Large-scale three-dimensional (3D) CdS nanocrystals with a flowerlike morphology were synthesized by a
facile hydrothermal treatment from Cd(NO3)2, thiourea, and hexamethylenetetramine [(CH2)6N4, HMT], where
HMT acted as a capping agent. The reaction conditions influencing the synthesis of these 3D CdS nanocrystals
such as initial precursor ratios, reaction time, reaction temperatures, and capping agents were studied and
optimized. The morphology, structure, and phase composition of CdS nanostructures were examined by X-ray
diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and high-resolution TEM. The formation mechanism
of the 3D CdS nanocrystals with flowerlike structure was proposed based on the results, which may pave the
way to shape-controlled synthesis of inorganic nanocrystals with 3D complex structures. The room-temperature
photoluminescence (PL) of the obtained CdS nanocrystals was also studied.
Abstract:The rapid growth of NO x emissions in China is mainly due to intensive fossil fuel consumption. In order to control NO x emissions, a multiyear NO x emission inventory was established by a bottom-up approach for the period 2000-2010. The results showed that NO x emissions increased by 2.1 times from 11.81 million tons (Mt) in 2000 to 24.33 Mt in 2010. We found that NO x emissions had exceeded SO 2 emissions in 2009 by comparison with their emission trends. We also found that the unbalanced NO x emissions in Eastern China and Western China are mainly due to the different gross regional product and industrial structure. Accounting for 70% of total energy consumption in China, coal is the largest NO x emission source among all the fossil fuels. In addition, the increased use of diesel and gasoline has spurred the increase of NO x emissions from the transportation sector. Manufacturing, electricity production, and transportation together composed about 90% of the national NO x emissions. Meanwhile, energy consumption and NO x emissions in China are predicted to be 3908.5 Mt standard coal equivalent (SCE) and 19.7 Mt in 2020 with this scenario analysis, respectively. To achieve a desired NO x reduction target, China should take strict measures to control NO x emissions, such as improvement in reduction technology, promulgation of new emission standards, and joint control by various Chinese provinces.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.