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© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Phosphides and carbides are among the most promising families of materials based on earth-abundant elements for renewable energy conversion and storage technologies such as electrochemical water splitting, batteries, and capacitors. Nickel phosphide and molybdenum carbide in particular have been extensively investigated for electrochemical water splitting. However, a composite of the two compounds has not been explored. Here, we demonstrate preferential deposition of nickel phosphide on molybdenum carbide in the presence of carbon by using a hydrothermal synthesis method. We employ the hydrogen evolution reaction in acid and base to analyze the catalytic activity of phosphide-deposited carbide. The composite material also shows superior electrochemical stability in comparison to unsupported phosphide. We anticipate that the enhanced electrochemical activity and stability of carbide deposited with phosphide will stimulate investigations into the preparation of other carbide–phosphide composite materials.

Ionic liquids (ILs) have been increasingly recognized as novel solvents for dissolution and pretreatment of cellulose. However, cellulases are inactivated in the presence of ILs, even when present at low concentrations. To more fully exploit the benefits of ILs it is critical to develop a compatible IL-cellulases system in which the IL is able to effectively solubilize and activate the lignocellulosic biomass, and the cellulases possess high stability and activity. In this study, we investigated the stability and activity of a commercially available cellulases mixture in the presence of different concentrations of 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]). A mixture of cellulases and β-glucosidase (Celluclast1.5L, from Trichoderma reesei, and Novozyme188, from Aspergillus niger, respectively) retained 77% and 65% of its original activity after being pre-incubated in 15% and 20% (w/v) IL solutions, respectively, at 50°C for 3 h. The cellulases mixture also retained high activity in 15% [Emim][OAc] to hydrolyze Avicel, a model substrate for cellulose analysis, with conversion efficiency of approximately 91%. Notably, the presence of different amounts of yellow poplar lignin did not interfere significantly with the enzymatic hydrolysis of Avicel. Using this IL-cellulase system (15% [Emim][OAc]), the saccharification of yellow poplar biomass was also significantly improved (33%) compared to the untreated control (3%) during the first hour of enzymatic hydrolysis. Together, these findings provide compelling evidence that [Emim][OAc] was compatible with the cellulase mixture, and this compatible IL-cellulases system is promising for efficient activation and hydrolysis of native biomass to produce biofuels and co-products from the individual biomass components.

Laser-induced breakdown spectroscopy (LIBS), a rapid and potentially field-deployable technology for estimating total carbon in soil, represents a novel approach to address important issues in soil science and carbon management. Our study has shown that models relating LIBS signal intensity at 247.85 nm to percent total carbon determined by dry combustion vary as a function of elemental and textural characteristics of the soil, and, to a lesser extent, wavelength and excitation energy of the laser. To better quantify these sources of variation, two wavelengths and three excitation energies were used to analyze soils from various locations. The emission line of carbon at 247.85 nm was pronounced at an excitation wavelength of 532 nm and energy of 45 mJ, but it was largely obscured by the 248.9 nm Fe line at 1064 nm and excitation energies of 90 and 135 mJ. Univariate analysis revealed linear, but soil-specific correlations between signal intensity at 247.85 nm and total carbon concentration. A single calibration model correlating LIBS spectra to carbon concentration in all samples was obtained using a multivariate approach. Several emission lines in addition to the strong carbon line contributed significantly to the multivariate model. These results show that multivariate analysis can bemore » used to construct a robust calibration model for LIBS spectra and therein provide a reliable estimate of total soil carbon. Such results must be confirmed for a broader range of soils, yet crop and soil scientists, carbon managers, and instrument developers should find these results encouraging.« less

The application of near infrared (NIR) spectroscopy for the prediction of the thermal decomposition behavior of lignocellulosic biomass (three types of woody biomass and three types of herbaceous biomass) was successfully performed along with statistical analysis. The thermal degradation behaviors of the woody and herbaceous biomass were different because of their different chemical compositions. Herbaceous biomass was degraded at lower temperature than woody biomass. The weight-loss profiles as a function of temperature were obtained by thermogravimetric analysis (TGA) at a heating rate of 25°C/min under nitrogen gas. The weight-loss percentage at 10 temperatures in the range 150–600°C was predicted by a wavelet partial least squares (PLS) model, which showed significantly better predictive performance than the ordinary PLS model. The results show that the data predicted by the wavelet PLS model was well fitted to the original data by TGA, in which the root-mean-square error in prediction values less than 5.5 suggested that NIR spectroscopy was applicable for rapid analysis to characterize the thermal decomposition behavior of lignocellulosic biomass for energy production. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009