Constructing noble metal-free electrocatalytically active sites for the simultaneous hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution is key to realizing electricity-driven water splitting in practical applications. Here, we rationally designed Co(OH)@CoSe nanorods (NRs) as an excellent bifunctional electrocatalyst by an electrochemical transformation strategy, where the Co-based nanorod template was converted into Co(OH)@CoSe at the cathode. The obtained electrode exhibits superior electrocatalytic activity for both the HER (overpotential of 208 mV at 20 mA cm) and the OER (268 mV at 20 mA cm) at high current density in a 1 M KOH solution.
View Article and Find Full Text PDFCo-hydrothermal carbonization (HTC) of lignocellulosic biomass and swine manure (SM) was conducted, and the hydrochar properties and transformation behavior of heavy metals (HMs) were investigated in this study. The results showed that co-HTC with lignocellulosic biomass promoted the dehydration of SM and enhanced the aromatization of the hydrochar. Compared to the hydrochar from SM, the carbon content, higher heating value and energy yield of the hydrochar from co-HTC were significantly increased, reaching the maximum of 57.
View Article and Find Full Text PDFAnalysis of soil properties, the compositional traits in bulk soil and different fractions and their responses to afforestation practices may possibly facilitate clarification of the mechanisms underlying soil changes. Soil properties, the compositional functional groups and minerals were determined in the bulk soil and fractions from forests and adjacent farmlands. The afforestation of farmland could induce accumulation of soil organic carbon [SOC] (+18%) and nitrogen [N] (+4%) with pH increase (+4%), and declines in electric conductivity (-15%) and bulk density (-3%).
View Article and Find Full Text PDFThe heavy metals distribution during hydrothermal carbonization (HTC) of sewage sludge, and pyrolysis of the resultant hydrochar was investigated and compared with raw sludge pyrolysis. The results showed that HTC reduced exchangeable/acid-soluble and reducible fraction of heavy metals and lowered the potential risk of heavy metals in sewage sludge. The pyrolysis favored the transformation of extracted/mobile fraction of heavy metals to residual form especially at high temperature, immobilizing heavy metals in the chars.
View Article and Find Full Text PDFThe heteroatoms (N and S) doped porous carbons (HAPCs) were prepared from sewage sludge by hydrothermal carbonization and chemical activation for the first time. The porous structures and surface properties of HAPCs were characterized by multiple techniques including SEM-EDS, TEM, BET, XRD, Raman spectroscopy and Boehm's titration. The resultant materials were showed to be naturally N and S dual-doped porous carbons (HAPCs), especially for HAPC obtained by HCl-HF-washing, which was typical 3D hierarchically porous structure with abundant mesopores as well as big pore diameter.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
October 2016
XRD spectroscopy is an important means of research material inside the crystalline structure of the material. In this study it was analyzed with X-ray sources in terms of manner of preparation of different materials carbon crystal structure of biological characteristics and charring mechanism. The results showed that: Biochar contain d101 and d002 crystal face diffraction peak of carbon graphite-like microcrystalline cellulose, but after charring precipitated salt with different materials, and have a big difference, such as ox dung, castor dregs and furfural dregs of CaCO3 carbon content than other organisms, but only ox dung and castor dregs containing CaMg (CO3)2.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
August 2014
The present paper took the typical saline-alkali soil in Jilin province as study object, and determinated the soil clay mineral composition characteristics of soil in paddy field and dry land. Then XRD spectrum was used to analyze the evolutionary mechanism of clay mineral in the two kinds of soil. The results showed that the physical and chemical properties of soil in paddy field were better than those in dry land, and paddy field would promote the weathering of mineral particles in saline-alkali soil and enhance the silt content.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
April 2014
Infrared spectroscopy (IR) is an important means of seeing the characteristics of the structural properties. Fourier transform infrared spectroscopy (FTIR) was applied to analyze the structural properties of biochar from different materials with different methods. The results showed that: the biochars have IR absorption peaks of hydroxyls group, aromatic group and containing organic group with the activated? charcoal, but in other absorption peaks, with a significant difference.
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