-bond with the middle oxalic acid as the proton acceptor is strengthened.</p

Two-Dimensional Porous Sandwich-Like C/Si–Graphene–Si/C Nanosheets for Superior Lithium Storage

A novel two-dimensional porous sandwich-like Si/carbon nanosheet is designed and successfully fabricated as an anode for superior lithium storage, where a porous Si nanofilm grows on the two sides of reduced graphene oxide (rGO) and is then coated with a carbon layer (denoted as C/Si–rGO–Si/C). The coexistence of micropores and mesopores in C/Si–rGO–Si/C nanosheets offers a rapid Li⁺ diffusion rate, and the porous Si provides a short pathway for electric transportation. Meanwhile, the coated carbon layer not only can promote to form a stable SEI layer, but also can improve the electric conductivity of nanoscale Si coupled with rGO. Thus, the unique nanostructures offer the resultant C/Si–rGO–Si/C electrode with high reversible capacity (1187 mA h g^–1 after 200 cycles at 0.2 A g^–1), excellent cycle stability (894 mA h g^–1 after 1000 cycles at 1 A g^–1), and high rate capability (694 mA h g^–1 at 5 A g^–1, 447 mA h g^–1 at 10 A g^–1)

Vertically Aligned Sulfur–Graphene Nanowalls on Substrates for Ultrafast Lithium–Sulfur Batteries

Although lithium–sulfur batteries have gained great interest owing to their high energy density, they lack suitable electrodes capable of rapid charging and discharging to enable a high power density critical for wide applications. Here, we demonstrate a simply electrochemical assembly strategy to achieve vertically aligned sulfur–graphene (S-G) nanowall onto electrically conductive substrates. Remarkably, in each individual S-G nanowalls, sulfur nanoparticles are homogeneously anchored in between of graphene layers and ordered graphene arrays arrange perpendicularly to the substrates, which are favorable for the fast diffusions of both lithium and electron. Moreover, the hierarchical and porous structures facilate the effective accommodation of the volume change of sulfur. As a consequence, a high reversible capacity of 1261 mAh g^–1 in the first cycle and over 1210 mAh g^–1 after 120 cycles with excellent cyclability and high-rate performance (over 400 mAh g^–1 at 8C, 13.36 A g^–1) are achieved with these S-G nanowalls as cathodes for lithium–sulfur batteries, providing the best reported rate performance for sulfur–graphene cathodes to date

Highly Efficient Enrichment of Radionuclides on Graphene Oxide-Supported Polyaniline

Graphene oxide-supported polyaniline (PANI@GO) composites were synthesized by chemical oxidation and were characterized by SEM, Raman and FT-IR spectroscopy, TGA, potentiometric titrations, and XPS. The characterization indicated that PANI can be grafted onto the surface of GO nanosheets successfully. The sorption of U­(VI), Eu­(III), Sr­(II), and Cs­(I) from aqueous solutions as a function of pH and initial concentration on the PANI@GO composites was investigated. The maximum sorption capacities of U­(VI), Eu­(III), Sr­(II), and Cs­(I) on the PANI@GO composites at pH 3.0 and <i>T</i> = 298 K calculated from the Langmuir model were 1.03, 1.65, 1.68, and 1.39 mmol·g^–1, respectively. According to the XPS analysis of the PANI@GO composites before and after Eu­(III) desorption, nitrogen- and oxygen-containing functional groups on the surface of PANI@GO composites were responsible for radionuclide sorption, and that radionuclides can hardly be extracted from the nitrogen-containing functional groups. Therefore, the chemical affinity of radionuclides for nitrogen-containing functional groups is stronger than that for oxygen-containing functional groups. This paper focused on the application of PANI@GO composites as suitable materials for the preconcentration and removal of lanthanides and actinides from aqueous solutions in environmental pollution management in a wide range of acidic to alkaline conditions

Adsorption and Desorption of U(VI) on Functionalized Graphene Oxides: A Combined Experimental and Theoretical Study

The adsorption and desorption of U­(VI) on graphene oxides (GOs), carboxylated GOs (HOOC-GOs), and reduced GOs (rGOs) were investigated by batch experiments, EXAFS technique, and computational theoretical calculations. Isothermal adsorptions showed that the adsorption capacities of U­(VI) were GOs > HOOC-GOs > rGOs, whereas the desorbed amounts of U­(VI) were rGOs > GOs > HOOC-GOs by desorption kinetics. According to EXAFS analysis, inner-sphere surface complexation dominated the adsorption of U­(VI) on GOs and HOOC-GOs at pH 4.0, whereas outer-sphere surface complexation of U­(VI) on rGO was observed at pH 4.0, which was consistent with surface complexation modeling. Based on the theoretical calculations, the binding energy of [G^···UO₂]²⁺ (8.1 kcal/mol) was significantly lower than those of [HOOC-GOs^···UO₂]²⁺ (12.1 kcal/mol) and [GOs-O^···UO₂]²⁺ (10.2 kcal/mol), suggesting the physisorption of UO₂²⁺ on rGOs. Such high binding energy of [GOs-COO^···UO₂]⁺ (50.5 kcal/mol) revealed that the desorption of U­(VI) from the −COOH groups was much more difficult. This paper highlights the effect of the hydroxyl, epoxy, and carboxyl groups on the adsorption and desorption of U­(VI), which plays an important role in designing GOs for the preconcentration and removal of radionuclides in environmental pollution cleanup applications

Different Interaction Mechanisms of Eu(III) and ²⁴³Am(III) with Carbon Nanotubes Studied by Batch, Spectroscopy Technique and Theoretical Calculation

Herein the sorption of Eu­(III) and ²⁴³Am­(III) on multiwalled carbon nanotubes (CNTs) are studied, and the results show that Eu­(III) and ²⁴³Am­(III) could form strong inner-sphere surface complexes on CNT surfaces. However, the sorption of Eu­(III) on CNTs is stronger than that of ²⁴³Am­(III) on CNTs, suggesting the difference in the interaction mechanisms or properties of Eu­(III) and ²⁴³Am­(III) with CNTs, which is quite different from the results of Eu­(III) and ²⁴³Am­(III) interaction on natural clay minerals and oxides. On the basis of the results of density functional theory calculations, the binding energies of Eu­(III) on CNTs are much higher than those of ²⁴³Am­(III) on CNTs, indicating that Eu­(III) could form stronger complexes with the oxygen-containing functional groups of CNTs than ²⁴³Am­(III), which is in good agreement with the experimental results of higher sorption capacity of CNTs for Eu­(III). The oxygen-containing functional groups contribute significantly to the uptake of Eu­(III) and ²⁴³Am­(III), and the binding affinity increases in the order of <i>S</i><i>OH</i> < <i>S</i><i>COOH</i> < <i>S</i><i>COO</i>^–. This paper highlights the interaction mechanism of Eu­(III) and ²⁴³Am­(III) with different oxygen-containing functional groups of CNTs, which plays an important role for the potential application of CNTs in the preconcentration, removal, and separation of trivalent lanthanides and actinides in environmental pollution cleanup

3D Nitrogen-Doped Graphene Aerogel-Supported Fe₃O₄ Nanoparticles as Efficient Electrocatalysts for the Oxygen Reduction Reaction

Three-dimensional (3D) N-doped graphene aerogel (N-GA)-supported Fe₃O₄ nanoparticles (Fe₃O₄/N-GAs) as efficient cathode catalysts for the oxygen reduction reaction (ORR) are reported. The graphene hybrids exhibit an interconnected macroporous framework of graphene sheets with uniform dispersion of Fe₃O₄ nanoparticles (NPs). In studying the effects of the carbon support on the Fe₃O₄ NPs for the ORR, we found that Fe₃O₄/N-GAs show a more positive onset potential, higher cathodic density, lower H₂O₂ yield, and higher electron transfer number for the ORR in alkaline media than Fe₃O₄ NPs supported on N-doped carbon black or N-doped graphene sheets, highlighting the importance of the 3D macropores and high specific surface area of the GA support for improving the ORR performance. Furthermore, Fe₃O₄/N-GAs show better durability than the commercial Pt/C catalyst