Boosting High-Rate Zinc-Storage Performance by the Rational Design of Mn_(2)O_(3) Nanoporous Architecture Cathode

Manganese oxides are regarded as one of the most promising cathode materials in rechargeable aqueous Zn-ion batteries(ZIBs)because of the low price and high security.However,the practical application of Mn2O3 in ZIBs is still plagued by the low specific capacity and poor rate capability.Herein,highly crystalline Mn2O3 materials with interconnected mesostructures and controllable pore sizes are obtained via a ligand-assisted self-assembly process and used as high-performance electrode materials for reversible aqueous ZIBs.The coordination degree between Mn2+and citric acid ligand plays a crucial role in the formation of the mesostructure,and the pore sizes can be easily tuned from 3.2 to 7.3 nm.Ascribed to the unique feature of nanoporous architectures,excellent zinc-storage performance can be achieved in ZIBs during charge/discharge processes.The Mn2O3 electrode exhibits high reversible capacity(233 mAh g−1 at 0.3 A g−1),superior rate capability(162 mAh g−1 retains at 3.08 A g−1)and remarkable cycling durability over 3000 cycles at a high current rate of 3.08 A g−1.Moreover,the corresponding electrode reaction mechanism is studied in depth according to a series of analytical methods.These results suggest that rational design of the nanoporous architecture for electrode materials can effectively improve the battery performance.

Continuous polypyrrole nanotubes encapsulated Co_(3)O_(4)nanoparticles with oxygen vacancies and electron transport channels boosting peroxymonosulfate activation

Co_(3)O_(4)particles are promising heterogeneous catalysts for peroxymonosulfate(PMS)activation;whereas they still surfer from the extensive agglomeration,serious Co leaching,poor electronic conductivity,and difficult recovery.Herein,a novel hybrid nanoarchitectonic constructed by encapsulating Co_(3)O_(4)nanoparticles into continuous polypyrrole(PPy)nanotubes(Co_(3)O_(4)@PPy hybrids)was developed using electrospun fibers as the templates,which boosted the catalytic degradation toward tetracycline(TC).The continuous polypyrrole nanotubes could provide the confined spaces,offer effective electron transfer pathway,suppress cobalt ion loss,facilitate the oxygen vacancy(Ovac)formation,and accelerate the Co^(2+)/Co^(3+)cycles.Co_(3)O_(4)@PPy hybrids thereby exhibited a remarkably enhanced catalytic activity with the TC degradation efficiency of 97.2%(kobs=0.244 min^(−1))within 20 min and total organic carbon(TOC)removal rate of 66.8%.Furthermore,the recycle test,real natural water treatment,and fluidized-column catalytic experiments indicated the potential of Co_(3)O_(4)@PPy hybrids in the practical large-scale applications.

Understanding the relationships between poverty alleviation and ecosystem conservation:empirical evidence from western China

Despite growing interest in the use of Payments for Ecosystem Services(PES)for both social and ecological benefits,few studies have investigated the feedback and interaction between poverty alleviation and ecosystem protection outcomes.In this study,the poverty reduction effects of PES policies and their subsequent influence on environmental protection outcomes are investigated.To address these questions,222 local rural households who were involved in PES programs from the Habahu National Nature Reserve in western China were interviewed.The results showed that the social and ecological outcomes of PES policies are neither two separate entities nor a trade-off.While rural households are the key participants in PES programs,the social and ecological outcomes of PES policies are closely related to each other.In addition,poverty reduction results could greatly influence ecosystem conservation effects.Livelihood assets,as well as the attitudes of rural households,play important roles in both of the outcomes.This research provides a new perspective that considers the social and ecological benefits of PES policies,and it also calls for an integrated consideration of social and ecological components in tihe design of PES policies to achieve enhanced results both for poverty alleviation and ecosystem conservation.

Payments for watershed ecosystem services:mechanism,progress and challenges

Introduction:Payment for watershed ecosystem services(PWES),a policy instrument for compensating for the externality of watershed ecosystem/environmental services,has gained in policy importance in China over the past two decades.Many scholars and researchers have contributed to the conceptualization of this policy framework by developing operational mechanisms as well as compensation standards for PWES.Outcomes:This article reviews 27 PWES schemes piloted in China and in 10 other countries,with a particular emphasis on successful cases of land-use conversion programs,such as the Paddy Land to Dry Land Program and Sloping Land Conversion Program that have been implemented in China.Discussion:By comparing different cases,the authors attempt to answer the following questions:what were the ecological and institutional contexts in which these schemes were established and how did they work?What were the actual efficiencies and impacts of these piloted schemes?Which scheme worked better in certain ecological,socio-economic,and institutional contexts?Conclusion:Based on case studies,the authors draw the following conclusions about Chinese PWES:(1)to establish an acceptable standard for a PWES program,it is necessary to estimate the economic and social costs regarding the livelihoods of households;(2)multistakeholder negotiation mechanism for PWES,including intermediaries,such as the local government,NGO/NPOs,village committees,and user associations,should be used;(3)ES,non-market services,should acquire positive externalities to accomplish an optimal win–win pattern concerning both environmental goals and the livelihoods of local resource users.