Multiscale levels CO2 decouple reinforcement in China.

Decoupling economic growth from CO2 emissions is imperative for China. Meanwhile, establishing a consistent and comprehensive decoupling inventory that includes national (N), regional and provincial (RP), and city and county (CC) levels is essential for further policy formulation. This research aims to investigate the decoupling status using the "N-RP-CC" approach while considering changes in decoupling trends at the different levels. A combination of the Tapio decoupling model and cluster analysis is employed to study the decoupling's spatiotemporal characteristics and trends. The study first calculates the decoupling value for "national, 7; regions, 30; provinces, 1501 CCs" in China, 2006-2017. The results show that there continues to be an improvement in the decoupling trend at the national level. Conversely, the regional scale exhibits a more vulnerable decoupling trend compared to the national level, with weak and extended negative decoupling observed in northeastern and northern China. Moreover, provincial heterogeneities are increasingly evident, with poor decoupling statuses appearing in Jilin, Heilongjiang, Liaoning, and Xinjiang, as well as many central provinces. Additionally, although more than half of CCs exhibit weak decoupling during most years, seven different states of decoupling were also identified during the time frame. These findings further indicate that spatiotemporal heterogeneities extend beyond RP scales within CCs. Taking the Yangtze River as a boundary line reveals a severe situation in northern areas along with rapid development trends observed in southern regions. Finally, we clustered 1414 CCs based on their industrial proportions for 2017 which further highlights increasingly prominent heterogeneities that should be carefully considered. Based on these findings, policy recommendations such as spatial organization and optimization and technique investment are proposed to achieve CO2 emission decoupling under the N-RP-CC levels.

Supramolecular confinement pyrolysis to carbon-supported Mo nanostructures spanning four scales for hydroquinone determination.

Metal nanostructures with high atom utilization, abundant active sites, and special electron structures should be beneficial to the electrochemical monitoring of hydroquinone (HQ), a highly toxic environmental pollutant. However, traditional nanostructures, especially non-noble metals generally suffer from severe aggregation, or consist of a mixture of nanoparticles and nanoclusters, resulting in low detection sensitivity. Herein, we precisely control the size of Mo-based nanostructures spanning four scales (viz. Mo2C nanoparticles, Mo2C nanodots, Mo nanoclusters and Mo single atoms) anchored on N, P, O co-doped carbon support. The detection sensitivity of four samples toward the HQ follows the orders of Mo single atoms＞Mo2C nanodots＞Mo nanoclusters＞Mo2C nanoparticles. The catalytic ability of four catalysts is investigated, also showing the same order. The supported Mo single atoms show superior electro-sensing performance for HQ with wide linear range (0.02-200 µM) and low detection limit (0.005 µM), surpassing most previously reported catalysts. Moreover, the coexistence of dihydroxybenzene isomers of catechol (CC) and resorcinol (RC) does not interfere with the detection of HQ on the Mo single-atom sensor. This work opens up a polyoxometalate-based confinement pyrolysis approach to constructing ultrafine metal-based nanostructures spanning multiple-scales for efficient electrochemical applications.