Optimizing zoning for ecological management in alpine region by combining ecosystem service supply and demand with ecosystem resilience.

In order to enhance ecosystem stability and promote sustainable regional ecological, social, and economic development, it is crucial to explore the coupling relationship between ecosystem service supply and demand and the resilience of ecosystem, so as to propose scientific ecological management zones and strategies. Taking the vulnerable alpine ecosystem in Gannan Tibetan Autonomous Prefecture (Gannan Prefecture) as the study area, this paper comprehensively utilized multi-source data, grid analysis, ecosystem service supply and demand estimation model, and coupled coordination model to analyze the spatio-temporal differentiation and coordination pattern of ecosystem service supply and demand in the study area from 2000 to 2020. With the assistance of the Analytic Hierarchy Process (AHP), the ecosystem resilience index system was constructed to evaluate the regional ecological resilience. The results reveal the following: (1) In the past 20 years, the ecosystem service supply and resilience in Gannan Prefecture showed a fluctuating upward trend, and the demand continued to grow steadily. Their spatial differentiation were obvious, but the pattern remained stable. (2) There was a moderate incoordination indicated by the average coordination degree of the supply and demand coupling of ecosystem services, which rangeed between 0.3 and 0.4. (3) Gannan Prefecture was split into three ecological management zones, considering the spatial distribution of ecosystem service supply and demand, as well as resilience. Through system function monitoring and other measures, the ecological conservation zone will rely on its high resilience to support the restoration and self-sufficiency of the system, ensuring the stability and well-being of the ecosystem. The primary objectives of general protected zone includes environmental preservation, strict regulations, and the prevention of human intervention. To enhance their ecological background, key restoration zone must intensify the implementation of ecological restoration initiatives. To address the needs of the locals, strategies such as ecological compensation, optimizing the land use structure, and fostering the growth of environmentally friendly companies can be implemented simultaneously.

Uniform-embeddable-distributed Ni3S2 cocatalyst inside and outside a sheet-like ZnIn2S4 photocatalyst for boosting photocatalytic hydrogen evolution.

The rational cocatalyst design is considered a significant route to boost the solar-energy conversion efficiency for photocatalytic H2 generation. However, the traditional cocatalyst-loading on the surface of a photocatalyst easily leads to scarce exposed active sites induced by the agglomeration of cocatalysts and a hindrance of the light absorption of the photocatalyst, thus significantly limiting the enhancement of the photocatalytic H2-generation performance. Herein, a new concept of uniform-embeddable-distributed cocatalysts is put forward. Consequently, uniform-embeddable-distributed cocatalysts of Ni3S2 were designed and constructed inside and outside of the nanosheet-like ZnIn2S4 photocatalyst to form a Ni3S2/ZnIn2S4 binary system (UEDNiS/ZIS). The unique uniform-embeddable-distributed Ni3S2 cocatalyst (UEDNiS) could provide abundant exposed active sites, facilitate the spatial separation and ordered transfer of charges inside and outside of ZnIn2S4 nanosheets, and reduce the hydrogen-adsorption free energy for photocatalytic H2-generation reactions. As a result, UEDNiS/ZIS exhibited a high photocatalytic H2-generation rate of 60 µmol h-1 under visible-light irradiation, almost 7.8 and 2.8 times higher than pristine ZnIn2S4 and the traditional surface-loaded Ni3S2/ZnIn2S4 (TSLNiS/ZIS), respectively. This work represents a new cocatalyst-design approach to realize high-efficiency hydrogen evolution in binary heterostructured photocatalytic systems.

2D PtS nanorectangles/g-C3N4 nanosheets with a metal sulfide-support interaction effect for high-efficiency photocatalytic H2 evolution.

Cocatalyst design is a key approach to acquire high solar-energy conversion efficiency for photocatalytic hydrogen evolution. Here a new in situ vapor-phase (ISVP) growth method is developed to construct the cocatalyst of 2D PtS nanorectangles (a length of ∼7 nm, a width of ∼5 nm) on the surface of g-C3N4 nanosheets. The 2D PtS nanorectangles/g-C3N4 nanosheets (PtS/CN) show an unusual metal sulfide-support interaction (MSSI), which is evidenced by atomic resolution HAADF-STEM, synchrotron-based GIXRD, XPS and DFT calculations. The effect of MSSI contributes to the optimization of geometrical structure and energy-band structure, acceleration of charge transfer, and reduction of hydrogen adsorption free energy of PtS/CN, thus yielding excellent stability and an ultrahigh photocatalytic H2 evolution rate of 1072.6 µmol h-1 (an apparent quantum efficiency of 45.7% at 420 nm), up to 13.3 and 1532.3 times by contrast with that of Pt nanoparticles/g-C3N4 nanosheets and g-C3N4 nanosheets, respectively. This work will provide a new platform for designing high-efficiency photocatalysts for sunlight-driven hydrogen generation.