CoNi nano-alloy anchored on biomass-derived N-doped carbon frameworks for enhanced oxygen reduction and evolution reactions

Characterization of moisture migration and diffusion in two types of tobacco biomass during the dehydration process by the TG-NMR analysis

The tobacco waste generated from the tobacco agriculture and industry, including the discarded stem and leaf, often needs dehydration pretreatment before thermal conversion utilization. In order to study the water activity and migration of tobacco waste during the pretreatment process, TG-NMR (Thermogravimetric Nuclear Magnetic Resonance) was used to obtain the drying curves and LF-NMR (Low Field Nuclear Magnetic Resonance) T2 inversion spectrum at each stage of tobacco drying. Meanwhile, the variation pattern of pore distribution during the dehydration process of two types of tobacco waste has been obtained. Combined with the pore distribution changes, a possible spatial migration mode of water was proposed. The change of adsorption energy of water during tobacco drying was calculated, and verified the above hypothesis. This study results provide reference for the optimization of dehydration pretreatment process for different tobacco waste in order to reduce energy consumption during recycling of tobacco biomass.

Facile One-Pot Synthesis of Nickel Nanoparticles by Hydrothermal Method

The one-pot synthesis process has emerged as an economical synthesis method without the involvement of purification or formation of intermediate compounds. Therefore, nickel nanoparticles were selectively synthesized by a simple hydrothermal method using nickel(II) chloride hexahydrate and borane-ammonia complex as a precursor and reducing agent, respectively. The morphology and crystal growth were observed by controlling the precursor concentration ratio of Ni:AB from 1:0.1 to 1:4 under various temperatures ranging from 80 to 140 degrees. In addition, we observed that the crystal growth rate under the influence of NaCl and KCl resulted in spherical Ni particles with size distributions controlled in the range of 297.65 nm to 1082.15 nm and 358.6 nm to 605 nm, respectively.

Fabrication of Trimetallic Fe-Co-Ni Electrocatalysts for Highly Efficient Oxygen Evolution Reaction

The development of inexpensive and well-activated water-splitting catalysts is required to reduce the use of conventional fossil fuels. In this study, a trimetallic Fe-Co-Ni catalyst was fabricated using a simple ion electrodeposition method. The metal deposition was performed using cyclic voltammetry, which was more efficient than constant-voltage deposition and significantly increased the stability of the catalyst. The synthesized material presented the morphology of a nanoflower in which the nanosheets were agglomerated. The Fe-Co-Ni catalyst exhibited excellent oxygen evolution reaction (OER) properties because the charge-transfer rate was improved owing to the synergistic effect of the metals. The OER was performed in a 1 M KOH solution using a three-electrode system, and the overpotential was 302 mV at 100 mA/cm². In addition, the Fe-Co-Ni catalyst exhibited excellent stability in alkaline solution for more than 48 h at 200 mA/cm². The results show that the method for preparing Fe-Co-Ni significantly improves its catalytic activity, and the resulting material could be used as an economical and efficient catalyst in future.

Biomass-Based Oxygen Reduction Reaction Catalysts from the Perspective of Ecological Aesthetics—Duckweed Has More Advantages than Soybean

Ecological aesthetics encourages the harmonization of humans and nature. In this paper, we integrate ecological aesthetics into the development of oxygen reduction reaction (ORR) catalysts of H2/O2 fuel cells. Moldy soybean and duckweed as raw materials are adopted to prepare biomass-based ORR catalysts, both of which have advantages in activity, stability, environmental protection and resource richness over the conventional expensive and scarce noble metal-based catalysts. Therefore, duckweed is more environmentally friendly, entails a simpler preparation process and has a better catalytic performance, ultimately being more in line with ecological aesthetics.