Investigating the Formation Process of Sn-Based Lead-Free Nanoparticles with a Chemical Reduction Method

Nanoparticles of a promising lead-free solder alloy (Sn3.5Ag (wt.%, SnAg) and Sn3.0Ag0.5Cu (wt.%, SAC)) were synthesized through a chemical reduction method by using anhydrous ethanol and 1,10-phenanthroline as the solvent and surfactant, respectively. To illustrate the formation process of Sn-Ag alloy based nanoparticles during the reaction, X-ray diffraction (XRD) was used to investigate the phases of the samples in relation to the reaction time. Different nucleation and growth mechanisms were compared on the formation process of the synthesized nanoparticles. The XRD results revealed different reaction process compared with other researchers. There were many contributing factors to the difference in the examples found in the literature, with the main focus on the formation mechanism of crystal nuclei, the solubility and ionizability of metal salts in the solvent, the solid solubility of Cu in Ag nuclei, and the role of surfactant on the growth process. This study will help define the parameters necessary for the control of both the composition and size of the nanoparticles

Assessing the wind energy potential of China in considering its variability/intermittency

While wind energy experienced massive deployment in the last decades, the intermittency of wind energy hindered its usage and hence leads to curtailment. It is imperative to quantify and mitigate the intermittency/variability of wind energy for research community as well as industry, but there are no consensus methods yet. The present study took the first attempt to quantify the cost of the variability/intermittency of wind energy with battery energy storage system, aiming at comprehensively assessing the spatial distribution of the exploitability of wind energy in China. The research found that the most abundant wind resources are located in Tibet Plateau, Hexi Corridor, Inner Mongolia in considering the abundance of wind resources, land use type, and landforms, as well as the variability of wind energy. In the near future, wind farms with the advanced energy storage technology in 2030 or 2050 could provide stable wind energy with marketing comparable prices, which is lower than the price of current coal-fired electricity (about 0.5 CNY/kWh). It is worth to note that the variability of wind energy in Qinghai Tibet Plateau could lead to high demanding of storage capacity and therefore unaffordable cost. The proposed methodology can be applied in different regions worldwide. The results of this study could also be a scientific foundation for policy makers for wind power development in China mainland

Regular Fe3O4 octahedrons with excellent soft magnetic properties prepared by dealloying technique

The dealloying processes of Al-15Fe (at.%) alloy ribbons consisting of two distinct phases of α-Al (Fe) and AlFe in NaOH solutions were investigated. The effects of NaOH solution concentration, dealloying temperature and time on the results were comparatively discussed. The as-dealloyed samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). It was found that all of the three experimental conditions could affect the morphology of the as-dealloyed samples, and the influence of solution concentration was the crucial factor. The Al could be leached out from both the α-Al (Fe) and AlFe phases to obtain regular octahedral FeO under most of the experimental conditions except for that in the 0.5 mol L NaOH solution at ambient temperature. In particular, the FeO from dealloying Al-15Fe ribbons in 5 mol L NaOH solution for 48 h at ambient temperature shows a uniform octahedral structure (average edge length: 667 ± 158 nm) and special magnetic properties (saturation magnetization: 83.3 emu g, residual magnetization: 10.4 emu g and coercive force: 256.9 Oe), implying its potential applications in magnetic fluid, information storage, etc

Dealloying-directed synthesis of efficient mesoporous CoFe-based catalysts towards the oxygen evolution reaction and overall water splitting

It is a great challenge to design highly active, stable and low-cost catalysts for electrochemically splitting water to realize the clean energy generation and renewable energy storage. Herein, a facile one-step dealloying strategy was proposed to synthesize mesoporous CoFe-based oxides and layered double hydroxides (LDHs). Benefitting from the fast mass transfer and more active sites caused by the open mesoporous structure, the CoFe-based materials exhibit excellent electrocatalytic activities and stability towards the oxygen evolution reaction (OER) in an alkaline electrolyte (1 M KOH). The CoFe-LDH catalyst only needs an overpotential of 0.286 V to achieve 10 mA cm(-2), and a small Tafel slope of 45 mV dec(-1) for the OER. Moreover, an alkaline electrolyzer was constructed with the CoFe-LDH as both the anode and cathode. The electrolyzer delivers a current density of 10 mA cm (2) at a voltage of 1.69 V toward overall water splitting in the 1 M KOH solution