The coupling coordination between tourism urbanization and ecosystem services value and its obstacle factors in ecologically fragile areas: a case study of the Wuling Mountain area of Hunan Province, China.

The interrelationship between tourism urbanization (TU) and the ecological environment is extremely complex. Some studies have analyzed the interaction between them but ignored the ecosystem services. Therefore, exploring the coupling coordination relationship between TU and ecosystem services value (ESV) is significant. In this research, we established a coupling coordination degree (CCD) model between TU and ESV and used exploratory spatial data analysis (ESDA), spatial variogram model, and obstacle degree model to evaluate the evolution characteristics of CCD and its obstacle factors in the Wuling Mountain area of Hunan Province (WMAHP). The results are as follows: (1) the comprehensive TU level shows an upward trend, and TU levels in the west are generally higher than in the east. The total ESV shows a fluctuating upward trend, and the average ESV is relatively low in the west and southeast. (2) The comprehensive CCD shows an increasing trend, and the coupling coordination relationship has changed from uncoordinated to coordinated in most counties. Spatially, the global spatial autocorrelation and spatial variation degree of CCD are insignificant. Wulingyuan and Yongding are uplift areas, and a subsidence area is in the southeast. It is worth noting that the problem of TU lag generally exists. (3) For the whole area, TU and economy are always the primary obstacle factors in the system and category layer, respectively, but the obstacle degree of the population has gradually increased. At the county level, TU restricts the CCD improvement in most counties, and the proportion of counties where the economy is the primary obstacle in the criterion layer exceeds 60%. Policymakers need to formulate targeted promotion strategies based on the coupling coordination and relative development level between TU and ESV for different counties. This paper provides valuable references for achieving coordinated development between TU and ESV in ecologically fragile areas worldwide.

Highly flexible reduced graphene oxide@polypyrrole-polyethylene glycol foam for supercapacitors.

A flexible and free-standing 3D reduced graphene oxide@polypyrrole-polyethylene glycol (RGO@PPy-PEG) foam was developed for wearable supercapacitors. The device was fabricated sequentially, beginning with the electrodeposition of PPy in the presence of a PEG-borate on a sacrificial Ni foam template, followed by a subsequent GO wrapping and chemical reduction process. The 3D RGO@PPy-PEG foam electrode showed excellent electrochemical properties with a large specific capacitance of 415 F g-1 and excellent long-term stability (96% capacitance retention after 8000 charge-discharge cycles) in a three electrode configuration. An assembled (two-electrode configuration) symmetric supercapacitor using RGO@PPy-PEG electrodes exhibited a remarkable specific capacitance of 1019 mF cm-2 at 2 mV s-1 and 95% capacitance retention over 4000 cycles. The device exhibits extraordinary mechanical flexibility and showed negligable capacitance loss during or after 1000 bending cycles, highlighting its great potential in wearable energy devices.

Efficient Photocatalytic Degradation of Malachite Green in Seawater by the Hybrid of Zinc-Oxide Nanorods Grown on Three-Dimensional (3D) Reduced Graphene Oxide(RGO)/Ni Foam.

A hybrid of ZnO nanorods grown onto three-dimensional (3D) reduced graphene oxide (RGO)@Ni foam (ZnO/RGO@NF) is synthesized by a facile hydrothermal method. The as-prepared hybrid material is physically characterized by SEM, XRD, Raman, and X-ray photoelectron spectroscopy (XPS). When the as-prepared 3D hybrid is investigated as a photocatalyst, it demonstrates significant high photocatalytic activity for the degradation of methylene blue (MB), rhodamine (RhB), and mixed MB/RhB as organic dye pollutants. In addition, the practical application and the durability of the as-prepared catalyst to degradation of malachite green (MG) in seawater are firstly assessed in a continuous flow system. The catalyst shows a high degradation efficiency and stable photocatalytic activity for 5 h continuous operation, which should be a promising catalyst for the degradation of organic dyes in seawater.